Refills

D1 · D · mini D · mini D1 · standardowy wkład do multipenów · Zebra 4C · 4C-0.4 / 4C-0.5 / 4C-0.7 / 4C-1.0

Length

67 mm

Diameter

2.4 mm

Tip

Metal tube (brass or steel) ending in a ball; two tip styles are common — the classic cone and a needle-point, e.g. the Ohto R-4C7NP with a stainless needle tip and a 0.7 mm TC ball. Typical widths: 0.4–1.0 mm.

A short ballpoint refill for multipens, pocket pens and slim barrels, popularised by Japanese manufacturers. Dimensionally it is the same format as D1 in ISO 12757-1: nominally 67 mm long with a +0.3 mm tolerance (i.e. 67.0–67.3 mm) and 2.35 mm in diameter with a −0.05 mm tolerance (i.e. 2.30–2.35 mm). Real-world examples fall roughly within 66.7–67.3 mm in length and 2.30–2.40 mm in diameter: Ohto specifies 67.3 × 2.3 mm for the R-4C7NP, refill guides measure typical D1 refills at 66.7 mm, and Zebra's are measured at 2.36–2.40 mm. Construction: metal tube, oil-based or low-viscosity ink, conical or needle tips, widths 0.4–1.0 mm.

What fits this barrel

• D1◧needs adjustmentconfirmed

  The reverse direction is benign because nothing collides: a D1 refill at 2.30–2.35 mm drops freely into a tube designed for the thicker 4C at 2.36–2.40 mm. The Bleistift measurements describe exactly this as a loose fit. The refill writes, but there is perceptible lateral play — rattle, and sometimes an off-centre seat in the tip. The usual remedy is a thin sleeve or a wrap of tape around the rear of the refill. That treats the refill, not the pen, and is fully reversible, hence adjustment.

BIC 4-Color refill · BIC 4 Couleurs Recharges · BIC 4 Colours refill

Length

105 mm

Diameter

no data

BIC’s own long stick refill for the 4 Couleurs pen and related BIC multi-pens, replaced individually per colour. Sold in blue, black, red and green with a 1.0 mm (medium) or 0.8 mm (fine) tip. The Pen Refill Guide lists a length of about 105 mm; BIC publishes no dimensions.

What fits this barrel

• 4C□does not fitconfirmed

  A name collision, not a format collision. The slug bic-4c is the refill for the BIC 4 Couleurs: a Japan-type stick 105 mm long that fits some BIC multifunction pens. The slug 4c is the Japanese label for a multipen mini refill, typified by Ohto's R-4C7NP and R-4C5NP, catalogued as D1 refills — roughly 67 mm long and about 2.3 mm across. All they share is the '4C' string in the name. The length gap is about 38 mm and the diameter gap about 0.7 mm (the Japan-type stick runs about 3.0 mm). Neither goes into the other.

• D1□does not fitconfirmed

  Same verdict as for the 4c slug and for the same reason — 4c and d1 are in practice one format under two names. The BIC 4 Couleurs seat is built around a 105 mm Japan-type stick; a D1 refill is about 66.7-67 mm long and about 2.3 mm across, so it is more than a third too short and clearly too thin. Neither the spring nor the colour-slider catch has anything to act on.

Used in the catalogue by: Société BIC 4 Couleurs (4-Color)

BIC Cristal B3 refill · wkład BIC Cristal · B3 stick refill

Length

no data

Diameter

no data

Tip

conical, no collar

A plain stick refill with a cone-shaped tapered tip, no collar and no thread. Refill guides give a length range of 120 mm to 140 mm for this class; no single nominal length or diameter could be confirmed, so the dimension fields are left empty. The best-known example of the format is the BIC Cristal tube. The manufacturer does not describe it as a standard — BIC's own documentation calls it only a "Polypropylene tube with 0.4 grams of ink". The separate catalogue product "BIC Cristal B3 refill" (black, blue, red, green) has been discontinued.

What fits this barrel

• Parker G2□does not fitconfirmed

  Two different constructions. B3 is a plastic stick of variable length (usually 120-140 mm) with a large cone-shaped tip housing that itself locates the refill in the barrel. A Parker-style G2 is a 98.4 mm metal tube with a spring shoulder and its own rear end. Neither the length nor the seating method line up — a G2 has nothing to register against inside a B3 barrel.

Used in the catalogue by: Société BIC Cristal Original

C1 · Cross style · Cross C1 · 8513

Length

115.9 mm

Diameter

no data

A.T. Cross's proprietary ballpoint refill format, roughly 115.9 mm long, recognisable by the knurled, threaded knob at the rear end that screws the refill into the mechanism. Cross identifies its refills by catalogue number — the most common is 8513 (black, medium). The format serves nearly the whole current Cross ballpoint range (Classic Century, Century II, Townsend, ATX, Bailey, Calais and others), and outside Cross it fits most Sheaffer ballpoints plus models from a few smaller makers who design around it. Substitutes come from Monteverde (the C13 series, marketed as "Cross style C1"), Fisher (a pressurized version that writes upside down) and Jaymo.

What fits this barrel

• Parker G2□does not fitconfirmed

  Does not fit — too short and with an entirely different rear end. The Cross Standard (C1) refill is 115.9 mm, about 17.5 mm longer than a Parker G2 (98.4 mm). The C1's identifying feature is a threaded, knurled cap on the back end, which is what the Cross twist mechanism screws onto. A Parker G2 has a plain, unthreaded rear, so even at matching length there would be nothing to engage. The Pen Refill Guide adds that the C1 fits most Cross and Sheaffer ballpoints and that Jaymo and Monteverde make substitutes — in C1 format, not G2.

