1.2842 | 90MnCrV8 | O2 Steel | SKS31 | 9Mn2V

1.2842 (90MnCrV8) is high‑carbon Mn‑Cr‑V oil‑hardening cold‑work tool steel. Its composition: C 0.85‑0.95 %, Mn 1.80‑2.20 %, Cr 0.20‑0.50 %, plus V. This balanced mix provides good wear resistance, high hardness and great dimensional stability in heat treatment.

1.2842 steel stands out for its superb heat‑treatment dimensional stability, with volume change of only about 1‰ (0.1 %). It also has strong crack resistance, good machinability and medium toughness. It fits precision measuring tools, machine knives, cold shear blades and thread‑cutting tools.

1.2842 material equivalent: AISI O2 (USA), JIS SKS31 (Japan), GB 9Mn2V (China), BS B02 (UK), AFNOR 90MV8 (France).

Supply Range & Tolerances

1. Round Bar

Hot Rolled / Forged: Diameter Φ16mm – Φ500mm
Forged: Diameter Φ50mm – Φ400mm (larger sizes available upon request)
Length: 2000mm – 5800mm (customizable)
Tolerances: Compliant with DIN EN ISO 4957 or ASTM A681
Surface conditions: Black skin, peeled, turned, or ground finish

1.2842 Material Flat Bar / Plate

3. Forgings / Special Shapes

1.2842 Material Equivalent

Standard System	Country/Region	Equivalent Grade	Common Search Terms
DIN / EN	Germany	1.2842, 90MnCrV8	1.2842 steel, 1.2842 material, DIN 1.2842, 90MnCrV8
AISI / ASTM	USA	O2, T31502	O2 tool steel, AISI O2
JIS	Japan	SKS31	SKS31 steel, JIS SKS31
GB	China	9Mn2V	9Mn2V steel, Chinese 1.2842 equivalent
BS	UK	B02	B02 tool steel
AFNOR	France	90MV8	90MV8 steel
UNI	Italy	90MnVCr8KU	90MnVCr8KU steel

1.2842 Composition

Standard	C	Si	Mn	P	S	Cr	V
DIN EN ISO 4957-2018	0.85‑0.95	0.10‑0.40	1.80‑2.20	≤0.030	≤0.030	0.20‑0.50	0.05‑0.20

The high manganese and carbon content in 1.2842 steel provides excellent hardenability and wear resistance. Chromium and vanadium contribute to hardness and grain refinement.

1.2842 Properties

MECHANICAL PROPERTY	METRIC VALUE	IMPERIAL VALUE
Hardness (Annealed)	≤ 229 HB	≤ 229 HB
Hardness (Quenched & Tempered)	58 – 62 HRC	58 – 62 HRC
Tensile Strength (σb)	≥ 1200 MPa	≥ 174 ksi
Yield Strength (σ0.2)	≥ 1000 MPa	≥ 145 ksi
Elongation (δ5)	≥ 12 %	≥ 12 %
Reduction of Area (ψ)	≥ 35 %	≥ 35 %

DIN 1.2842 is an oil‑hardening steel offering high wear resistance, good toughness, high dimensional stability during heat treatment, and excellent machinability. The steel is typically supplied in the annealed condition with a maximum Brinell hardness of 220–229 HB. After oil quenching at 790–820°C and tempering at 180–220°C, it achieves a working hardness of 58–62 HRC, with a maximum obtainable hardness of 63–65 HRC after quenching. Tensile and yield strength values refer to the hardened and tempered condition. Unit conversions: 1 MPa ≈ 0.145 ksi.

Delivery Condition of 1.2842

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

1.2842 Steel Application

Measuring Tools & Gauges: Precision gauges, calipers, measuring instruments, templates, jigs, and fixtures
Cutting Tools & Blades: Machine knives for wood, paper, and metal industries; cold cutting shear blades; thread cutting tools
Dies & Punches: Forming dies, blanking dies, bending dies, die plates, cutting punches, punching tools
Mold Components: Cavity plates, mold inserts exposed to abrasive stress, plastic and rubber moulds
Guide Components: Cross roller guide rails, T-slot scrapers, guiding plates, guiding rails
Industrial Components: Machine components, precision parts, slidways, scrap shear and recycling blades

