# Grease (Zerk) fittings: SAE-LT 1/4-28, 1/8 PTF and DIN 71412 forms A, B, C (M6, M8, M10, R1/8, R1/4) — hex size, overall length, 45° / 90°

> What hex size and thread does a grease zerk fitting have, and how long are the straight, 45° and 90° types?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: Alemite's data sheets for 1/4-28 SAE-LT and 1/8 PTF fittings (with McMaster-Carr's category table as a cross-check), AFT / Kipp K1132 data sheets for DIN 71412 forms A and B, Bollhoff's form C sheet and a Wuerth form B listing; numbers only
- Page: https://xemstudio.com/objects/grease-fittings-sae-j534-din-71412/ · JSON: https://xemstudio.com/api/geometry?object=grease-fittings-sae-j534-din-71412 · Plain text: https://xemstudio.com/objects/grease-fittings-sae-j534-din-71412/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no tolerance added.

## Notes

- SAE grease fittings (the 'Zerk' type): the common thread is 1/4-28 taper, called SAE-LT on the Alemite sheets, assembled into a 1/4-28 UNF class 3B straight threaded hole (Alemite: modified maximum minor diameter 0.2151 in), and 1/8 PTF (Dryseal pipe thread, tapered; the Alemite sheet prints 'SAE SPL' on the short ones). The SAE J534 document itself was not read, so no value is attributed to it; the rows are the makers' tables. Alemite's columns: hex size, overall length, shank length. Straight 1/4-28 fittings are 5/16 in hex (3/8 in hex for the angled ones), 17/32 to 1-5/8 in overall; 1/8 PTF fittings are mostly 7/16 in hex.
- McMaster-Carr's table for zinc-plated 1/4-28 SAE-LT fittings agrees on hex size and overall length with Alemite for the straight 35/64, 11/16, 31/32, 1-1/8 and 1-5/8 in fittings and the 3/4 in 90° one, but its 'thread length' column (7/64, 13/64, 13/64, 13/64, 1/4 in) is not Alemite's shank length (3/16, 23/64, 5/8, 25/32, 1 in); Alemite's 45° 13/16 in fitting has a 13/64 in shank against McMaster's 5/32 in thread length. McMaster also lists self-tapping, 65° and 303 stainless fittings; only the plain ones are shown. Drive-type (push-in) fittings and the double 70° fitting on the Alemite sheets are not tabulated.
- DIN 71412 (conical-head grease nipples): the AFT / Kipp K1132 sheets give form A (straight) and form B (45°) for M6x1, M8x1, M8x1.25, M10x1, M10x1.5, R1/8 and R1/4, with their own letters (A, D, L1, L max, SW) that the sheet does not define; SW is read as the hex wrench size since it matches the usual values (7, 9, 11, 14 mm). Form C (90°, Bollhoff): M6x1 and M8x1 s 9 mm, l 14.3 mm; M10x1 s 11 mm, l 15.3 mm. A Wuerth form B M10x1 listing prints thread length 5.5 mm, wrench size 11 and overall length 25 mm; AFT's form B prints L max 23 for the same nut, so the overall length of form B is shown as printed by each. Form A SW for M6 is 7 mm (AFT) and for form C Bollhoff prints 9 mm: the forms have different hex sizes. The DIN text itself was not read. Steel versions are hardened to min 550 HV 1 and zinc-plated; stainless to 1.4305 (AFT).
- No file: the ball-check head profile (spherical head diameter, neck) and the hex height are not published as numbers in any source read; a hex-plus-cylinder envelope would not describe the part. McMaster-Carr sells grease fittings with per-part STEP; its 1/4-28 SAE-LT category is linked, not copied. Thread data for the pipe-thread versions: npt-thread-dimensions-asme-b1-20-1, an-jic-37-degree-flare-fittings.