• Schmidt P900□does not fitconfirmed

  The Schmidt P900 is a Parker-style G2 refill, so the verdict matches parker-g2: roughly 98.4 mm against the 115.9 mm Cross seat. About 17 mm of length is missing and the rear end differs as well (Cross/C1 carries a threaded, knurled knob at the back of the tube). No sensible modification exists here.

D-1 · wkład mini · mini refill · wkład do multipena

Length

67 mm

Diameter

2.4 mm

Miniature ballpoint refill used in multi-function pens and in very slim barrels. Nominal dimensions are 67 mm length (tolerance 0 to +0.3 mm) and 2.35 mm diameter (tolerance −0.05 to 0 mm, a working range of 2.30–2.35 mm). The "D1" designation comes from the classification of refill shapes and dimensions in ISO 12757. Most multipen makers adopted the format, so refills from different brands are in practice interchangeable.

What fits this barrel

• 4C◫needs modificationconfirmed

  Dimensions: D1 per ISO 12757 is 67.0–67.3 mm long (67 mm nominal, +0.3/−0 tolerance) and 2.30–2.35 mm in diameter (2.35 mm nominal, +0/−0.05). 4C refills — sold by Zebra and Fisher among others — share the same nominal ~67 mm length but measure about 2.36–2.40 mm across, above the ISO ceiling. The comparative measurements published on Bleistift show that forcing a 4C into a body designed for D1 widens the holding tube. The body is permanently reamed out afterwards and no longer grips a correct D1 refill, which makes this a modification — and an unwanted one, not a clever hack.

PR4 · SPR4 · Fisher pressurized cartridge · PR cartridge

Length

89 mm

Diameter

no data

Tip

tungsten carbide ball in a stainless steel point; 1.1 mm in the medium (PR4) version

Fisher's hermetically sealed pressurized refill, the PR series. The reservoir is charged with compressed nitrogen (about 310 kPa / 45 psi) that pushes thixotropic gel ink to a tungsten carbide ball set in a stainless steel point, letting it write at any angle, upside down, underwater and over greasy paper. The manufacturer states an operating range of -34 °C to +121 °C. Length is about 89 mm, with a brass barrel (fine-point versions use nickel-silver). PR4 designates black ink with a medium point; other codes in the family vary colour and point width on the same geometry. A plastic adapter is supplied so the refill can also be fitted to pens taking Parker-style refills.

What fits this barrel

• Parker G2□does not fitreported

  Fisher's adapter is one-directional. The PR refill is 88.9 mm (about 89 mm bare, about 99 mm with the supplied plastic adapter, 5.8 mm diameter) and the adapter lets it run in Parker-style G2 bodies. The reverse does not work dimensionally: a full-size G2 is 98.4 mm while Fisher bodies, the Bullet included, are built around the 88.9 mm PR. No open source states outright that a G2 goes into a Bullet, hence 'reported' — the conclusion rests on published lengths, not on a maker's statement.

Used in the catalogue by: Fisher Space Pen Company Bullet Space Pen #400 (chrome) · Fisher Space Pen Company AG7 Original Astronaut Space Pen

8428

Length

96.8 mm

Diameter

6 mm

Tip

stainless steel ball, nickel-plated brass tube

A Caran d'Ache proprietary format used in the 849, Ecridor, Léman, Varius and other standard-size models from the brand. Dimensionally it belongs to the jumbo class, but it conforms to no ISO standard. No other maker offers a substitute in this format.

What fits this barrel

• Parker G2◧needs adjustmentconfirmed

  Fits after adjustment. Bodies designed for the Goliath refill (chiefly the Caran d'Ache 849) accept a Parker G2 refill, which is about 1.6 mm longer than the Goliath (98.4 vs 96.8 mm). The extra length shows up as a tip protruding past the cone when retracted, or a mechanism that will not latch in the writing position. The fix documented by The Gentleman Stationer: unscrew the knock one or two turns, which pulls the tip back into the barrel without introducing play or rattle. The author confirms this with the Schmidt P900 and the uni Jetstream SXR. No permanent change is required, hence adjustment rather than drop-in. The relation is one-way — a Goliath will not fit a Parker G2 body.

• uni SXR (Jetstream)◧needs adjustmentconfirmed

  It goes in, but needs adjusting. Goliath is 96.8 mm and proprietary to Caran d'Ache — no maker offers a substitute. Parker-style refills, the Uni Jetstream SXR among them, are nonetheless run in the 849 barrel: the documented method is unscrewing the rear knock by one or two turns, which pulls the tip back into the barrel. Nothing is permanently altered and the mechanism still works, but the setting has to be dialled in per refill. Metal-tube refills behave best.

• Fisher Space Pen pressurized refill (PR series)□does not fitreported

  No evidence — no guessing. The write-ups covering refill swaps in the 849 list the Jetstream SXR, Schmidt P900, EasyFlow 9000 and Ohto gel refills, but the Fisher refill never appears. In principle the pressurized PR with its Parker-style adapter belongs to the same dimensional family, yet no open source confirms it, and Goliath is 96.8 mm with an unusual rear end. Recorded as unresolved rather than as working.