Heat Treatment & Processing of 1.2842

1.2842 Steel Heat Treatment

Soft Annealing: Heat to 680-720°C, hold for 2-5 hours, then cool slowly in furnace at 10-20°C per hour to approximately 600°C, followed by air cooling. Resulting hardness ≤229 HB. Optimized for batch machining.
Stress Relieving: Heat to approximately 650°C, hold for one hour, then air cool. Recommended after rough machining to minimize distortion during hardening.
Preheating: Recommended to avoid thermal shock before austenitizing.
Austenitizing (Heating): 790-820°C. Soak time: 15-30 minutes after temperature equalization. Protect against oxidation and decarburization.
Quenching (Cooling): Oil quench (40-60°C) is the primary method. Warm bath quenching at 180-220°C is also suitable. Hardness after quenching: 63-65 HRC.
Tempering: Double tempering is recommended to increase toughness. Temper at 150-250°C for maximum hardness (58-60 HRC), or at higher temperatures for improved toughness. For optimal dimensional stability in precision tools, two tempering cycles are recommended.

Tempering Temp	As Quenched	100°C	200°C	300°C	400°C	500°C	600°C
Hardness (HRC)	63-65	63	60	56	50	42	38

For maximum wear resistance in cutting tools and dies, temper at 150-200°C (58-60 HRC). For improved toughness in forming tools, temper at higher temperatures within the range.

Processing Guide:

Forging: Hot forming temperature: 1050-850°C. Start forging at 1050°C, finish above 850°C. After forging, cool slowly and anneal.
Machining: Annealed 1.2842 steel (≤229 HB) offers very good machinability. Carbide tools recommended for batch production. Hardened parts require grinding with CBN wheels.
Polishing: Suitable for polishing applications.
EDM: Suitable for wire EDM and spark erosion.
Welding: Suitable with proper procedures.
Nitriding: Can be applied for surface hardening.
Hard Chrome Plating: Suitable.
Corrosion Resistance: Corrosion resistance is better than plain carbon steels, but 1.2842 steel will rust unless given protective treatment.

Quality Inspection & Control of DIN 1.2842

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 1.2842 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 1.2842

Q1: Why does 1.2842 have excellent dimensional stability during heat treatment?

A: DIN 1.2842 has very small deformation during heat treatment, only about 1‰. This comes from its manganese‑chromium‑vanadium alloy formula and oil‑hardening property. It is very fit for making precision gauges, templates and other workpieces with high size accuracy requirements.

Q2: What hardness range can 1.2842 reach? How does tempering affect its hardness?

A: Hardness in annealed condition ≤ 229 HB. Hardness after quenching can reach 63‑65 HRC. Tempering temperature directly changes final hardness: temper at 100°C → 63 HRC, 200°C → 60 HRC, 300°C → 56 HRC, 400°C → 50 HRC. You can adjust it according to real working conditions.

Q3: Why is 1.2842 more suitable for thin‑sheet stamping dies than other cold‑work tool steels?

A: 1.2842 steel has high compressive strength and good wear resistance. It has medium hardenability. It works well for thin‑sheet stamping and fine blanking with thickness below 6 mm. Compared with high‑alloy steel, it has better machinability and more economic cost.

Q4: Can 1.2842 be used for large‑section tools? What is the size limit?

A: Use with caution when section size is over 40 mm. 1.2842 tool steel has medium hardenability. The core of large section may not hit target hardness of 58‑62 HRC. For large‑size workpieces, choose steel with better hardenability such as 1.2379 (SKD11).

Q5: What is the comparison of wear resistance and toughness between 1.2842 and 1.2510 (O1/SKS3)?

A: 1.2842 (Mn‑Cr‑V series) has higher carbon content 0.85‑0.95 % versus 0.90‑1.05 % of 1.2510 (Mn‑Cr‑W series). Its carbides are finer and distribute more evenly, so it has slightly better wear resistance. But 1.2510 has slightly better toughness. Make choice based on impact‑resistant and wear‑resistant demands.

Q6: What cooling methods are recommended for quenching 1.2842?

A: You can use oil quenching (above 600°C/min) or salt‑bath quenching at 180‑220°C. Oil quenching is the main process. Salt‑bath quenching can further reduce deformation. Never use water quenching, or cracking will easily happen. Air cooling is optional for small sections, but hardness may be a little lower.