Steel SK95
JIS SK95 · GB T9A
SK95 is a JIS G4401 carbon tool steel containing about 0.95 %C, essentially equivalent to T9A, supplied annealed, hot rolled, normalized, cold rolled (annealed or hard) and in quenched-and-tempered conditions.
Reference datasheet — SK95 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the A condition
SK95 tempers and conditions
SK95 is supplied in 10 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cold Rolled, annealed strip | Choose bright cold-rolled strip in the soft annealed state (185 HB, 20% elongation) for blanking and forming blades, shims and spring leaves that are hardened after forming. | 390 | 650 | 20 | 185 HB | 9.5 % IACS |
ADefault Solution annealed | Order this spheroidize-annealed state as the standard supply condition for machining and press blanking at minimum hardness (192 HB), then quench and temper in-house to working hardness. | 400 | 670 | 22 | 192 HB | — |
Hot rolled | Pick the unannealed as-rolled bar for lowest stock cost, and budget a spheroidizing anneal before machining because 240 HB and 12% elongation cut and form poorly. | 460 | 800 | 12 | 22 HRC | 9.5 % IACS |
Normalized | Use after forging or rough machining to refine grain and break up carbide networks at 270 HB; it is a preparation step for spheroidize annealing or hardening, not a service condition. | 520 | 900 | 10 | 27 HRC | 9.4 % IACS |
Cold Rolled hard strip | Pick work-hardened cold-rolled strip when thin parts need spring action and flatness straight from coil at 32 HRC; elongation of 3% limits any further forming or machining. | 900 | 1,050 | 3 | 32 HRC | 9 % IACS |
Quenched + tempered 500 °C | Use the 500 °C temper (38–43 HRC) for structural tool parts that must absorb impact rather than resist wear; toughness peaks at 9% elongation with 1280 MPa tensile strength. | 1,100 | 1,280 | 9 | 41 HRC | 9 % IACS |
Quenched + tempered 400 °C | Pick the 400 °C temper at 45–49 HRC for spring leaves, retaining clips and thin parts that must flex elastically, accepting lower hardness in exchange for 6% elongation. | 1,300 | 1,500 | 6 | 47 HRC | 8.8 % IACS |
Quenched + tempered 300 °C | Choose the 300 °C temper (52–56 HRC) when chisels, punches and shear blades carry heavy impact loads, giving up wear resistance for 3% elongation and 250 °C service. | 1,550 | 1,800 | 3 | 54 HRC | 8.5 % IACS |
Quenched + tempered 200 °C | Use quenching with a 200 °C temper at 58–61 HRC as the normal working hardness for cutting edges and punches, trading a little hardness for usable toughness. | 1,750 | 2,050 | 1 | 60 HRC | — |
Quenched (water) + tempered 150–180 °C | Specify water quenching plus a 150–180 °C temper to 62–64 HRC for razors, carving tools and wood chisels needing maximum edge retention; 0.5% elongation tolerates no impact. | 1,900 | 2,250 | 0.5 | 63 HRC | — |
What is SK95?
SK95 is a JIS G4401 carbon tool steel containing about 0.95 %C, essentially equivalent to T9A, supplied annealed, hot rolled, normalized, cold rolled (annealed or hard) and in quenched-and-tempered conditions. It is chosen for hand tools, blades and small dies that need a hard, easily resharpened edge at low material cost, mainly as strip, sheet and bar. Hardening is by water or brine quench from 760–800 °C, so hardenability is shallow and distortion risk is high; there is no corrosion resistance and the listed service limit is 400 °C. SK85 shifts the balance toward toughness, SK105 toward wear resistance. SK95 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). SK95 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 670 MPa (97.2 ksi) — weaker than 60% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
What is SK95 used for?
- hand tools
- blades
- small dies
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High electrical conductivity — 9.5 % IACS, better than 75% of steel grades
Limitations
- Difficult to weld — 15/100, worse than 91% of steel grades
SK95 properties
Typical room-temperature values for SK95-A; bars are the position among steel grades.
Physical3
SK95 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
SK95 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 670 MPa (97.2 ksi) — weaker than 60% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SK95 is rated for continuous service to 400°C (752 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
SK95 conducts electricity at 9.5 % IACS, better than 75% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of SK95 takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability8
SK95's machinability is good (55/100, better than 62% of steel grades); weldability poor (15/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. SK95 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SK95
Is SK95 easy to machine?
In the spheroidize-annealed condition (≤207 HB) it turns, mills and drills normally with HSS or carbide. After hardening, only grinding or EDM is practical.
Can SK95 be welded?
At about 0.95 %C welding readily produces cracks and a hard, brittle heat-affected zone. If welding is required, preheat 250–350 °C, use low-hydrogen filler and temper immediately.
Can SK95 be formed, bent or molded?
Annealed sheet and strip can be blanked, bent and coiled. Quench from 760–800 °C in water or brine — hardenability is shallow and distortion and cracking risk is high — then temper immediately.
SK95 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CJIS G4401 SK95 (formerly SK4) | 0.9 – 1 | 0.95 |
| Si | 0.1 – 0.35 | 0.25 |
| Mn | 0.1 – 0.5 | 0.3 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Curesidual element | ≤ 0.25 | |
| Niresidual element | ≤ 0.25 | |
| Crresidual element | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on SK95?
After hardening it can be finish ground and polished to a mirror surface. It has no corrosion resistance, so bluing, phosphating, oiling or nickel/chrome plating is required.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel SK95 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GB (China)
- T9A
How much does SK95 cost?
SK95 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
SK95 — frequently asked
What is SK95 used for?
SK95 is typically used for hand tools, blades and small dies. In short: JIS equivalent of T9A; low-cost blade steel; water-hardening, shallow depth.
What is the yield strength of SK95?
SK95 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 670 MPa (97.2 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is SK95 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). In the spheroidize-annealed condition (≤207 HB) it turns, mills and drills normally with HSS or carbide. After hardening, only grinding or EDM is practical.
Can SK95 be welded?
Not readily — weldability is rated poor (15/100). At about 0.95 %C welding readily produces cracks and a hard, brittle heat-affected zone. If welding is required, preheat 250–350 °C, use low-hydrogen filler and temper immediately.
What surface finishes work on SK95?
After hardening it can be finish ground and polished to a mirror surface. It has no corrosion resistance, so bluing, phosphating, oiling or nickel/chrome plating is required.
Can SK95 be formed, bent or molded?
Annealed sheet and strip can be blanked, bent and coiled. Quench from 760–800 °C in water or brine — hardenability is shallow and distortion and cracking risk is high — then temper immediately.
What is the maximum service temperature of SK95?
SK95 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SK95-A and SK95-QT160?
A is the default condition — order this spheroidize-annealed state as the standard supply condition for machining and press blanking at minimum hardness (192 HB), then quench and temper in-house to working hardness. QT160: specify water quenching plus a 150–180 °C temper to 62–64 HRC for razors, carving tools and wood chisels needing maximum edge retention; 0.5% elongation tolerates no impact. Yield strength is 400 MPa in A versus 1,900 MPa in QT160.
How much does SK95 cost?
SK95 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- JIS G4401 Carbon tool steels — JISC (2009)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.