SKS3 | STS3 Steel | 9CrWMn Cold Work Tool Steel

SKS3 is an oil‑hardening low‑alloy cold‑work tool steel to JIS G 4404. It matches DIN 1.2510 (100MnCrW4), AISI O1 and GB 9CrWMn. Its typical chemistry: 0.90‑1.00% C, 0.90‑1.20% Mn, 0.50‑1.00% Cr, 0.50‑1.00% W. Balanced alloying brings good wear resistance, great thermal dimensional stability and uniform hardness.

SKS3 material features oil quenching with little distortion. Proper heat treatment achieves up to 60 HRC. Tungsten improves edge retention and wear performance for tight‑tolerance precision tools. It is widely used for blanking dies, forming tools, gauges and woodworking cutters.

Known aliases include K460, DF‑2, SGT and GOA. Our products comply with JIS SKS3 requirements.

Supply Range & Tolerances

1. Round Bar

2. Flat Bar / Plate

3. Forgings / Special Shapes

SKS3 Material Equivalent

Standard System	Country/Region	Equivalent Grade	Common Search Terms
JIS	Japan	SKS3	SKS3 steel, SKS3 material, material SKS3, JIS SKS3, SKS3 tool steel
DIN / EN	Germany	1.2510, 100MnCrW4	1.2510 steel, DIN 1.2510, 100MnCrW4
AISI / ASTM	USA	O1, T31501	O1 steel, O1 tool steel, O1 material, steel O1, material O1, AISI O1
GB	China	9CrWMn	9CrWMn steel, Chinese SKS3 equivalent
/	Europe	K460	K460 tool steel
/	Sweden	DF-2	DF-2 tool steel

All grades listed are equivalent designations of SKS3 steel in their respective regions. K460, DF-2 are widely recognized commercial equivalents. Keyspark Steel manufactures steel to JIS SKS3 standard and other standards.

SKS3 Composition

Standard	C	Si	Mn	P	S	Cr	W
JIS G 4404-2006	0.90-1.00	≤0.35	0.90-1.20	≤0.030	≤0.030	0.50-1.00	0.50-1.00

The manganese and chromium content in SKS3 steel provide excellent hardenability, while tungsten enhances wear resistance and edge retention. Composition can be micro-adjusted per batch order.

SKS3 Steel Properties

MECHANICAL PROPERTY	METRIC VALUE	IMPERIAL VALUE
Hardness (Annealed)	≤ 217 HB	≤ 217 HB
Hardness (Quenched & Tempered)	58 – 62 HRC	58 – 62 HRC
Tensile Strength (σb)	≥ 1630 MPa	≥ 236 ksi
Yield Strength (σ0.2)	≥ 1500 MPa	≥ 218 ksi
Elongation (δ5)	≥ 6 %	≥ 6 %

SKS3 material is a JIS standard oil‑hardening cold‑work tool steel (JIS G 4404), equivalent to AISI O1, DIN 1.2510, and GB 9CrWMn. It is typically supplied in the annealed condition with a hardness of ≤217 HB.

Delivery Condition of SKS3

Black Surface, Bright Surface, Turned Surface, Grinded Surface, Poblished surface.

SKS3 Application

Material SKS3 is a versatile cold work tool steel suitable for a wide range of applications requiring good wear resistance and dimensional stability:

Blanking & Stamping Dies: Blanking dies, punching dies, stamping dies, bending dies.
Forming Tools: Cold forming tools, drawing dies, bending tools.
Shear Blades & Cutting Tools: Shear blades, slitter knives, trimming dies, cutting edges.
Woodworking Tools: Woodworking cutters, knives, and tools requiring edge retention.
Gauges & Measuring Instruments: Precision gauges, calipers, measuring tools.
Thread Rolling Dies: Thread rolling dies, form rolls.
Mold Components: Mold bushings, ejector pins, guide pins, wear-resistant jigs.
Precision Tools: Master hobs, dowels, drill plates.
Automotive & Heavy Manufacturing: Wear components, tooling for sheet metal processing.

