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Nylon washers and EPDM / neoprene flat sealing washers: M2–M12 sizes from two nylon makers, rubber washer sizes and what the standards say
What size are nylon washers and EPDM or neoprene sealing washers for M4, M5, M6, M8, M10 and M12 screws? · Standard part · basis: Jetpress's DIN 125 nylon table, an RS Components nylon 6,6 datasheet and Aspen Fasteners' M12 sheet (nylon); Polymax's EPDM solid-washer list (rubber); mm; 8 envelope files for sizes where the makers agree
Also called: m6 nylon washer dimensions, m8 nylon washer outside diameter, m5 nylon washer thickness, epdm sealing washer m6, m10 rubber washer size, m4 rubber washer 9 mm, nylon washer m12 24 mm, m3 nylon washer od, neoprene washer m8, nylon washer thickness chart, rubber sealing washer for screws, plastic washer m5
Exact dimensions. Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part. Mating features
- length
- 24.0 mm
- width
- 24.0 mm
- height
- 2.5 mm
Notes
- Nylon (polyamide) flat washers follow the DIN 125 form A pattern, but they are described by the makers as 'similar to' it (Westfield). The two tables read here agree for M2, M2.5, M4 and M12 and differ for M3 (OD 7 against 8 mm), M5 (10 against 11), M6 (12.5 × 1.6 against 12 × 1.5), M8 (17 × 1.6 against 18 × 2) and M10 (21 × 2 against 22 × 2.5). Both are shown; the files are drawn only where they agree. Aspen's M12 sheet (DIN 125 Type A / ISO 7089, nylon 6/6) matches 13 × 24 × 2.5 mm and prints the tolerances (ID 13 to 13.27, OD 23.48 to 24, T 2.3 to 2.7).
- Rubber sealing washers (EPDM, neoprene, silicone) are plain flat rings, and no ISO or DIN dimension standard for them was found. Polymax's EPDM list (black, 60 ShA) shows that the same label covers several sizes: 'M6' is 6.4 × 14, 6.4 × 12.5 or 6 × 22 mm, and 'M8' is 8 × 20, 8 × 24 or 8.5 × 17 mm, all 1.5 mm thick. Four of them are drawn (M4 4 × 9, M5 5.3 × 10, M6 6.4 × 12.5, M8 8.5 × 17) as examples; the label is the maker's. A neoprene flat-washer list (Superior Washer, inch sizes) was read, but it printed no screw size, no durometer and no units, so it is not used.
- Bonded (metal-and-rubber) sealing washers are a separate part: see iso-1179-bspp-ports-and-bonded-seals for the bonded seal sizes. McMaster-Carr lists EPDM and neoprene sealing washers for screw sizes No. 2 to 1-1/4 in and M3 to M30 (its filters; no per-part rows were read), with per-part STEP on its own site.
- Not tabled: neoprene or silicone sizes, shore hardness other than the 60 ShA Polymax lists, and FDA grades. Files are plain annuli at the printed ID, OD and thickness.
Nylon washers and EPDM / neoprene flat sealing washers: M2–M12 sizes… size chart
| washer | size | ID × OD × T (mm): Jetpress / Polymax | ID × OD × T (mm): RS datasheet | makers |
|---|---|---|---|---|
| nylon flat washer | M2 | 2.2 × 5 × 0.3 | 2.2 × 5 × 0.3 | agree |
| nylon flat washer | M2.5 | 2.7 × 6 × 0.5 | 2.7 × 6 × 0.5 | agree |
| nylon flat washer | M3 | 3.2 × 7 × 0.5 | 3.2 × 8 × 0.8 | differ |
| nylon flat washer | M4 | 4.3 × 9 × 0.8 | 4.3 × 9 × 0.8 | agree |
| nylon flat washer | M5 | 5.3 × 10 × 1 | 5.3 × 11 × 1 | differ |
| nylon flat washer | M6 | 6.4 × 12.5 × 1.6 | 6.4 × 12 × 1.5 | differ |
| nylon flat washer | M8 | 8.4 × 17 × 1.6 | 8.4 × 18 × 2 | differ |
| nylon flat washer | M10 | 10.5 × 21 × 2 | 10.5 × 22 × 2.5 | differ |
| nylon flat washer | M12 | 13 × 24 × 2.5 | 13 × 24 × 2.5 | agree |
| EPDM flat washer (Polymax) | M4 | 4 × 9 × 1.5 | – | one maker |
| EPDM flat washer (Polymax) | M5 | 5.3 × 10 × 1.5 | – | one maker |
| EPDM flat washer (Polymax) | M6 | 6.4 × 12.5 × 1.5 | – | one maker |
| EPDM flat washer (Polymax) | M8 | 8.5 × 17 × 1.5 | – | one maker |
