Technically reviewed by Vincent, Founder at HEXVARO
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Sourcing these sizes? DIN 127 B spring lock washers Industrial washer supplier
DIN 127 B spring washer dimensions (mm)
d1 is the minimum inner diameter, d2 the maximum outer diameter, b × s the section (width × thickness) and h the free height range of the uncompressed washer. Weight is for spring steel.
| Size | Inner d1 min | Outer d2 max | Section b × s | Free height h | Weight (kg / 1000) | Inquiry |
|---|---|---|---|---|---|---|
| M4 | 4.1 | 7.6 | 1.5 × 0.9 | 1.8–2.1 | 0.18 | Quote this size |
| M5 | 5.1 | 9.2 | 1.8 × 1.2 | 2.4–2.8 | 0.36 | Quote this size |
| M6 | 6.1 | 11.8 | 2.5 × 1.6 | 3.2–3.8 | 0.83 | Quote this size |
| M8 | 8.1 | 14.8 | 3 × 2 | 4.0–4.7 | 1.6 | Quote this size |
| M10 | 10.2 | 18.1 | 3.5 × 2.2 | 4.4–5.2 | 2.53 | Quote this size |
| M12 | 12.2 | 21.1 | 4 × 2.5 | 5.0–5.9 | 3.82 | Quote this size |
| M14 | 14.2 | 24.1 | 4.5 × 3 | 6.0–7.1 | 6.01 | Quote this size |
| M16 | 16.2 | 27.4 | 5 × 3.5 | 7.0–8.3 | 8.91 | Quote this size |
| M18 | 18.2 | 29.4 | 5 × 3.5 | 7.0–8.3 | 9.73 | Quote this size |
| M20 | 20.2 | 33.6 | 6 × 4 | 8.0–9.4 | 15.2 | Quote this size |
| M22 | 22.5 | 35.9 | 6 × 4 | 8.0–9.4 | 16.5 | Quote this size |
| M24 | 24.5 | 40 | 7 × 5 | 10.0–11.8 | 26.2 | Quote this size |
Form A vs form B
Form A has tanged ends that are bent up to dig into the nut and the joint surface. Form B has flat (square) ends and is by far the most common in trade and distribution. When an order says simply "DIN 127", most suppliers assume form B; state the form to be sure.
Why DIN 127 was withdrawn
DIN 127 has been withdrawn without a direct replacement. Vibration testing going back to Junker's work in 1969 showed that helical spring washers do not stop self-loosening and can even speed it up. With property class 8.8 bolts and above, the washer is pressed flat at roughly 10–20 % of the target preload, so it adds nothing once the joint is properly tightened. Standards bodies withdrew these washer standards to discourage designers from specifying them.
Spring washers are still widely used for low-strength bolts, sheet metal, electrical connections and replacement parts, which is why they remain a high-volume item. For new structural or machinery designs, specify a locking method that has been shown to work.
Better alternatives for vibration locking
| Method | Standard examples | Notes | Inquiry |
|---|---|---|---|
| Correct preload | Bolt class 8.8 / 10.9 tightened to specification | Adequate preload is the most effective protection against loosening | Quote this size |
| Nylon insert lock nut | DIN 985 / ISO 10511, DIN 982 / ISO 7040 | Prevailing torque; limited to about 120 °C | Quote this size |
| All-metal prevailing torque nut | DIN 980 / ISO 7042 | High-temperature service | Quote this size |
| Wedge-locking washer pair | Supplier-specific designs | Tested to resist loosening under vibration | Quote this size |
| Serrated flange bolt and nut | DIN 6921 / DIN 6923 | No separate washer; marks the clamped surface | Quote this size |
| Thread-locking adhesive | Anaerobic adhesive | Permanent or removable grades | Quote this size |
Materials and finishes
- Spring steel, hardened and tempered, plain or black for oiled machinery parts.
- Zinc plated: hardened spring washers carry a risk of hydrogen embrittlement after electroplating. Ask for baking after plating, or choose mechanical zinc or zinc flake.
- Stainless A2 and A4 for corrosive environments and with stainless bolts.
- If the bolts are hot-dip galvanized, confirm the washer finish with the designer; a thin zinc-plated washer will corrode first.
How to specify spring washers in your RFQ
- Standard and form: DIN 127 A (tanged ends) or DIN 127 B (flat ends), or a drawing.
- Bolt size and any special inner diameter or section.
- Material: spring steel, or stainless A2 / A4.
- Finish: plain, black, zinc plated with baking, mechanical zinc or zinc flake.
- Quantity per size and packaging (bags, boxes or bulk).
Order these sizes from HEXVARO
Send your size list with grade, finish and quantity — we reply within 2 working hours with price, lead time and shipping terms.
- Reply: within 2 working hours
- MOQ: 500 pcs per specification
- Lead time: 10–15 days stock items
- Payment: T/T · L/C · PayPal
- Shipping ports: Tianjin · Ningbo · Shanghai · Shenzhen
- Incoterms: EXW · FOB · CFR · CIF · DAP
- Experience: Founder with 10+ years in the fastener industry
Frequently asked questions
What is the difference between DIN 127 A and B?
Form A has tanged (bent) ends and form B has flat ends. Form B is the most common in trade and distribution.
Is DIN 127 still a valid standard?
DIN 127 has been withdrawn without a direct replacement, but it remains the common trade reference and is still widely produced and ordered.
Do spring washers prevent bolts from loosening?
Vibration testing shows they do not reliably prevent self-loosening, and with 8.8 bolts and above they flatten at a small fraction of the preload. Use correct preload and a proven locking method instead.
Should spring washers be electroplated?
Hardened spring washers carry a risk of hydrogen embrittlement after electroplating. Ask for baking after plating or use mechanical zinc, zinc flake or stainless.
How much does an M10 spring washer weigh?
About 2.5 g, or 2.53 kg per 1,000 pieces for DIN 127 form B.
What is the MOQ for spring washers?
Reference MOQ is 500 pcs per specification. Stock sizes typically ship in 10–15 days and made-to-order sizes in 25–30 days, subject to quotation. We reply to every RFQ within 2 working hours.
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