Used in the catalogue by: Caran d'Ache 849 · Caran d'Ache Ecridor

LAMY M 16 · Großraummine M 16 · giant ballpoint refill

Length

106 mm

Diameter

6 mm

LAMY's proprietary high-capacity ("giant") ballpoint refill, designated M 16. Waterproof per the manufacturer; widths B/F/M, colours black, blue, red and green; dimensions 6 x 6 x 106 mm. The standard refill of full-size LAMY ballpoints, including the LAMY 2000.

What fits this barrel

• Monteverde Soft Roll■fits as isconfirmed

  A drop-in, but only in the Lamy-format version. Monteverde makes Soft Roll in the M16 format too (code L13, "to fit Lamy ballpoint pens"); The Pen Refill Guide lists it at 105.9 mm and says it fits any pen that takes a Lamy M16 refill. The same site notes Monteverde is the only maker of an M16 substitute. Caution: the Parker G2 format Soft Roll (P11/P13/P15) will not fit an M16 body — it is about 7.5 mm too short. The name "Soft Roll" tells you about the ink, never about the shape.

• Parker G2□does not fitconfirmed

  Does not fit — too short. The Lamy M16 refill is 105.9 mm (rounded to 106 mm), while a Parker G2 is only 98.4 mm, leaving about 7.5 mm missing. In a body designed for the M16 the G2 tip never reaches the cone opening and will not deploy when the knock is pressed. The M16 also has its own rear geometry matched to Lamy's mechanism catch. The Pen Refill Guide calls the M16 a proprietary refill and notes Monteverde makes the only substitute for it — which by itself rules out the G2 as a stand-in.

Used in the catalogue by: LAMY LAMY 2000 ballpoint · LAMY cp1

M22 · LAMY Compactmine M 22 · LAMY compact refill

Length

60 mm

Diameter

6 mm

A proprietary, closed LAMY standard for compact ballpoint refills. About 60 mm long, metal-bodied, with oil-based ink the maker calls waterproof; available in F, M and B point widths and in black or blue. Used in the LAMY pico and the LAMY scribble ballpoint (refill guides also list the older agenda and pickup). It matches no entry in ISO 12757 and is not interchangeable with any mainstream market standard.

What fits this barrel

• D1□does not fitconfirmed

  Length alone decides it. The Lamy M22 (Pico, Scribble) is 60.3 mm; a D1 is 67.0–67.3 mm, nearly 7 mm too long for the M22 chamber. In the telescoping Pico that margin matters especially, since refill length sets the whole extension geometry. On top of that the M22 is a short full-diameter ballpoint, not a 2.3 mm stick, so even with the length solved a D1 would swim in the chamber. Naming caution: The Pen Refill Guide files the M22 under "mini ballpoint", which is easily confused with the mini-D1 class — it is not the same format. Lamy's D1-class refill is the M21, not the M22.

• Parker G2□does not fitconfirmed

  The mismatch is far past any montage: 98.4 mm of Parker-style refill against a 60.3 mm M22 chamber, an excess of over 38 mm — more than half the length of the target refill. Cutting is out conceptually too, since a Parker-style refill's ink reservoir runs nearly the full length of the metal tube. The Pen Refill Guide also records that no third-party maker offers a substitute for the M22 — Lamy keeps this format to itself.

Used in the catalogue by: LAMY pico

Soft Roll Ink Technology · Monteverde USA Soft Roll · seria P13x / P15x (format Parker-style G2) · seria L13x (format Lamy) · seria M13x / M14x (format Montblanc) · D13 (format mini D1)

Length

no data

Diameter

no data

Tip

Depends on the host format, not on the ink line. Shared construction: a large-capacity metal tube with a conical ball tip — Monteverde specifies a nickel-plated brass tube and a Swiss tip for the mini D1 version, and a nickel-silver tube and tip for the Parker-style version.

IMPORTANT: "Soft Roll" is NOT a refill format — it is Monteverde USA's ink line (technology), sold in several mutually incompatible host formats. The maker describes it as "Soft Roll™ INK TECHNOLOGY - The latest low viscosity ink for the smoothest writing experience ever!", built as a large-capacity metal refill. Monteverde offers the same ink in at least four formats: Parker-style G2 (P13x/P15x series, about 98.4 mm long), Lamy (L13x series, the Lamy M16 format), Montblanc (M13x/M14x) and mini D1 for multipens (D13). The name "Monteverde Soft Roll" therefore fixes no dimensions on its own — length and diameter come from the format named in the specific product title ("To Fit Parker", "To Fit Lamy", "To Fit Montblanc", "To Fit Multi Functional Pens"). Widths run from extra fine through medium to broad and super broad depending on format, in a wide colour range.

Refill in format: Parker G2 — compatibility is described under the parent format

Parker-style · ISO 12757-2 · G2 (format wkładu)

Length

98.1 mm

Diameter

6 mm

Tip

collared ballpoint refill, flat rear end

The most widely adopted dimensional standard for ballpoint refills, standardised as ISO 12757-2. Nominal length is 98.1 mm, but most refills measure 98.4 mm and manufacturing tolerances spread them across 98–99 mm. That spread matters in practice: in a tight barrel two tenths of a millimetre decide whether the mechanism catches.

What fits this barrel

• Monteverde Soft Roll■fits as isconfirmed

  Soft Roll is a Monteverde ink technology, not a single refill shape — the same ink ships in several body formats. The Parker G2 format version (codes P11 / P13 / P15) measures 98.4 mm and, per The Pen Refill Guide, fits most pens that take a standard Parker G2 refill. It is a drop-in provided you buy the "to fit Parker" variant rather than the Lamy, Montblanc or mini D1 one.

