DIN 125 Flat Washers (ISO 7089) — 304 & 316 Stainless
DIN 125 Form A is the standard metric flat washer for general bolted joints. We manufacture them at our Jiaxing factory in 304, 316 and 316L stainless steel, covering the full M2–M64 range in bright finish as standard and polished on request. Every production run is traceable to documented stainless melts; MTC (EN 10204 3.1) and PMI are available on request.
DIN 125 dimensions (Form A, nominal mm)
Nominal dimensions for DIN 125 Form A. The standard is dimensionally equivalent to ISO 7089 (plain) and ISO 7090 (chamfered). All values in millimetres.
| Thread size | Inner Ø d1 (mm) | Outer Ø d2 (mm) | Thickness s (mm) |
|---|---|---|---|
| M2 | 2.2 | 5 | 0.3 |
| M2.5 | 2.7 | 6 | 0.5 |
| M3 | 3.2 | 7 | 0.5 |
| M3.5 | 3.7 | 8 | 0.5 |
| M4 | 4.3 | 9 | 0.8 |
| M5 | 5.3 | 10 | 1.0 |
| M6 | 6.4 | 12 | 1.6 |
| M7 | 7.4 | 14 | 1.6 |
| M8 | 8.4 | 16 | 1.6 |
| M10 | 10.5 | 20 | 2.0 |
| M12 | 13 | 24 | 2.5 |
| M14 | 15 | 28 | 2.5 |
| M16 | 17 | 30 | 3.0 |
| M18 | 19 | 34 | 3.0 |
| M20 | 21 | 37 | 3.0 |
| M22 | 23 | 39 | 3.0 |
| M24 | 25 | 44 | 4.0 |
| M27 | 28 | 50 | 4.0 |
| M30 | 31 | 56 | 4.0 |
| M33 | 34 | 60 | 5.0 |
| M36 | 37 | 66 | 5.0 |
Larger sizes up to M64 available on request. Dimensions per DIN 125 Form A / ISO 7089 (nominal); tolerances per standard. Inch sizes also produced.
Made to product grade A.
All HUIHUI DIN 125 washers are produced to DIN 125 / ISO 7089, product grade A — the standard precision grade. Dimensional tolerances follow the standard:
| Dimension | Tolerance direction | Example (M8) |
|---|---|---|
| Inner Ø d1 | plus only (0 / +) | 8.4 → 8.62 mm |
| Outer Ø d2 | minus only (0 / −) | 16 → 15.57 mm |
| Thickness s | symmetrical (±) | 1.6 mm (1.4–1.8) |
The full per-size minimum/maximum table to DIN 125 / ISO 7089, plus a dimensional inspection report to your AQL, are supplied with the order on request — together with the material certificate (MTC, EN 10204 3.1) and PMI. Tighter tolerances on specific features can be held on custom parts; send your drawing.
DIN 125 vs DIN 9021 vs ISO 7089
Three related standards, three different use cases. Choosing the wrong one is the most common washer specification error.
DIN 125 — standard OD
Outside diameter roughly 2–2.5× the bolt diameter. The correct choice for standard clearance holes and general structural fastening. DIN 125 Form A (plain) was effectively superseded and aligned by ISO 7089 — dimensions are interchangeable for most applications. This is the part you want for everyday M-series bolted joints.
DIN 9021 — large OD (fender)
Outside diameter roughly 3× the bolt — significantly wider than DIN 125. Designed to spread clamping force across soft, slotted or oversized holes. Correct for thin sheet metal, plywood, rubber gaskets or any surface where a standard-OD washer would pull through or compress unevenly. See our fender washers →
ISO 7089 / 7090 — ISO equivalent
ISO 7089 is the plain-face version; ISO 7090 adds a chamfer on one face for countersunk applications. Both are dimensionally equivalent to DIN 125 Form A — if your drawing calls for ISO 7089, a DIN 125 A washer fits the same hole and bearing surface. For full standard reference tables, see our DIN & ISO reference.
Material: 304, 316 or 316L
Grade choice is set by the corrosion environment — not by surface finish or price alone. Here is the short version.
304 — the standard grade
18% chromium, 8% nickel. Excellent oxidation and general corrosion resistance. The right specification for indoor structural work, food-equipment assembly, architectural hardware and most non-aggressive outdoor environments. Cost-effective and widely stocked.
316 & 316L — for chloride exposure
Add 2–3% molybdenum to the 316 alloy and you get substantially better resistance to chloride pitting and crevice corrosion. Specify 316 for marine, coastal, chemical-process and de-icing environments. 316L (low-carbon) is the correct choice where welding is involved — the lower carbon content prevents sensitisation and intergranular attack at the weld heat-affected zone.
