Spring steel that compresses 10,000 times without taking a set, circlip steel that snaps into a groove and holds, and low-carbon steel that blanks into a million washers — with HRC 42–50, elastic limit ≥800 MPa, and surface treatment ready for black oxide, zinc or dacromet.
An elastic washer must compress and spring back. A circlip must expand and lock. A flat washer must distribute load. A bracket must form and hold. Each function demands a different steel: one with high elastic limit, one that snaps and holds, one that is soft and formable, one that resists corrosion. The four families below map directly to those four functions.
C 0.62–0.72%, Mn 0.60–1.20%. The standard elastic fastener steel: quenches and tempers to 42–50 HRC with elastic limit ≥800 MPa, allowing an elastic washer to compress under bolt load and spring back through 10,000+ cycles. Circlips run 44–52 HRC for the snap-in force needed to lock into a groove. Supplied spheroidized-annealed for blanking, with controlled decarb so the working surface is not a soft skin.
Choose 65Mn/C67S for every elastic washer, circlip and high-cycle spring fastener.C 0.65–0.80% (SAE1070) or C 0.80–0.90% (SK5). Higher carbon than 65Mn for greater hardness and wear resistance, reaching HRC 35–45 after quenching and tempering. Used for flat washers that need some hardness, shims that must resist indentation, and spring clips that require high strength without the full elastic performance of spring steel. SAE1070 is the AISI standard; SK5 is the JIS equivalent.
Choose SAE1070/SK5 for flat washers, shims and spring clips where hardness matters.C ≤0.12%, cold-rolled to 0.3–3.0 mm. SPCC is non-alloy, low-cost, and highly formable — the standard for flat washers, general hardware stampings, hinges, brackets and structural clips. It blanks cleanly at high speed, takes zinc plating or black oxide readily, and provides the surface quality for cosmetic hardware. SPCC is the default when the fastener does not need spring function or high hardness.
Choose SPCC for flat washers, brackets, hinges and general hardware stampings.C ≤0.15%, Cr 16–18%, Ni 6–8%. Austenitic stainless that work-hardens during forming, reaching 800–1200 MPa in H temper. Used for elastic washers, circlips and spring clips in corrosive environments — outdoor hardware, marine, food processing — where carbon steel would rust. SUS301 does not quench-harden, so its elastic performance comes from cold work rather than heat treatment.
Choose SUS301 for stainless elastic fasteners in moist, outdoor or corrosive environments.Indicative values from production fastener programs; the final spec is agreed at RFQ against your part drawing, fastener standard (GB, DIN, JIS, ASTM) and corrosion environment.
| Component | Steel grade | Thickness | Key parameter |
|---|---|---|---|
| Elastic washer (split lock) | 65Mn / C67S | 0.3 – 3.0 mm | HRC 42–50, elastic limit ≥800 MPa, 10k+ cycles |
| Circlip / retaining ring (external) | C67S | 0.4 – 2.0 mm | HRC 44–52, snap-in force, no permanent set |
| Circlip / retaining ring (internal) | 65Mn | 0.4 – 2.0 mm | HRC 44–52, groove lock, fatigue-resistant |
| Flat washer (hardened) | SAE1070 / SK5 | 0.5 – 3.0 mm | HRC 35–45, indentation-resistant, ID 3–50 mm |
| Flat washer (general) | SPCC | 0.3 – 3.0 mm | Formable, zinc-plated, ID 3–50 mm |
| Spring clip / tube clamp | 65Mn / SAE1070 | 0.5 – 2.5 mm | HRC 40–48, clamping force, fatigue-resistant |
| Hinge /合页 | SPCC / SAE1070 | 1.0 – 3.0 mm | Formable, weldable, wear-resistant pin hole |
| Stainless elastic washer | SUS301 H | 0.3 – 2.0 mm | Tensile 800–1200 MPa, corrosion-resistant |
Hardness values are after quenching and tempering for carbon and spring steels; SUS301 hardness is from cold work (temper designation). Elastic washer opening gap is 0.5–2.0 mm depending on size and standard. Surface treatment (black oxide, zinc, dacromet) is applied by the fastener maker after blanking and heat treatment.
All grades supplied with confirmed chemistry and mechanicals per heat. Choose by fastener function (elastic, hardened, general, stainless), corrosion environment and governing standard.
| Part type | Primary grade | Alternative grade | Selection criterion |
|---|---|---|---|
| Elastic / split lock washer | 65Mn (GB) | C67S (EN) | HRC 42–50 + elastic limit ≥800 MPa + 10k cycles |
| Heavy-duty elastic washer | C67S | C75S (EN) | Higher hardness + thicker section + heavy load |
| External circlip / snap ring | C67S | 65Mn | HRC 44–52 + snap-in force + no permanent set |
| Internal circlip / retaining ring | 65Mn | C67S | HRC 44–52 + groove lock + fatigue resistance |
| E-clip / shaft retaining ring | 65Mn | SUS301 (stainless) | Thin section + spring-back + corrosion option |
| Hardened flat washer | SAE1070 | SK5 (JIS) | HRC 35–45 + indentation resistance + cost |
| General flat washer / shim | SPCC | SPCD (deep draw) | Formability + plating + cost for high-volume |
| Spring clip / hose clamp | 65Mn | SAE1070 | Clamping force + fatigue + cost balance |
| Hinge /合页 leaf | SPCC | SAE1070 (hardened) | Formability + weldability + pin hole wear |
| Hardware bracket / stamping | SPCC | SPHC (hot rolled) | Thickness + formability + surface finish |
| Stainless elastic fastener | SUS301 H | SUS304 (general) | Corrosion resistance + spring-back + outdoor use |
Grade selection for elastic fasteners is driven by the required HRC band and cycle life. For stainless fasteners, SUS301 H is specified for elastic function; SUS304 is used for general (non-elastic) stainless hardware. Confirm the governing standard (GB/T 94.1, DIN 127, DIN 471, JIS B1251, ASTM F436) at RFQ — the standard defines dimensions, hardness and testing requirements.