• Schmidt easyFLOW 9000■fits as isconfirmed

  The Schmidt easyFLOW 9000 is a hybrid-ink ballpoint built natively in the Parker G2 format (ISO 12757). Its body length falls in the standard G2 range — The Pen Refill Guide lists the Schmidt P900/P950/P9000 ballpoint family at 98.4 mm. It drops straight into any pen designed for a Parker G2 refill: no spacer, no trimming, no spring swap. Note that the easyFLOW 9000 is a ballpoint, not a rollerball — do not confuse it with Euro Format rollerball refills.

• Schmidt P900■fits as isconfirmed

  The Schmidt P900 (and the related P950 and P9000) is the reference Parker G2 refill at 98.4 mm. The Pen Refill Guide states the P900/P950/P9000 fit most pens that take a G2 refill. It is a drop-in. Nominal standard length is 98.1 mm (ISO 12757-2); shipping refills usually measure 98–99 mm, and that tolerance does not affect fit.

• uni SXR (Jetstream)■fits as isconfirmed

  The answer depends on which SXR you mean. Uni released the SXR-600, the first Jetstream refill built in a Parker G2 body (0.38 / 0.5 / 0.7 mm, black only); The Gentleman Stationer describes it as a Parker-style refill fitting a wide range of pens, and it is a known swap in the Caran d'Ache 849. That one is a drop-in. The classic Japanese Jetstream stick refills for retractable pens (SXR-5 / SXR-7 / SXR-80 family, listed by The Pen Refill Guide at 111.1 mm) are about 13 mm too long and have a different rear end — those will not go into a Parker G2 body. When buying "uni SXR for a Parker", look for the SXR-600 code.

• Fisher Space Pen pressurized refill (PR series)◧needs adjustmentconfirmed

  The bare Fisher PR pressurized cartridge is 88.9 mm (also quoted as 89 mm), roughly 10 mm too short for a Parker G2 body. Fisher solves this in the box: every PR refill ships with a plastic adapter sleeve about 10 mm long that slips onto the rear end, bringing the assembly to about 99 mm and fitting nearly any Parker G2 pen. We classify this as adjustment rather than drop-in — without the adapter it does not work, but fitting the adapter permanently alters neither refill nor pen and is reversible.

• Caran d'Ache Goliath□does not fitconfirmed

  Does not fit. The Caran d'Ache Goliath refill is 96.8 mm, about 1.6 mm shorter than a Parker G2 (98.4 mm), and more importantly it has a different rear end. The Pen Refill Guide puts it plainly: the Goliath is similar in size and shape to a Parker G2 refill but is too short and lacks the correct rear cap to work in pens that take those refills. In practice the mechanism fails to catch the refill and the tip does not deploy properly. The relation is one-way — the reverse (Goliath body, Parker G2 refill) works after adjustment.

• Pilot G2 refill (BLS-G2)□does not fitconfirmed

  IT DOES NOT FIT — and that is the final answer. This is the single most common mix-up in the refill world, because both names contain "G2" while meaning entirely different things. Parker G2 is a refill-shape standard (ISO 12757-2, nominal length 98.1 mm, 98.4 mm as sold) used by dozens of makers. Pilot G2 is Pilot's brand name for a gel pen line; its refill is 111.1 mm long — nearly 13 mm longer — with a different front profile and a different rear end. The Pen Refill Guide titles that refill's page "(Not Parker Style G2)" and its rollerball guide states that Pilot G2 gel refills will NOT fit pens taking a Parker style G2. No adjustment fixes this: the length gap is far too large, and shortening a gel refill would breach its seal. If you want gel ink in a Parker G2 body, buy a gel refill built to the G2 format (Monteverde or Schmidt gel versions, for example), not a refill from a Pilot G2 pen.

Used in the catalogue by: Parker Pen Company Jotter

XLR / XLRN (oznaczenia z katalogu japońskiego) · wkład EnerGel · „G2-size” (nieformalne, mylące określenie w bazach społecznościowych)

Length

112 mm

Diameter

6.2 mm

Tip

conical metal (LR) or needle (LRN)

Pentel's proprietary gel refill for the whole EnerGel line: about 112 mm long, max body width about 6.2 mm, quick-drying dye-based ink. Two tip families: LR — conical metal (LR7 0.7 mm, LR10 1.0 mm) and LRN — needle (LRN3/LRN4/LRN5), plus the pigmented LRP ("permanent") variant. One format fits every refillable EnerGel body; Japanese catalogue codes carry an X prefix (XLR7, XLRN5).

What fits this barrel

• Pilot G2 refill (BLS-G2)◧needs adjustmentreported

  The mirror case, documented symmetrically: the Pilot G2 refill entry states it will sometimes fit pens that take a Pentel EnerGel refill. Length is identical at 111.1 mm, so the constraint is not length but how the tip cone seats in the front aperture and how the spring is captured. No permanent work is involved, but no blanket guarantee across body models either.

• uni SXR (Jetstream)□does not fitconfirmed

  The same arithmetic as for a Pilot G2 body: the Jetstream SXR is 117.5 mm against the 111.1 mm EnerGel LR format, an excess of about 6.4 mm that jams the mechanism. The Jetstream is also a ballpoint with a different tip-cone profile from the EnerGel's metal needle tip, so even with the length solved it would not be a geometrically neutral swap at the front section.

