The high-carbon workhorse for parts that must take a load — springs, saw blades, clutch plates — supplied either spheroidized for fine blanking or hardened-and-tempered for finished properties.
SAE1078 sits above SAE1065 for load capacity, below tool steels like SK5 for edge retention — and it is significantly easier to work in the annealed condition than either. That middle ground is exactly where a lot of production parts live.
More carbon means higher achievable hardness and better load capacity — the right call when your spring or plate sees real stress, not just form.
Choose 1078 when the part carries load after hardening.SK5 gives harder edges for cutting tools but is less forgiving to blank and heat treat. 1078 delivers most of the performance with better formability and lower cost.
Choose 1078 when edge retention is secondary to toughness and cost.65Mn adds manganese for hardenability in heavier sections; 1078 is the leaner, more consistent choice for thin strip where alloy additions are unnecessary.
Choose 1078 for thin-gauge strip; 65Mn for thicker sections.Values per AISI 1078 specification; actual heats confirmed on the Mill Test Certificate.
| Element | Typical range (%) |
|---|---|
| Carbon (C) | 0.72 – 0.85 |
| Manganese (Mn) | 0.30 – 0.60 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.050 |
Reference: AISI 1078. Confirm final chemistry with the MTC of the delivered heat.
Indicative ranges for strip; final values depend on gauge, process and inspection plan agreed at order.
| Condition | Tensile (typ.) | Hardness (typ.) | Typical use |
|---|---|---|---|
| Spheroidized (soft annealed) | 540 – 620 MPa | 160 – 200 HB | Fine blanking, cold forming, blanked-then-hardened parts |
| Hardened & tempered | 1,150 – 1,450 MPa | 38 – 48 HRC | Springs, blades, clutch plates in finished condition |
Indicative only. Hardenability is confirmed by trial or inspection report for your section size and heat treat cycle.
Substitution must be confirmed against your governing standard — chemistry and hardenability can differ by source.
| Standard | Grade | Notes |
|---|---|---|
| ASTM / AISI | SAE1078 / AISI 1078 | Base reference |
| GB (China) | 75# (approx.) | Confirm against GB/T 699 |
| DIN (Germany) | Ck75 (approx.) | Confirm against EN 10083 |
| JIS (Japan) | S75C (approx.) | Confirm against JIS G4051 |
Blanked from spheroidized strip, then hardened and tempered to a stable spring rate. Consistent chemistry across the coil keeps the heat treat result repeatable.
Annealed strip blanks cleanly, then hardens to a tough, crack-resistant blade body that stays flat through the furnace.
Thin-gauge 1078 takes a sharp, durable edge without the cost or brittleness of higher-alloy tool steel.
High carbon gives the set resistance you need from a stamped clip — supplied slit to progressive-die coil widths.
Full cycle conditioning the carbide structure for clean fine blanking and cold forming — the difference between a clean shear face and a torn one.
Multi-pass rolling to your gauge tolerance, with controlled surface finish for blanking and forming.
Width tolerance and burr managed on our line — coils for progressive dies, sheets for laser and blanking feeders.
We quote spheroidized or H&T per your route, and our engineers advise on the cycle that suits your section.
For SAE1078 and similar high-carbon grades: chemistry ranges, hardness bands after spheroidizing annealing, thickness and width tolerances, surface finish and edge condition — the specification framework to get consistent shear quality and die life.
These grade families share material, processing or application territory with the topic on this page.
SAE1078 / 65Mn / SK5 grades for hardened parts, springs and cutting edges.
65Mn / 50CrV4 / 60Si2Mn grades with high elastic limit and fatigue resistance.
SK5 / SK7 / T8A / T10A grades with wear resistance and edge hardness for cutting tools.
Include thickness × width, quantity, condition (spheroidized or H&T) and destination port. Our engineers reply within one working day.