## Sizes

| source / series | part or material | thread | form / angle | hex (AF) | overall length | shank / thread length / other | note |
|---|---|---|---|---|---|---|---|
| Alemite, 1/4-28 taper (SAE-LT) | 1641-B | 1/4-28 SAE-LT | straight | 5/16 in | 35/64 in | 3/16 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1652-B | 1/4-28 SAE-LT | straight | 5/16 in | 11/16 in | 23/64 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1680-B | 1/4-28 SAE-LT | straight | 5/16 in | 31/32 in | 5/8 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1698-B | 1/4-28 SAE-LT | straight | 5/16 in | 1-1/8 in | 25/32 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 3014-B | 1/4-28 SAE-LT | straight | 5/16 in | 1-5/8 in | 1 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1637-B1 | 1/4-28 SAE-LT | 45° | 3/8 in | 13/16 in | 13/64 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 3010-B1 | 1/4-28 SAE-LT | 65° | 3/8 in | 25/32 in | 19/64 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1911-B1 | 1/4-28 SAE-LT | 90° | 3/8 in | 3/4 in | 13/64 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1966-S (stainless) | 1/4-28 SAE-LT | straight | 5/16 in | 17/32 in | 3/16 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1968-S (stainless) | 1/4-28 SAE-LT | 45° | 3/8 in | 13/16 in | 13/64 in (shank) | Alemite data sheets |
| Alemite, 1/4-28 taper (SAE-LT) | 1969-S (stainless) | 1/4-28 SAE-LT | 90° | 3/8 in | 3/4 in | 13/64 in (shank) | Alemite data sheets |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1644-B | 1/8 PTF | straight | 7/16 in | 9/16 in | 15/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1610-BL | 1/8 PTF | straight | 7/16 in | 11/16 in | 19/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1607-B | 1/8 PTF | straight | 7/16 in | 1-1/4 in | 25/32 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1669-B | 1/8 PTF | straight | 7/16 in | 1-3/4 in | 1-17/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1618-B | 1/8 PTF | straight | 1/2 in | 1 in | 9/32 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1958 | 1/8 PTF | straight | 7/16 in | 31/32 in | 1/4 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1611-B | 1/8 PTF | 30° | 7/16 in | 29/32 in | 19/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1688-B | 1/8 PTF | 45° | 7/16 in | 57/64 in | 19/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1620-B | 1/8 PTF | 45° | 7/16 in | 1-1/8 in | 13/32 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1612-B | 1/8 PTF | 65° | 7/16 in | 27/32 in | 19/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1613-B | 1/8 PTF | 90° | 7/16 in | 27/32 in | 19/64 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1606-B | 1/8 PTF | 90° | 7/16 in | 1-13/16 in | 1-1/4 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1961-S (stainless) | 1/8 PTF | straight | 7/16 in | 3/4 in | 5/16 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1921-S (stainless) | 1/8 PTF | 30° | 7/16 in | 1-1/4 in | 11/32 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1922-S (stainless) | 1/8 PTF | 67.5° | 7/16 in | 61/64 in | 11/32 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| Alemite, 1/8 PTF (sheet labels 'SAE SPL') | 1923-S (stainless) | 1/8 PTF | 90° | 7/16 in | 7/8 in | 11/32 in (shank) | Alemite data sheets; 1/8 PTF is a tapered pipe thread |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | straight | 5/16 in | 35/64 in | 7/64 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | straight | 5/16 in | 11/16 in | 13/64 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | straight | 5/16 in | 31/32 in | 13/64 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | straight | 5/16 in | 1-1/8 in | 13/64 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | straight | 5/16 in | 1-5/8 in | 1/4 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | 303 stainless | 1/4-28 SAE-LT | straight | 5/16 in | 17/32 in | 7/64 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | 303 stainless | 1/4-28 SAE-LT | straight | 9/32 in | 19/32 in | 7/32 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | 90° | 3/8 in | 3/4 in | 5/32 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | 90° | 3/8 in | 51/64 in | 5/16 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | 65° | 3/8 in | 49/64 in | 13/64 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | 45° | 3/8 in | 13/16 in | 5/32 in (thread length) | category table as printed |
| McMaster-Carr, 1/4-28 SAE-LT (as printed) | zinc-plated steel | 1/4-28 SAE-LT | 45° | 3/8 in | 63/64 in | 5/16 in (thread length) | category table as printed |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | M6x1 | M6x1 | A, 0° | 7 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | M8x1 | M8x1 | A, 0° | 9 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | M8x1.25 | M8x1.25 | A, 0° | 9 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | M10x1 | M10x1 | A, 0° | 11 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | M10x1.5 | M10x1.5 | A, 0° | 11 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | R1/8 | R1/8 | A, 0° | 11 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form A, straight (AFT / Kipp K1132, mm) | R1/4 | R1/4 | A, 0° | 14 mm (SW) | L1 16 mm | D 6 mm | letters as printed on the sheet, not defined there |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | M6x1 | M6x1 | B, 45° | 9 mm (SW) | L max 23 mm | L1 5.5 mm; A 10.5 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | M8x1 | M8x1 | B, 45° | 9 mm (SW) | L max 23 mm | L1 5.5 mm; A 10.5 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | M8x1.25 | M8x1.25 | B, 45° | 9 mm (SW) | L max 23 mm | L1 5.5 mm; A 10.5 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | M10x1 | M10x1 | B, 45° | 11 mm (SW) | L max 23 mm | L1 5.5 mm; A 11.5 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | M10x1.5 | M10x1.5 | B, 45° | 11 mm (SW) | L max 23 mm | L1 5.5 mm; A 11.5 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | R1/8 | R1/8 | B, 45° | 11 mm (SW) | L max 23 mm | L1 5.5 mm; A 11.5 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form B, 45° (AFT / Kipp K1132, mm) | R1/4 | R1/4 | B, 45° | 14 mm (SW) | L max 23 mm | L1 5.5 mm; A 12 mm | letters as printed; Wuerth M10 form B: overall 25 mm, thread length 5.5, SW 11 |
| DIN 71412 form C, 90° (Bollhoff, mm) | M6x1 | M6x1 | C, 90° | 9 mm (s) | 14.3 mm (l) | — | Bollhoff steel 5.8 zinc, conical thread |
| DIN 71412 form C, 90° (Bollhoff, mm) | M8x1 | M8x1 | C, 90° | 9 mm (s) | 14.3 mm (l) | — | Bollhoff steel 5.8 zinc, conical thread |
| DIN 71412 form C, 90° (Bollhoff, mm) | M10x1 | M10x1 | C, 90° | 11 mm (s) | 15.3 mm (l) | — | Bollhoff steel 5.8 zinc, conical thread |