Used in the catalogue by: Pentel EnerGel (standardowy model przyciskowy, BL77 / BLN75)

BLS-HC25 · BLS-HC3 · BLS-HC4 · BLS-HC5

Length

no data

Diameter

no data

Tip

tubular needle tip with three-point ball support

Pilot's proprietary gel refill for the capped Hi-Tec-C pens. Part numbers track ball size: BLS-HC25 (0.25 mm), BLS-HC3 (0.3 mm), BLS-HC4 (0.4 mm), BLS-HC5 (0.5 mm). The fine stainless-steel pipe tip, with three dimples holding the ball (Pilot's three-point support), is part of the refill, so changing the refill changes the whole writing tip. The refill carries biopolymer (gel) ink. No open source states the refill's length or barrel diameter, so those fields are left empty.

What fits this barrel

• Pilot Hi-Tec-C Coleto (LHKRF)◧needs adjustmentconfirmed

  The answer to "does anything fit a bls-hc body" is yes, and it is documented by the body's maker. CW&T, who build the Pen Type-A and Type-B around the Hi-Tec-C cartridge, state in their FAQ that with a small spacer the pen accepts ten other cartridges, naming Pilot Coleto among them. The spacer takes up the length difference and is a removable part — nothing is cut — hence adjustment. Scope: confirmed for CW&T bodies, the best-documented corpus in this standard; we found no confirmation for Pilot's own plastic barrels. The BLS-HC refill length could not be established from a dimensional source and is not published here.

• Pilot FriXion LFBKRF◧needs adjustmentreported

  The same mechanism as for Coleto: CW&T's FAQ lists "Pilot Frixion" among the cartridges that go into a Pen Type-A once a small spacer is added. Status is reported rather than confirmed for one reason: the source names the family, not the part number, and Frixion spans several formats (the Frixion Ball refill plus separate refills for the multi and clicker versions). Until the exact part tested is confirmed, mapping it to the pilot-frixion-lfbkrf slug is an inference, not a quotation. The grade itself — spacer, no permanent change — is consistent with the rest of CW&T's list.

Used in the catalogue by: Pilot Corporation Hi-Tec-C

BRFN-10F · BRFN-30F · BRFN-30M · uni SE-7 · Tombow BR-VS · Pentel KFS7 · Pentel KFS5 · Platinum BSP-100S · Sailor 18-0103

Length

86.8 mm

Diameter

6 mm

Japanese oil-based refill with a plastic body, 86.8 mm long and 6 mm at its widest point, filled with Pilot Acro ink. Pilot's own compatibility chart files it as the refill "for higher-priced writing instruments and for Dr. Grip". Tip sizes: 0.7 mm (BRFN-10F, BRFN-30F) and 1.0 mm (BRFN-30M). The same chart lists competitors' refills that Pilot considers dimensionally interchangeable: uni SE-7, Tombow BR-VS, Pentel KFS7 and KFS5, Platinum BSP-100S, Sailor 18-0103, with Pilot's own caveat that the match is dimensional and writing performance may differ.

What fits this barrel

• Parker G2□does not fitconfirmed

  A closed format. The BRFN-30 is 86.5 mm and is Pilot's alone — it serves the Center of Gravity line among others, and in a plastic tube the Dr. Grip as well. No third party offers an equivalent. A Parker-style G2 (98.4 mm) is about 12 mm too long and has a different rear end, so there is neither a swap nor a sensible adjustment. The answer to 'pilot-brfn takes anything' is: nothing but Pilot's own refill.

Used in the catalogue by: Pilot Corporation Dr. Grip

LHKRF · ハイテックCコレト専用レフィル · Coleto refill

Length

126 mm

Diameter

3.1 mm

Pilot's modular gel refill for the Hi-Tec-C Coleto system, coded LHKRF. The ink is a water-based gel that Pilot calls 水性バイオポリマーインキ; ball sizes are 0.3 / 0.4 / 0.5 mm. The refill is 126 mm long with a φ3.1 mm body and carries an integral side slide-lever moulded in the ink colour, which both extends the tip and identifies the colour inside the barrel. The same slot also takes non-writing units: a mechanical pencil, a retractable eraser and a discontinued stylus. Pilot lists the compatible units for its bodies as LHKRF-10C3, LHKRF-10C4, LHKRF-10C5, LHKRF10S4, LHKRF-18H5, LHKRF-18H3, LHKRF-28E.

What fits this barrel

• 4C□does not fitconfirmed

  The same reasoning as for D1, only stronger. A 4C is the same ~67 mm long but 2.36–2.40 mm across, so thicker than D1, and it still lacks everything a Coleto module needs: its own push button, keying fins that ride in the barrel grooves, and the ability to be dropped in from the side after opening the top lid. Pilot's manual settles it formally; the geometry settles it practically. Housekeeping note: 4C is sometimes mislabelled "Zebra's D1", which invites attempts to push it into multi pens — in a Coleto barrel there is not even a place to try.

• D1□does not fitconfirmed

  Coleto is a closed system and the maker says so: Pilot's English use-and-care guide states the body and refill are designed specifically for the HI-TEC-C COLETO and are not compatible with other products. The reason is mechanical, not commercial — a Coleto refill is a complete module with its own click button and keying fins that slot into grooves in the barrel, and it loads from the side rather than the front. A D1 refill is a bare 67 mm × 2.3 mm stick with no button, no fins and nothing for the mechanism to grab. No D1-to-Coleto adapter description could be opened or verified; the one accessible source on cross-system multi-pen swaps refers only to heavy modification without giving a procedure. The Coleto refill length is deliberately not published here — the single catalogue figure found is inconsistent with the physical module.

