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O2 1.2842 SKS93 Cold Work Tool Steel

O2 Cold Work Tool Steel offer good wear resistance, high hardness, and excellent dimensional stability during heat treatment. With moderate toughness and deep hardenability, ideal for blanking dies, punches, and gauges.

Standard: AISI O2, DIN 1.2842, JIS SKS93, GB 9Mn2V
Technique: EAF + LF + VD or ESR, forged, multi-directional forging ratio ≥4, spheroidized annealed
Shape: Round, Flat, Plates, Blocks
Heat treatment: Supplied in annealed condition, hardness ≤229 HBW; pre-hardened to 58–62 HRC (quenched and tempered) available on request
Surface Treatment: Black (hot-rolled / forged surface), turned, milled / ground, sawn ends
Tolerance: flat bars & plates thickness: +0.5/-0.0 mm (turned); forged blocks: ±0.2 mm
MOQ: 1 Ton

We supply AISI O2 in various custom sizes

Chemical Composition (%)

Grade	C	Si	Mn	Cr	W	V	P (≤)	S (≤)
1.2842 (90MnCrV8)	0.85–0.95	0.10–0.40	1.80–2.20	0.20–0.50	—	0.05–0.15	0.030	0.030
O2	0.85–0.95	≤0.50	1.40–1.80	≤0.30	—	≤0.20	0.030	0.030
SKS93	0.90–1.00	0.20–0.40	0.80–1.10	0.30–0.60	0.50–1.00	≤0.20	0.030	0.020
9Mn2V	0.85–0.95	0.20–0.40	1.70–2.00	≤0.25	—	0.10–0.25	0.030	0.020

Main characteristics of O2 tool steel

Good wear resistance – extends die and punch life
High hardness – maintains sharp edges in blanking operations
Excellent dimensional stability – minimal distortion during heat treatment
Moderate toughness – resists chipping in light-impact applications

O2 | 1.2842 | SKS93 tool steel applications

O2 steel for Precision Blanking Die

High wear resistance and good dimensional stability enable O2 to maintain sharp cutting edges and tight tolerances in fine blanking of thin-gauge sheet metal.

O2 steel for Cold Forming Die

Excellent machinability combined with reliable oil-hardening performance makes O2 a practical choice for complex-shaped cold forming dies and punches.

O2 steel for Gauge & Precision Measuring Tool

Minimal distortion in heat treatment and high attainable hardness allow O2 to produce gauges and measuring instruments with lasting dimensional accuracy.

Our Production Technology For O2 / 1.2842 (90MnCrV8 / 9Mn2V) Cold Work Tool Steel

Ultrasonic testing (UT) 100% as per SEP 1921 Class 3 D/d or E/e, ASTM A388, or EN 10228-3
Micro Cleanliness as per ASTM E45 Method A or DIN 50602
Spheroidized microstructure as per standard NADCA#207-2003
Macrostructure, microstructure, grain size, and mechanical properties shall meet the standards specified in GB/T 1299-2025 for Tool and Die Steels
Delivery condition: Annealed, hardness max. 220 – 230 HB (approx. 21 HRC)

mechanical properties & heat treatment of O2 steel

Heat temperature	Start forging temperature	Finish forging temperature	Cooling method
1000 °C	1050 – 1000 °C	≥ 850 °C	Pit, sand, or furnace cooling

Annealing

Heat slowly to 680 – 720°C (1256 – 1328°F) and soak thoroughly.
Holding time: approx. 2 – 5 hours (or 2–4 hours depending on section thickness)
Cool slowly in the furnace at a controlled rate of 10 – 20°C/h down to approximately 600°C
Then air cool to room temperature
Hardness after annealing: max. 220 HB (approx. 229 HB in some specifications)

Hardening

Preheating (recommended): Heat slowly to 600°C, then raise to austenitizing temperature.
Preheating at 300–500°C is also acceptable for smaller sections
Austenitizing temperature: 790 – 820°C (1454 – 1508°F).
Salt bath: 788°C.
Controlled atmosphere furnace: 802°C
Holding time:
For small sections: approx. 10 minutes.
For larger sections: 20 – 30 minutes after temperature equalization.
General rule: 30 minutes per 25mm of ruling section
Quenching media:
Oil (preferred) — quench immediately after holding
Warm bath at 180 – 220°C (356 – 428°F)
Martempering (salt bath) for complex shapes
Hardness after quenching: 63 – 65 HRC (surface)

Stress relieving

Perform after rough machining, heavy stock removal, or extensive machining to reduce the risk of distortion during final heat treatment
Heat carefully to approx. 650°C (1202°F)
Hold at temperature for 1 – 2 hours (or 2 minutes per mm of section thickness)
Furnace cool slowly to approximately 500°C, then air cool, or cool directly in still air

Tempering

Temper immediately after the workpiece cools to hand-warm temperature (core temperature 50 – 70°C / 122 – 158°F)
Number of tempers: Minimum 2 times — double tempering is mandatory for O2/1.2842. A third temper further increases toughness and dimensional stability
Holding time:
1 hour per 20mm of section thickness, but at least 2 hours per cycle.
Alternative: 1 hour per inch (approx. 25mm) of total thickness
Cooling method: Air cool after each tempering cycle (must cool to room temperature before next cycle)
Primary tempering range: 150 – 250°C (302 – 482°F) — highest hardness with good wear resistance
Secondary hardening: Tempering at 500 – 600°C can be used for certain applications requiring different property balances

Why Choose NSPM as Your O2 Tool Steel Supplier

Source Direct

Direct mill cooperation ensures stable supply, competitive pricing, and consistent quality. Global resource integration and strong supply chain management guarantee reliable material sourcing and long-term availability.

Stock Ready

50,000+ tons inventory across 11 warehouses enables fast delivery. Flexible cutting, short lead times, and ready stock support urgent demands and improve customers’ production efficiency.

Expert Team

600+ professionals, including R&D specialists and technical engineers, provide application-driven support. Fast response and deep tooling knowledge ensure accurate solutions for diverse industrial needs.

Fully Inspected

Strict quality control system with full traceability, UT testing, and heat treatment records. Certified standards (ISO, CE) ensure every material meets high-performance and reliability requirements.

Full-Chain Machining

From steel supply to precision machining, heat treatment, and equipment manufacturing, NSPM offers integrated solutions that enhance accuracy, efficiency, and overall tooling performance.