ISO 8738 Washers for Pins
ISO 8738 medium-type plain washers for parallel and taper pins — d1 H11 from 3 to 100 following the pin-diameter series, with the collected d2/s ladder and kg/1000 weights.
Last updated: 2026-11
Specifications
ISO 8738 is the washer matched to pinned joints rather than bolted ones: its bore follows the pin-diameter series (3 to 100, including the intermediate pin sizes 7, 13, 23, 26, 27) with an H11 tolerance band, and its outside diameter and thickness sit between the ISO 7092 small series and the normal series — hence "medium type" in the source heading. Under a pin or a clevis pin retained by a cotter, the washer spreads the axial play and the retaining load without the width a bolt washer would add. The collected ladder carries one row per pin diameter with a single d2 and s value (no min/max split — the source prints 6×0,8 at d1 3 up to 125×14 at d1 100) plus a kg/1000 weight. Because the ladder steps through the pin series rather than a thread series, weights are not monotone between neighbouring rows that share an outside diameter (the flagged 26/27 and 35/36 pairs) — read the row that matches your pin, not the neighbour's. The "For thread" column is the source's cross-reference to the nearest thread nominal. Pair this page with the parallel (ISO 2338/8734-class) and grooved (ISO 8741) pin pages in this catalog. Material and finish are not tabulated by the collected specification — per RFQ.
| Standard | ISO 8738 — plain washers, medium type, for pins |
|---|---|
| Size range | d1 H11: 3 – 100 in the pin-diameter series (38 sizes tabulated, including intermediates 7, 13, 23, 25, 26, 27, 28, 33, 35) |
| Hole diameter | d1, tolerance H11 per the source heading; single value per size |
| Outside diameter | d2: single value per size (6 → 125 mm) |
| Thickness | s: single value per size (0,8 → 14 mm) |
| Weight | kg/1000 pcs column carried verbatim (0,13 → 472) |
| Material / finish | Not tabulated by the collected specification — per RFQ |
| d1 H11 | For thread | d2 | s | Weight kg/1000pcs |
|---|---|---|---|---|
| 3 | M3 | 6 | 0,8 | 0,13 |
| 4 | M4 | 8 | 0,8 | 0,23 |
| 5 | M5 | 10 | 0,8 | 0,36 |
| 6 | M6 | 12 | 1,6 | 1,05 |
| 7 | M7 | 14 | 1,6 | 1,42 |
| 8 | M8 | 16 | 2 | 2,22 |
| 10 | M10 | 20 | 2,5 | 4,56 |
| 12 | M12 | 25 | 3 | 8,99 |
| 13 | M13 | 25 | 3 | 8,36 |
| 14 | M14 | 28 | 3 | 10,8 |
| 16 | M16 | 28 | 3 | 9,68 |
| 18 | M18 | 30 | 4 | 13,8 |
| 20 | M20 | 32 | 4 | 15 |
| 22 | M22 | 34 | 4 | 16,2 |
| 23 | M23 | 36 | 4 | 18,5 |
| 24 | M24 | 38 | 4 | 21,4 |
| 25 | M25 | 40 | 4 | 23,6 |
| 26 | M26 | 40 | 5 | 28,5 |
| 27 | M27 | 40 | 5 | 26,5 |
| 28 | M28 | 42 | 5 | 29,7 |
| 30 | M30 | 45 | 5 | 34,2 |
| 32 | M32 | 50 | 5 | 44,8 |
| 33 | M33 | 50 | 5 | 43,3 |
| 35 | M35 | 52 | 6 | 52,8 |
| 36 | M36 | 52 | 6 | 49,5 |
| 40 | M40 | 58 | 6 | 63,7 |
| 45 | M45 | 62 | 7 | 76,8 |
| 50 | M50 | 68 | 8 | 101 |
| 55 | M55 | 75 | 9 | 141 |
| 60 | M60 | 80 | 9 | 151 |
| 65 | M65 | 90 | 9 | 211 |
| 70 | M70 | 95 | 10 | 250 |
| 75 | M75 | 100 | 10 | 265 |
| 80 | M80 | 110 | 12 | 413 |
| 85 | M85 | 110 | 12 | 371 |
| 90 | M90 | 115 | 12 | 370 |
| 95 | M95 | 120 | 12 | 387 |
| 100 | M100 | 125 | 14 | 472 |
- Row 19 (27): d1 26 → 27 (both d2 = 40): weight prints 28,5 then 26,5 — non-monotone against the ascending d1. Carried verbatim, not normalized.
- Row 25 (36): d1 35 → 36 (both d2 = 52): weight prints 52,8 then 49,5 — non-monotone against the ascending d1. Carried verbatim, not normalized.
Materials
- Material and finish specified per RFQ — pinned joints in machinery commonly take hardened or plain steel washers; state the duty at quotation
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (ISO 8738 Washers for Pins) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Why does this washer ladder step through sizes like 7, 13 and 23 that no bolt thread uses?
Because it is keyed to pins, not threads. Parallel and taper pin diameters come in a finer series than bolt nominals — a d1 13 washer sits under a 13 mm clevis pin, not a "M13" bolt, and the 7 mm bore pairs with the pin between the 6 and 8 mm steps. That also explains the two flagged weight pairs (26/27 and 35/36, where equal outside diameters print non-monotone masses): neighbouring rows are different pins in the same ring size, and the source's kg/1000 values are carried verbatim. The practical takeaway: order by your pin's actual diameter against the d1 H11 column, and use the "For thread" column only as a rough cross-reference. The pin pages themselves (parallel dowel, grooved, taper) carry the pin-side geometry; washer material and finish stay per RFQ.
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support