• uni SXR (Jetstream)□does not fitconfirmed

  Two separate obstacles. First, the stick-format Jetstream SXR is 117.5 mm long and is an ordinary single-colour pen refill — a Coleto module has neither the room nor the catch for it. Second, uni runs its own equally closed multi-pen system (Style Fit / Jetstream multi), and The Gentleman Stationer's side-by-side of the two systems states plainly that Coleto and uni refills are not interchangeable short of heavy modification, each being a proprietary design matched to its own maker's barrels. Pilot's manual prohibition sits on top of that.

Used in the catalogue by: Pilot Corporation Hi-Tec-C Coleto (ハイテックCコレト)

LFBKRF-30EF · LFBKRF-30F · LFBKRF-12EF · LFBKRF-12F · BLS-FR5 · BLS-FR7

Length

111 mm

Diameter

6 mm

Tip

conical

Pilot's proprietary refill format for single-colour FriXion pens, filled with thermochromic FriXion gel ink (microcapsules containing a leuco dye, a colour developer and a colour-change regulator). A plastic tube 111 mm long with a 6.0 mm maximum diameter and a conical metal tip (manufacturer figures for the 0.5 mm version). Ball sizes 0.5 mm (LFBKRF-30EF, -12EF) and 0.7 mm (LFBKRF-30F, -12F); 30 denotes a three-pack, 12 a single refill. In Europe the same refill is sold as BLS-FR5 and BLS-FR7. Pilot's compatibility chart assigns it to the capped FriXion Ball (LFB-20EF, LFB-20F), the retractable FriXion Ball Knock (LFBK-23EF, LFBK-23F, LFBK-2SEF) and FriXion Ball Biz (LFBN-150EF). The refill body is tinted because the ink colour inside the tube does not match the colour written on paper. No ISO standard covers this format.

We have documented no compatibility with another format for this standard.

Used in the catalogue by: Pilot Corporation FriXion Ball

BLS-G2 · LG2RF (Japonia) · Pilot G2 size

Length

110.5 mm

Diameter

6.2 mm

Tip

conical

Pilot's gel refill for the G-2 series and related models (G6, Dr. Grip Gel, G-Knock, B2P): a plastic tube about 110.5 mm long with a 6.2 mm max diameter, conical tip, ball sizes 0.38-1.0 mm. Sold as BLS-G2 in the US and Europe and as LG2RF in Japan. It is not a formal standard — it is Pilot's proprietary format that, through the G-2's popularity, became the de facto reference for Japanese gel refills.

What fits this barrel

• Pentel LR / LRN (EnerGel)◧needs adjustmentreported

  Both refills are catalogued at the same 111.1 mm (4.375") length and both are Japanese plastic gel sticks. The Pen Refill Guide stops short of claiming full interchange: it says the EnerGel fits SOME pens built for a Pilot G2 refill. The variables are tip-cone diameter, shoulder position against the front section, and the rear profile the spring seats on, so a spacer or re-seated spring is sometimes needed. Those steps are reversible and require no cutting, hence adjustment rather than drop-in.

• Parker G2□does not fitconfirmed

  IT DOES NOT FIT — the other side of the same mix-up, equally settled. Inside a Pilot G2 pen body, a Parker G2 refill (98.4 mm) is about 13 mm shorter than the factory gel refill (111.1 mm). The consequence is immediate: the tip never reaches the cone opening and will not deploy when the knock is pressed, and the refill would rattle inside the barrel. On top of that, Pilot's mechanism catch is shaped for a different rear end. The Pen Refill Guide states outright that Parker style G2 refills will NOT fit in a Pilot G2 pen. Remember the rule symmetrically: Parker G2 and Pilot G2 share nothing but two characters in the name.

• Sakura Ball Sign□does not fitreported

  No dimensional source confirmed either the length or the diameter of the Sakura Ballsign refill, so the measurement is left empty and deliberately no number is published. The Ballsign family also splits into stick refills (R-GBN for Ballsign iD) and multi-pen refills (R-GBH for Ball Sign 4+1), which are quite different sizes, so the slug alone does not pin down the geometry. The 'no' grade rests solely on the absence of any documented fit in Pilot G2 bodies, not on a measured clash. Flagged for physical measurement.

• uni SXR (Jetstream)□does not fitconfirmed

  The uni-ball Jetstream SXR refill is 117.5 mm (4.625") long, about 6.4 mm longer than the Pilot G2 format at 111.1 mm. Six millimetres of excess is not assembly slack: the knock mechanism will not latch, or the tip stays permanently extended. Trimming the plastic barrel of such sticks is a known practice, but it is irreversible and we found no source documenting it for this specific pair, so we do not grade it as modification.

R-PGB (Ball Sign 80) · R-GBP (Ballsign Knock) · R-GBN (Ballsign iD) · R-GBM / R-GBH / R-GBHN (korpusy wielokolorowe)

Length

no data

Diameter

no data

Sakura's proprietary family of gel refills for Ball Sign pens — not an international standard and not interchangeable with Parker G2 or D1. The manufacturer publishes a compatibility table in which each body is matched to a refill with its own code: R-PGB#49 for the Ball Sign 80, R-GBP04/05 for the retractable Ballsign Knock, R-GBN04/05 for the Ballsign iD, and R-GBM/R-GBH/R-GBHN for multi-colour bodies. Refills differ in length and shape within the family; there is no single shared dimension across the line, and several rows in the table are flagged as withdrawn (廃止) or scheduled for withdrawal (廃止予定). Dimensions are left empty because the manufacturer publishes no millimetre data in that table.