Bright (as-stamped mill finish) as standard — clean, consistent and practical for most industrial supply. Polished finish available on request for architectural, food-grade or visible-fastener applications. Finish is a surface detail; corrosion performance is determined by the grade.
How we make DIN 125 flat washers
Three things separate a washer that holds tolerance over a million-piece run from one that drifts after the first shift.
1. High-speed coil-fed pressing
We run JH21-series power presses fitted with automatic coil feeders — stainless strip feeds straight off the reel into the die at a controlled rate. No manual blank loading means no variation from operator to operator. Stroke rate and feed pitch are set once per die; the press holds them for the duration of the run. That is how you get M6 d₁ at 6.4 mm throughout 500,000 pieces, not just the first 10,000.
2. Genuine full-spec stainless
Material is sourced from documented stainless melts with traceable heat numbers. We stamp to the full nominal thickness specified in DIN 125 — not under-gauge strip to save cost. Recycled or mixed-grade material is not used. When we say 316L, the PMI will confirm it.
3. ISO 9001:2015 QC, MTC on request
Our quality management system is certified to ISO 9001:2015 (cert No. 74326Q00174R001). Inspection covers incoming coil verification, in-process dimensional checks at set intervals, and pre-shipment sampling. For export orders requiring compliance documentation:
- MTC (EN 10204 3.1) — mill test certificate tracing heat number, chemical composition and mechanical properties. Available on request at no extra charge for standard orders.
- PMI — positive material identification by XRF, confirming grade on finished parts. Available on request for critical or regulatory applications.
- First-article inspection — available for new tooling or non-standard sizes; dimensional report issued before bulk shipment.
Shipment terms FOB Ningbo or CIF to your port. HS code 7318.22.
DIN 125 questions, answered.
The specification questions engineers and procurement teams ask us most about DIN 125 flat washers. Have one we have not covered? Ask our team.
What is a DIN 125 washer?
DIN 125 is the German standard for the regular-series flat washer. It specifies an inner bore slightly larger than the nominal bolt diameter, a round outside diameter roughly 2–2.5× the bolt, and a defined thickness. DIN 125 Form A is the plain (un-chamfered) version and is dimensionally equivalent to ISO 7089. It is the default general-purpose metric flat washer used in most bolted joint applications across construction, machinery and equipment.
What sizes (M-range) do you make in DIN 125?
We run the full range from M2 through to M64 in 304, 316 and 316L. The table on this page lists all standard nominal sizes from M2 to M36 with exact DIN 125 Form A dimensions. Sizes from M39 to M64 are available on request — state the size and quantity in your inquiry and we will come back with pricing and lead time within one business day.
Should I specify 304 or 316 for DIN 125 flat washers?
304 (A2) covers general indoor, structural and most non-aggressive outdoor use. 316 or 316L (A4) is the correct specification when chloride exposure, salt spray, marine environment or chemical contact is involved — the added molybdenum resists pitting corrosion that attacks 304 in those conditions. 316L is the low-carbon variant; specify it when washers are used in welded assemblies to prevent sensitisation. If you are unsure, read the full grade comparison or ask us — we will confirm the right grade for your application.
What is the difference between DIN 125 and DIN 9021?
DIN 125 is the standard-OD flat washer, with an outside diameter 2–2.5× the bolt — correct for standard clearance holes and solid bearing surfaces. DIN 9021 is the fender (large-OD) washer, with an outside diameter about 3× the bolt — designed for soft, slotted or oversized holes where you need to spread load over a larger area. Same bolt-hole size, very different footprint. If the hole is larger than standard, or the substrate is soft, you want DIN 9021. See our DIN 9021 fender washers →
Do you provide MTC / PMI, and what are the shipping terms?
Yes. Mill test certificates (MTC, EN 10204 3.1) confirming heat number, chemistry and mechanical properties are available on request — standard for export orders. PMI by XRF can be arranged for compliance-critical shipments. We ship FOB Ningbo or CIF to your named port; HS code 7318.22. MOQ and lead time are flexible and confirmed with your quote — no fixed minimum to ask. Send specs and quantities and we reply within one business day.
Tell us what you need.
Send specs or a drawing and we will come back with pricing, lead time and material options. No account, no minimum to ask.
- ✓ 304 / 316 / 316L, DIN 125 Form A or custom
- ✓ Replies from engineers, typically within one business day
- ✓ MTC (EN 10204 3.1) and PMI available on request
- ✓ FOB Ningbo / CIF · HS 7318.22