Heat Treatment & Processing of SKS3 Material

SKS3 Heat Treatment

Soft Annealing: Heat to 750-780°C, hold adequately, then furnace cool slowly. Resulting hardness ≤217 HB, optimized for batch machining.
Preheating: 600-650°C before austenitizing to avoid thermal shock.
Austenitizing (Heating): 790-840°C. Soak time proportional to section thickness. Protect against oxidation and decarburization.
Quenching (Cooling): Oil quench (40-60°C) is the primary method. Quench to 50-70°C, then temper immediately.
Tempering: Double tempering is recommended to eliminate retained austenite and ensure dimensional stability. Temper at 150-250°C for 58-60 HRC (maximum hardness), or at higher temperatures for improved toughness.

Tempering Temp	150-180°C	200°C	250°C	300°C	400°C
Hardness (HRC)	58-60	57-59	56-58	54-56	50-52

For maximum wear resistance in blanking and stamping tools, temper at 150-180°C (58-60 HRC). For improved toughness in forming tools, temper at higher temperatures within the range.

Processing Guide:

Forging: Heat uniformly to 1050-1100°C. Start forging at 1050°C, finish above 850°C. After forging, cool slowly in furnace or insulating media, then anneal.
Machining: Annealed SKS3 material (≤217 HB) machines well with carbide tools. Hardened parts require grinding with CBN wheels.
Polishing: This grade offers good polishability. Step polish with SiC paper #240 to #2000 followed by diamond paste.
Welding: Not recommended for highly stressed tooling components. If necessary, preheat and perform post-weld heat treatment.
Nitriding: Gas or plasma nitriding can be applied to enhance surface hardness and wear resistance for specialized applications.

Quality Inspection & Control of SKS3 Material

Full-process control:

Raw material and manufacturer control
Test : Chemical composition, mechanical properties, UT(ultrasonic testing), specification, surface condition, straightness, etc.
Packing: Wooden case or pallet or VCI plastic film

Why Purchase SKS3 from Keyspark Steel?

Fully Customizable: Dimensions, heat treatment, and hardness – all adjustable per batch order.
Certified Quality: Each batch comes with MTC certificate (EN 10204 3.1/3.2) , full chemical and mechanical test report.
ESR Option: Premium quality with Electro-Slag Remelting available for critical applications.
Stable Production: Large forging and rolling capacity ensures consistent quality across orders.
Long-Term Supply: Reserved production slots for regular customers – no interruptions.
Neutral Packaging: Oiled, wrapped, and strapped.

FAQ of SKS3:

Q1: What is SKS3?

A: SKS3 material is a high‑carbon alloy cold‑work tool steel following Japanese JIS G 4404 standard. It matches Chinese GB grade 9CrWMn. It is supplied in soft‑annealed condition with hardness around 180‑200 HB.

Q2: What is the equivalent standard of SKS3?

A: SKS3 equivalent standards: Chinese GB 9CrWMn, US ASTM O1, German DIN 1.2510 (100MnCrW4), International ISO 95MnWCr1, Swedish ASSAB DF‑3, Japanese Daido GOA, Korean KS STS3.

Q3: What is the chemical composition of SKS3?

A: Typical composition (wt %): C 0.90‑1.05, Si ≤0.35, Mn 0.90‑1.20, P ≤0.030, S ≤0.030, Cr 0.50‑1.00, W 0.50‑0.90.

Q4: What is the hardness of SKS3 after heat treatment?

A: After oil quenching at 800‑850 °C and tempering at 150‑200 °C, SKS3 reaches over 60 HRC, and can hit 60‑62 HRC according to some references. Annealed (delivery‑state) hardness is around 180‑200 HB.

Q5: What are the key properties of SKS3?

A: Material SKS3 is known as “non‑deforming steel”. It combines high toughness, good wear resistance, fair hardenability and stable dimensional performance after heat treatment. It has clean steel structure and good machinability after spheroidize annealing. Quenching distortion is very small, so it fits complex precision tools.

Q6: What is SKS3 mainly used for?

A: SKS3 material applies to thin‑sheet dies such as blanking dies, stamping dies, bending dies and sizing dies for thickness up to 8 mm. It also makes gauges, measuring tools, woodworking cutters, lathe centers, guide bushes, threading dies and thread pins and other precision tools.