We have documented no compatibility with another format for this standard.

Used in the catalogue by: Sakura Color Products Ball Sign 280 (ボールサイン280)

Schmidt P9000 · easyFLOW 9000M · Schmidt Easy Flow 9000 · wkład Parker-style G2 (hybrydowy)

Length

98.4 mm

Diameter

5.8 mm

Tip

Tapered metal cone with a tungsten-carbide (TC) ball, 0.8 mm or 1.0 mm, supplied with a tip protection cap. The tapered front section runs about 23.2 mm; the rear end is the G2-typical embedded plastic end piece with ratcheting grooves.

Hybrid ballpoint refill by Germany's Schmidt Technology in the G2 (Parker-style) format. Yes — it is a Parker G2 refill: the manufacturer calls it a "New refill type in G2 format" and states the easyFLOW system is available in the G2 large-capacity size and the D style per DIN ISO 12757; independent guides place it under ISO 12757-1. The ink is a hybrid, combining the fast-drying behaviour of oil-based ballpoint paste with rollerball-like smoothness, so it writes the moment it touches paper. Real dimensions: the ISO nominal length is 98.1 mm, but actual G2 refills — Schmidt's included — measure about 98.4 mm (3 7/8"), with a production spread of 98–99 mm; body diameter is about 5.8 mm. Versions: 0.8 mm TC ball (F) and 1.0 mm TC ball (M). It fits any barrel that takes a Parker G2 refill.

Refill in format: Parker G2 — compatibility is described under the parent format

P8127 short · 8127P · Retro 51 capless rollerball · short capless rollerball 97.5 mm

Length

97.5 mm

Diameter

6.9 mm

Tip

rollerball, 0.7 mm ceramic ball

A capless capillary rollerball refill by Schmidt Technology of Germany: metal tube and front section, stainless-steel tip with a 0.7 mm ceramic ball, one-year cap-off time. Dimensions 97.5 mm x 6.9 mm — the external envelope matches Parker-style (G2) ballpoint refills, which is why G2 ballpoint refills fit the same pens. Factory refill of the Retro 51 Tornado; the P8126 variant carries a 0.6 mm (fine) ball.

What fits this barrel

• Schmidt P900◧needs adjustmentreported

  Sometimes, not always. The P8127 is a capless rollerball 97.5 mm long and 6.9 mm across — close in length to a Parker-style G2 (98.4 mm), but the tube is noticeably thicker and shaped differently at the front. Some barrels built around the short capless rollerball (the Retro 51 Tornado is the standard example, also sold as a ballpoint on a Parker-style refill) take a P900 with no work, but this is not a rule and tip protrusion usually has to be dialled in. The relation is not symmetric: barrels designed only for G2 generally will not take the short rollerball.

• Parker G2□does not fitreported

  Does not fit. These are two different systems, not two variants of one. The Schmidt P8127 (P8120/P8126/P8127 family) is a capless rollerball refill: the tip-sealing mechanism lives in the refill itself, not in the pen. The dimensions diverge too — the P8127 is 97.5 mm long and about 6.9 mm in diameter, while a Parker G2 refill is 98.4 mm with a distinctly thinner body (sources quote 5.8-6.3 mm; we do not treat any single figure as canonical). A G2 ballpoint dropped into a P8127 socket would sit with radial play and could not provide the seal the body was built around. Status is reported because no open source addresses this exact pair directly — the conclusion rests on documented dimensions and construction of both standards, not on a quoted interchangeability claim.

Used in the catalogue by: Retro 51 Tornado

Schmidt P 900 · P900 G2 · wkład Parker-style G2 · Standard International Ballpoint Refill

Length

98.4 mm

Diameter

5.8 mm

Tip

Tapered metal cone with a stainless-steel tip and a tungsten-carbide (TC) ball. Front tapered section about 23.2 mm; rear end an embedded plastic piece with ratcheting grooves. Line widths F, M and B.

Schmidt Technology's baseline ballpoint refill in the G2 (Parker-style) format per DIN ISO 12757 — the maker describes it as a "G2 large capacity refill with stainless steel tip and TC ball". Oil-based ballpoint paste, offered in F, M and B in black and blue, plus M in red, green, magenta, turquoise and violet. Geometry: about 98.4 mm long (ISO nominal 98.1 mm, spread 98–99 mm), body diameter about 5.8 mm. Interchangeable with Parker's own refills and other G2 refills.

Refill in format: Parker G2 — compatibility is described under the parent format

SXR-38 · SXR-5 · SXR-7 · SXR-10 · SXR-L-5/-L-7 · SXR-71 · SXR-80 · SXR-89 (Style Fit) · SXR-200 · SXR-203 · SXR-600 (Parker-style)

Length

no data

Diameter

no data

Tip

conical

Mitsubishi Pencil's OEM family of oil-based refills with low-viscosity Jetstream ink. Sub-families map to specific bodies: SXR-38/-5/-7/-10 — standard single-color pens (SXN-150 and relatives), SXR-71 — international SXN-101, SXR-80 — multicolor pens, SXR-89 — the Style Fit system, SXR-200 — Prime multicolor, SXR-203 — the Edge line (0.28/0.38 mm), SXR-600 — the Prime single twist pen. The SXR-600 is deliberately made to the Parker-style (G2) form factor, so it also fits third-party bodies — the one such exception in the family; the remaining sub-families are proprietary and mutually non-interchangeable.

