MATERIAL INTRODUCTION
SK7 Steel Strip
Carbon tool steel strip, magnetic, density: 7.85 g/cm³.
- Grade
- SK7
- Thickness
- 0.08–3.0 mm
- Width
- 2 mm
Chemical Composition (wt%)
| C | Si | Mn | P | S | Cr | Ni | Cu |
|---|---|---|---|---|---|---|---|
| 0.60～0.70 | 0.10～0.35 | 0.10～0.50 | ≤0.030 | ≤0.030 | ≤0.25 | ≤0.25 | ≤0.30 |
Applicable Standards
| Standard / Designation |
|---|
| JIS G4401 |
| equivalent to GB T7A |
| German C70W2 |
Tempers & Hardness
| Temper | Hardness / Characteristics |
|---|---|
| ANN (Annealed, Soft Temper) | HV ≤210, good ductility for bending & stamping before heat treatment |
| 1/4H | 230–270 HV |
| 1/2H | 270–320 HV |
| 3/4H | 320–370 HV |
| FH (Full Hard) | ≥370 HV |
(as-supplied)
Note: Hardenable by quenching & tempering, achievable HRC45～55 with good wear resistance. Low hardenability and prone to distortion. Poor rust resistance; bluing, black oxide, phosphating or plating required.
Common Surface Finishes
| Surface | Description / Applications |
|---|---|
| 2B cold rolled bright finish | ideal for precision stamping |
| Blue tempered finish | widely used for springs and blades |
| Pickled finish | low cost for general parts |
Size Range & Precision Slitting (Edge trimming and deburring)
0.08–3.0 mmThickness
2 mmWidth
±0.002 mmTight tolerance available
Can be slit and precision cut per drawings. Please confirm required dimensions and achievable tolerances with your inquiry.
Material Features
- Japanese carbon tool steel, carbon level close to C67S with tight impurity control. Better wear resistance than 65Mn after quenching, but limited hardenability, best for thin gauges
- No Cr/Ni, cost-effective. Easy to rust in humid conditions, anti-corrosion treatment mandatory
- Good machinability; poor weldability. Hardness & elasticity lost after welding with high cracking risk, not for welded assemblies
- Stable spring-back, suitable for thin shrapnels and simple cutting edges; higher distortion risk for thick strips during heat treatment
Applications
Thin blades, woodworking cutters, hand saw blades, precision spring shrapnels, circlips, retaining rings, light-duty punches, shims, tape measure strips, thin mold inserts
Material Comparison
| Grade | Key Characteristics |
|---|---|
| SK7 | JIS carbon tool steel, good wear resistance, dual-purpose for blades & springs, limited hardenability |
| 65Mn | Higher manganese, better hardenability, preferred for thicker springs |
| C67S | European spring steel, balanced toughness |
| SK85 | Higher carbon, higher hardness & wear resistance but more brittle |