| nylon M12 (Aspen, DIN 125A / ISO 7089) | M12 | 13 × 24 × 2.5; ID 13 to 13.27, OD 23.48 to 24, T 2.3 to 2.7 | – | tolerances |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| bore | nylon: Ø2.2 (M2), 2.7 (M2.5), 4.3 (M4), 13 (M12) mm; EPDM: Ø4 (M4), 5.3 (M5), 6.4 (M6), 8.5 (M8) mm | screw of the named size; nylon bores are the DIN 125 form A clearance values (flat-washers-metric) | slide | nylon-washer-* |
| bore | EPDM Ø4.0 / 5.3 / 6.4 / 8.5 mm | screw of the labelled size; the washer is soft and seals by compression | slide | epdm-washer-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Jetpress (maker) | Nylon washer, standard, DIN 125: M2 to M20 ID (D1), OD (D2), thickness (T), mm | web | Publisher's page; dimensions are facts |
| RS Components (datasheet) | Nylon 6,6 washers, natural: M2 to M12 I/D, O/D, thickness (standard not named on the sheet) | web | Publisher's page; dimensions are facts |
| Aspen Fasteners | M12 DIN 125 Type A / ISO 7089 nylon 6/6 washer: ID 13 (13 to 13.27), OD 24 (23.48 to 24), thickness 2.5 (2.3 to 2.7) | web | Publisher's page; dimensions are facts |
| Polymax (maker), EPDM solid washers | EPDM solid washers, black, 60 ShA: ID x OD x thickness, as printed (no standard stated; 28 of 99 items read) | web | Publisher's page; dimensions are facts |
| McMaster-Carr | EPDM rubber sealing washers (screw sizes No. 2 to 1-1/4 in and M3 to M30 listed as filters; no per-part rows read) (free STEP per part, for your own design use; no redistribution) | STEP, IGES, PDF | McMaster-Carr site terms: personal design use, no redistribution verify |
Free files
★ Free files 8 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| nylon-washer-m2 | nylon flat washer for M2: plain annulus Ø2.2 inside, Ø5 outside, 0.3 mm thick (Jetpress DIN 125 and RS datasheet agree) | STEP · STL |
| nylon-washer-m2p5 | nylon flat washer for M2.5: plain annulus Ø2.7 inside, Ø6 outside, 0.5 mm thick (Jetpress DIN 125 and RS datasheet agree) | STEP · STL |
| nylon-washer-m4 | nylon flat washer for M4: plain annulus Ø4.3 inside, Ø9 outside, 0.8 mm thick (Jetpress DIN 125 and RS datasheet agree) | STEP · STL |
| nylon-washer-m12 | nylon flat washer for M12: plain annulus Ø13 inside, Ø24 outside, 2.5 mm thick (Jetpress DIN 125 and RS datasheet agree) | STEP · STL |
| epdm-washer-m4-4p0x9p0 | EPDM flat sealing washer labelled M4 by the maker: plain annulus Ø4 inside, Ø9 outside, 1.5 mm thick (Polymax listing; no standard exists for these sizes) | STEP · STL |
| epdm-washer-m5-5p3x10p0 | EPDM flat sealing washer labelled M5 by the maker: plain annulus Ø5.3 inside, Ø10 outside, 1.5 mm thick (Polymax listing; no standard exists for these sizes) | STEP · STL |
| epdm-washer-m6-6p4x12p5 | EPDM flat sealing washer labelled M6 by the maker: plain annulus Ø6.4 inside, Ø12.5 outside, 1.5 mm thick (Polymax listing; no standard exists for these sizes) | STEP · STL |
| epdm-washer-m8-8p5x17p0 | EPDM flat sealing washer labelled M8 by the maker: plain annulus Ø8.5 inside, Ø17 outside, 1.5 mm thick (Polymax listing; no standard exists for these sizes) | STEP · STL |
https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.Plain text: sheet.txt · JSON: /api/geometry?object=nylon-and-rubber-sealing-washers
Fits with
Questions
What is the OD of an M6 nylon washer?
12.5 mm × 1.6 mm thick in Jetpress's DIN 125 nylon table; 12 mm × 1.5 mm in an RS Components nylon 6,6 datasheet. The two makers differ.
What size is an M12 nylon washer?
13 mm ID × 24 mm OD × 2.5 mm thick; both nylon tables read agree, and Aspen's sheet gives the tolerances.
Is there a standard size for EPDM sealing washers?
No standard was found; makers list their own sizes. One maker's 1.5 mm EPDM washers labelled M6 come as 6.4 × 12.5 and 6.4 × 14 mm, among others.