GB/T 1222-2025 spring steel · order-specific technical review
65Mn is a Chinese manganese spring-steel designation covered by GB/T 1222. It is commonly considered for springs and wear-resistant parts after a suitable forming and heat-treatment route. Grade name alone does not define strip condition, hardness, dimensions, tolerances or suitability for a finished component.
As of 14 August 2026, the current national-standard catalogue lists GB/T 1222-2025 as effective from 1 May 2026. Purchase documents should identify the required standard edition.
| RFQ field | Required decision |
|---|---|
| Grade and standard | State 65Mn and the governing GB/T 1222 edition, or attach the buyer specification. |
| Dimensions | State nominal thickness, width and each tolerance together. Portfolio limits are not a promise for every combination. |
| Delivery condition | Cold rolled, annealed, or an agreed hardened-and-tempered condition. |
| Edge and surface | State slit/deburred/rounded edge and the surface requirement or reference sample. |
| Acceptance | Define hardness or tensile requirement, test method, sampling, documents and application. |
Numerical composition and mechanical-property limits must be taken from the edition named in the purchase specification. Hengtaifeng does not treat a generic web table as an order guarantee. The agreed material certificate, test method and acceptance criteria control the supplied order.
| Designation sometimes compared | Safe procurement interpretation |
|---|---|
| AISI/SAE 1065 | A candidate comparison based partly on carbon level; manganese limits and product requirements can differ. |
| JIS SUP6 | Not a direct substitute: it is a silicon-manganese spring-steel designation with different chemistry. |
| EN/DIN references such as C67S / 1.1231 | Candidate references only; check chemistry, product standard, delivery condition and testing before approval. |
Decision rule: never replace 65Mn from a cross-reference table alone. Compare the complete standards and obtain engineering approval.
Flat springs, clips, washers and related parts where the buyer validates forming, heat treatment and fatigue performance.
Selected blades and wear components where the complete geometry, toughness and hardness requirements are reviewed together.
Parts produced from annealed or cold-rolled strip before an agreed downstream or in-house heat-treatment route.
Page reviewed: 2026-08-25. Sources establish standards and test-method context; they do not certify a specific Hengtaifeng order.
Compare 65Mn vs 51CrV4, review hardened and tempered strip, use our spring steel selection guide, or check the steel strip RFQ checklist.
51CrV4 (alloy spring) · SK5 (high carbon) · S50C (medium carbon)