Steel SKS3
JIS SKS3
SKS3 is a low-alloy oil-hardening cold-work tool steel to JIS G 4404, with about 0.95% C strengthened by Mn, Cr and W, and is equivalent to AISI O1, DIN 1.2510 (100MnCrW4) and GB 9CrWMn.
Values for the Annealed condition
SKS3 tempers and conditions
SKS3 is supplied in 3 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize annealed, soft supply condition | Standard stock condition for bar, flat and ground stock — machine to shape here, then harden. | 450 | 750 | 18 | 200 HB | — |
oil quench + 150–200 °C temper, 60–62 HRC | Choose for gauges, blanking dies and cutting edges where maximum wear resistance and dimensional stability matter. | 1,950 | 2,200 | 1 | 61 HRC | — |
800–830 °C oil quench, untempered | Intermediate condition only — maximum hardness but highly stressed; must be tempered promptly. | 2,000 | 2,350 | 0 | 64 HRC | 5.5 % IACS |
What is SKS3?
SKS3 is a low-alloy oil-hardening cold-work tool steel to JIS G 4404, with about 0.95% C strengthened by Mn, Cr and W, and is equivalent to AISI O1, DIN 1.2510 (100MnCrW4) and GB 9CrWMn. Oil quenching with low-temperature tempering produces small dimensional change and a stable hardness above 60 HRC, which is why it is used for gauges, blanking dies, paper knives and thread-cutting tools. Annealed stock is about 450 MPa yield, 750 MPa tensile, 18% elongation and 200 HB (94 HRB, machinability 50). Hardenability suits small to medium sections only, hardness falls rapidly above about 200 °C, corrosion resistance is poor and weldability is very poor. SKS3 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). SKS3 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 52% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is SKS3 used for?
- Gauges and measuring tools
- Blanking and piercing dies
- Paper and guillotine knives
- Taps and threading dies
- Punches
- Shear blades
- Reamers and broaches
- Woodworking cutters
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
Limitations
- Difficult to weld — 12/100, worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades
SKS3 properties
Typical room-temperature values for SKS3-Annealed; bars are the position among steel grades.
Physical3
SKS3 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
SKS3 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 52% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
SKS3 is rated for continuous service to 200°C (392 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
SKS3 conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of SKS3 takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
SKS3's machinability is fair (50/100, worse than 53% of steel grades); weldability not recommended (12/100); formability poor (25/100).
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. SKS3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SKS3
Is SKS3 easy to machine?
Machine fully in the annealed condition with sharp carbide or HSS tooling; after hardening only grinding, EDM or hard turning at ≤61 HRC is practical.
Can SKS3 be welded?
Poor weldability — high carbon promotes cracking; repair only with matched tool-steel filler, 300–400 °C preheat and immediate re-temper.
Can SKS3 be formed, bent or molded?
Cold forming limited to gentle bending of thin annealed stock; hot work 850–1050 °C followed by slow cooling and spheroidize anneal at 760–790 °C.
Manufacturability
The process limits FabDigit applies to SKS3. Every SKS3 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better50 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
SKS3 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 |
|---|---|---|
| C | 0.9 – 1 | 0.95 |
| Simax per JIS G 4404 | ≤ 0.35 | 0.25 |
| Mn | 0.9 – 1.2 | 1.05 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 0.5 – 1 | 0.65 |
| W | 0.5 – 1 | 0.65 |
| Niresidual, max | ≤ 0.25 | |
| Curesidual, max | ≤ 0.25 | |
| Fe | balance |
What surface finishes work on SKS3?
Takes a fine ground and lapped or mirror-polished finish; protect with oil, black oxide, phosphate, hard chrome or nitriding since bare surfaces rust quickly.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel SKS3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- JIS
- G 4404 SKS3
- Other
- O1
How much does SKS3 cost?
SKS3 is a premium-cost steel ($$$), pricier than about 57% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
SKS3 — frequently asked
What is SKS3 used for?
SKS3 is typically used for gauges and measuring tools, blanking and piercing dies, paper and guillotine knives, taps and threading dies, punches and shear blades. In short: oil-hardening tool steel.
What is the yield strength of SKS3?
SKS3 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is SKS3 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine fully in the annealed condition with sharp carbide or HSS tooling; after hardening only grinding, EDM or hard turning at ≤61 HRC is practical.
Can SKS3 be welded?
Not readily — weldability is rated not recommended (12/100). Poor weldability — high carbon promotes cracking; repair only with matched tool-steel filler, 300–400 °C preheat and immediate re-temper.
What surface finishes work on SKS3?
Takes a fine ground and lapped or mirror-polished finish; protect with oil, black oxide, phosphate, hard chrome or nitriding since bare surfaces rust quickly.
Can SKS3 be formed, bent or molded?
Cold forming limited to gentle bending of thin annealed stock; hot work 850–1050 °C followed by slow cooling and spheroidize anneal at 760–790 °C.
What is the maximum service temperature of SKS3?
SKS3 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does SKS3 cost?
SKS3 is a premium-cost steel ($$$), pricier than about 57% 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.
Can FabDigit make parts in SKS3?
Yes — SKS3 is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 4404 Alloy tool steels — JSA (2015)
- GB/T 1299 Tool and die steels (9CrWMn) — SAC (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (Oil-hardening cold-work tool steels) — ASM International (1991)
- 1.2510 / 100MnCrW4 cold work tool steel datasheet — Böhler / Buderus Edelstahl (2021)
- (SKS3 / 9CrWMn) — Mysteel / 1688 (2025)
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.