We have documented no compatibility with another format for this standard.

Used in the catalogue by: uni (Mitsubishi Pencil Co., Ltd.) Jetstream (standard)

Zebra F · F-refill · 85511 · 85512 · 89112 (All Metal F-Refill)

Length

88.9 mm

Diameter

no data

Zebra's own ballpoint refill in a proprietary, non-standardised shape, used across the stainless-steel F-series: F-301, F-301A, F-301 Compact, F-402 and F-701. Length about 88.9 mm (3.5 in). Offered in 0.7 mm, 1.0 mm and 1.6 mm, in black, blue and red; the All Metal F-Refill variant (0.8 mm, SKU 89112) was created for the F-701 ALL METAL. It does not fit the brand's gel G-series barrels. No third-party maker offers an equivalent, but the refill's profile is close to the Fisher Space Pen pressurised family, which makes those a practical substitute in some barrels.

What fits this barrel

• Fisher Space Pen pressurized refill (PR series)■fits as isreported

  Start from the dimensions: The Pen Refill Guide gives both refills the same 88.9 mm (3.5") length and describes their profiles as comparable; thepenbridge catalogues the Zebra F refill at approximately 89 mm. On the bodies, though, generations must be separated. Today's almost-all-metal F-701 — Zebra brought that version out in 2018 along with a clicker mechanism revised for a metal cartridge — is reported to take the Fisher PR pressurized refill without modification. Older bodies did not: a small plastic cone sat inside the tip and had to be pushed out before the Fisher refill would seat, as The Clicky Post and Three Points of the Compass independently describe. A removed cone is irreversible, so for pre-2018 examples the correct grade is modification. Status is reported because both claims come from enthusiast publications — neither Zebra nor Fisher confirms the interchange in company material, and thepenbridge lists the Fisher refill against the Zebra as a "modification or comparison only" option.

Used in the catalogue by: Zebra F-701

M66 · 1605757

Length

110 mm

Diameter

6.8 mm

Tip

metal body with a conical metal tip

LAMY's proprietary rollerball refill for capless bodies. The maker gives dimensions of 7 × 7 × 110 mm and states the fit in one sentence: capless rollerballs and the imporium — that is, the swift, tipo and dialog 2. Available in two widths (M, B) and four ink colours; there is no F. The format is closed: no other brand sells a drop-in equivalent, and every working substitution is a user-side modification. The body measures about 6.8 mm, noticeably thicker than Japanese gel refills at 6.0–6.2 mm, so any substitute sits with play.

What fits this barrel

• Pilot G2 refill (BLS-G2)◧needs adjustmentconfirmed

  A Pilot G2-family refill goes in once the rear plug is removed, but it is the loosest fit measured: a 6.0 mm body against the original's 6.8 mm, with overall length coming out slightly short. The author of the measurements reports pronounced wobble when writing at an angle and rates the writing poor. The work is done to the refill and is reversible, hence adjustment.

Used in the catalogue by: LAMY swift

JF-0.5 · RJF5 · P-RJF5 · JF-0.4 · JF-0.7 · JF-1.0

Length

111.1 mm

Diameter

no data

Tip

conical, 0.3–1.0 mm ball depending on variant

Zebra's OEM gel refill for the Sarasa family. The Japanese catalogue lists it as JF-0.5芯, retail packaging as RJF5 (P-RJF5 for export). Since 1 August 2024 the refill tube has been made from sugarcane bioplastic while keeping the same code and dimensions, so old and new are mutually interchangeable. The maker's official compatibility list covers exactly four bodies: Sarasa, Sarasa Clip, Sarasa Grand and Sarasa Nano.

We have documented no compatibility with another format for this standard.

Used in the catalogue by: Zebra Sarasa Clip

BKL7 · BKL10

Length

no data

Diameter

no data

Tip

conical, 0.7 mm ball (BKL7) or 1.0 mm (BKL10)

Pentel's OEM ballpoint refill family for the R.S.V.P. and related models. The BKL7 (0.7 mm) serves the R.S.V.P. BK90 as well as the BK77, BK77AB, BK401 and BK127; the BKL10 (1.0 mm) is described by the maker as made exclusively for the R.S.V.P. BK91. The digit in the code is the ball diameter.

We have documented no compatibility with another format for this standard.

Used in the catalogue by: Pentel R.S.V.P.

UMR-1 · UMR-1-05 · UMR-1-28 · UMR-5

Length

115 mm

Diameter

no data

Tip

needle-point, 0.28 / 0.38 / 0.5 mm ball depending on variant

Mitsubishi Pencil's OEM gel refill for Signo bodies in the UM-151 family. The digit after the hyphen is the ball diameter, its absence meaning the default 0.38 mm: the UMR-1 fits the UM-151, the UMR-1-05 the UM-151-05, the UMR-1-28 the UM-151-28. The refill is about a centimetre shorter than comparable gel refills from other brands, which in practice rules out substitution in either direction.

We have documented no compatibility with another format for this standard.

Used in the catalogue by: uni (Mitsubishi Pencil Co., Ltd.) uni-ball Signo UM-151