These are the failure modes that show up in fastener production, in the order fastener engineers care about them.
An elastic washer that takes a permanent set after a few hundred compressions has insufficient hardness (below HRC 42) or a decarburized surface that reduces the elastic limit. Fix: 65Mn/C67S strip with confirmed hardenability per heat, quenched and tempered to the 42–50 HRC band, with decarb ≤0.03 mm per side. We report hardness and decarb on process samples with every MTC so the washer reaches its 10,000-cycle rating.
A circlip that fractures at the lug during installation has a surface defect from blanking or a hardness that is too high (above HRC 52), making the ring brittle. Fix: C67S/65Mn strip with controlled hardness in the 44–52 HRC band, clean shear edges from precision blanking, and a confirmed bend radius at the lug. We confirm the strip's ductility and hardness per coil so the circlip installs without fracture and locks into the groove.
A zinc-plated washer that develops blisters or poor coverage has residual oil, oxide or surface defects on the incoming strip. Fix: SPCC or spring steel strip with a clean, properly oiled surface, confirmed per coil. For high-volume fastener production, we can supply dry (oil-free) strip for in-line plating processes. The surface must be defect-free at the 5–15 μm zinc plating level for uniform coverage and corrosion resistance.
A flat washer that indents under bolt head load has insufficient hardness for the application. Fix: SAE1070 or SK5 strip hardened to HRC 35–45 for hardened flat washers, or SPCC for general-purpose washers where indentation is acceptable. We confirm the delivered hardness per coil and can supply pre-hardened strip for thin-gauge washers where through-hardening after blanking is difficult.
Fastener production draws on several steel families. Match your part below and confirm at RFQ.
65Mn / C67S / C75S spring steel for elastic washers, circlips and spring clips at HRC 42–52 with high elastic limit and fatigue resistance. Spring steel family →
SAE1070 / SK5 / SAE1078 high-carbon steel for hardened flat washers, shims and spring clips where hardness and wear resistance are required. High carbon family →
SPCC / SPCD low-carbon cold-rolled strip for flat washers, brackets, hinges and general hardware stampings with formability and plating-ready surface. Cold-rolled family →
SUS301 / SUS304 stainless for corrosion-resistant elastic washers, circlips and hardware in outdoor, marine and food environments. Stainless steel family →
A typical M10 split lock washer (DIN 127B), described the way it runs.
The washer is an M10 split lock washer to DIN 127B, 10.2 mm inner diameter, 20 mm outer diameter, 2.0 mm thick, with a 1.2 mm opening gap and square ends. The drawing calls 65Mn spring steel strip, 2.0 mm, spheroidized-annealed, decarb ≤0.03 mm per side. The strip is blanked to the washer profile in a high-speed progressive die at 600 strokes per minute, then the washers are quenched at 820–850 °C, tempered at 400–430 °C to land 44–48 HRC, and then zinc-plated with trivalent chromate passivation to 8–10 μm. Every batch is tested for hardness (Rockwell C on the washer face), elastic performance (compressed to solid height three times, then checked for permanent set), and corrosion resistance (96 hours salt spray per ISO 9227).
The elastic set test is the moment of truth. The washer is compressed to its solid height (the gap fully closed) three times, then measured for permanent deformation of the opening gap. A washer that loses more than 10% of its gap height fails — and the root cause is almost always incoming strip hardness below spec or decarburization at the surface that reduces the elastic limit. That is why the 65Mn strip's hardenability and decarb limit are not optional: they are the difference between a 99% first-pass set test and a 75% pass rate with rework. Our job is to make the strip's chemistry, hardness and decarb so repeatable that the washer line's variables (blanking, quench temperature, tempering time) are the only variables left.
The same fastener factory produces C67S external circlips, 1.0 mm thick, for a 20 mm shaft groove, hardened to 46–50 HRC and black-oxide finished. The circlip must expand over the shaft end and snap into the groove without fracture, then hold a 500 N axial load. And it produces SPCC flat washers, 1.5 mm thick, M8 size, zinc-plated for general hardware distribution. If your fastener program needs 65Mn for elastic washers, C67S for circlips, SAE1070 for hardened flat washers, SPCC for general stampings, or SUS301 for stainless elastic parts, send the drawing and we confirm grade, hardness, surface condition and a trial-coil plan. Our slitting and processing services cover exact-width coils, cut-to-length sheets and edge conditioning for high-speed blanking.
Related reading: how 65Mn, SAE1070 and C67S compare for spring and fastener applications, and spring steel standards across GB, EN, JIS and AISI. For procurement context, see our precision steel strip buyer's handbook. Related application pages: spring steel for clutch disc springs and home appliance components steel.
These grade families share material, processing or application territory with the topic on this page.
65Mn / C67S / C75S grades with HRC 42–52 and elastic limit ≥800 MPa for spring fasteners.
SAE1070 / SK5 / SAE1078 grades at HRC 35–45 for flat washers and spring clips.
SPCC / SPCD grades with formability and plating-ready surface for general hardware.
Send part drawing, thickness × ID, target HRC, surface treatment, quantity and destination port. Our engineers reply within one working day with grade match and a trial-coil option.