## Where the files are

- Alemite: [1/4-28 taper (SAE-LT) hydraulic grease fittings: 1641-B, 1652-B, 1680-B, 1698-B, 3014-B straight, 1637-B1 45 deg, 3010-B1 65 deg, 1911-B1 90 deg: hex, overall length, shank length](https://cdn.shopify.com/s/files/1/1425/8938/files/Alemite-1641-B-Straight-Hydraulic-One-Quarter-Inch-Twenty-Eight-Thread-Grease-Fitting.pdf) — web — Maker data sheet; numbers only
- Alemite: [1/8 PTF hydraulic grease fittings (labelled SAE SPL on the sheet): straight, 30, 45, 65, 90 deg: hex, overall length, shank length](https://cdn.shopify.com/s/files/1/1425/8938/files/Alemite-1688-B-Hydraulics-Forty-Five-Degree-Angle-One-Eighth-Inch-Male-PTF-Grease-Fitting.pdf) — web — Maker data sheet; numbers only
- Alemite: [Stainless steel grease fittings 1966-S, 1968-S, 1969-S (1/4-28 taper), 1961-S, 1921-S, 1922-S, 1923-S (1/8 PTF): hex, overall length, shank length](https://cdn.shopify.com/s/files/1/1425/8938/files/Alemite-1961S-StainlessSteel-Straight-Fitting-Grease-Zerk-Hydraulic-Corrosion-Resistant.pdf) — web — Maker data sheet; numbers only
- McMaster-Carr: [Grease fittings, 1/4-28 SAE-LT (hex, overall and thread length per fitting) (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/plugs/thread-type~sae-lt) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)
- AFT / Kipp K1132: [Grease nipples, conical head, DIN 71412 style A, straight: M6x1, M8x1, M8x1.25, M10x1, M10x1.5, R1/8, R1/4: D, L1, SW](https://www.aftfasteners.com/content/K1132-A-Datasheet-18495-Grease-nipples-conical-head-DIN-71412-style-A-straight-enUS.pdf) — web — Maker data sheet; numbers only. Letters are not defined on the sheet
- AFT / Kipp K1132: [Grease nipples, conical head, DIN 71412 style B, 45 deg: A, thread, L max, L1, SW](https://www.aftfasteners.com/content/K1132-B-Datasheet-18496-Grease-nipples-conical-head-DIN-71412-style-B-45-hexagonal-enUS.pdf) — web — Maker data sheet; numbers only. Letters are not defined on the sheet
- Bollhoff: [DIN 71412 C conical grease nipple (form C, 90 deg head position), steel 5.8 zinc-plated: thread, s, pitch, l, M6, M8, M10](https://eshop-tr.boellhoff.com/out/media/pdf/DIN_71412_C_Stahl_5.8_gv_M___en.pdf) — web — Maker data sheet; numbers only
- Wuerth: [Cone grease nipple form B (45 deg) DIN 71412, zinc-plated, M10x1: thread length 5.5, wrench size 11, overall length 25](https://eshop.wuerth.dk/Cone-grease-nipple-shape-B-angled-shape-45-DIN-71412-shape-B-zinc-plated-steel-with-hexagon-NPL-DIN71412-B-H2-A3F-WS11-HEX-M10X1/0986592.sku/en/US/DKK) — web — Maker shop page; numbers only

## Questions

**What hex size is a standard 1/4-28 zerk fitting?**

5/16 in for the straight ones (Alemite 1641-B etc., 35/64 to 1-5/8 in overall) and 3/8 in for the 45°, 65° and 90° ones.

**What size is an M10x1 grease nipple?**

DIN 71412: hex 11 mm for forms A and B (AFT / Kipp) and C (Bollhoff); form A overall L1 is 16 mm on the AFT sheet and form C l is 15.3 mm on Bollhoff's.

**What is the thread on a 1/8 grease fitting?**

1/8 PTF (Dryseal taper) on the Alemite sheets, with a 7/16 in hex for most types; DIN 71412 uses R1/8 (BSPT) with an 11 mm hex.

## Fits with

- [NPT pipe thread dimensions (ASME B1.20.1): TPI, E0, E1, L1, L2 and tap drill, NPS 1/8 to 6 + male NPT end STEP/STL](https://xemstudio.com/objects/npt-thread-dimensions-asme-b1-20-1/)
- [NPT male thread envelopes 1/8 to 1 in (ASME B1.20.1)](https://xemstudio.com/objects/npt-thread-envelopes/)
- [NPT pipe plugs: square head, hex head, round head and hex socket (ASME B16.11; Dryseal NPTF, flush PTF) 1/16 to 6 in — head size, length, socket + envelope models](https://xemstudio.com/objects/pipe-plugs-npt-square-hex-socket/)
- [AN and JIC 37° flare fittings: dash sizes -3 to -20, thread, tube OD, hose ID, flare diameter](https://xemstudio.com/objects/an-jic-37-degree-flare-fittings/)
- [Forged threaded fittings (ASME B16.11), Class 2000 / 3000 / 6000: elbows, tees, caps — centre-to-end, band OD, thread length](https://xemstudio.com/objects/forged-threaded-fittings-b16-11/)
- [Hex nuts, M2–M8 (ISO 4032)](https://xemstudio.com/objects/hex-nuts-metric/)
- [Hex keys (Allen keys): ISO 2936 metric 0.7–36 mm and ASME B18.3 inch .050–7/8 in: across flats, across corners, long and short arm + 31 key models](https://xemstudio.com/objects/hex-keys-iso-2936-asme-b18-3/)