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90MnCrV8 (O1)

Oil-hardening cold work tool steel O1 / 90MnCrV8. Low distortion on hardening. For punches, dies, gauges and precision tools.

Tool Steels Cold Work Tool Steel EN / ISO90MnCrV8 DIN1.2510 AISI/SAEO1 ASTMA681 Grade O1 +14
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Description

90MnCrV8 (EN 1.2510 / AISI O1) per EN ISO 4957. Oil-hardening cold work tool steel with excellent dimensional stability during hardening (low distortion). Mn addition improves hardenability; V adds wear resistance. HRC 60-64. Standard for precision gauges, punches, form tools and dies where dimensional accuracy is critical.

Key Properties β€” Annealed
Hardness
β€” – 229
HB
E (Young's Modulus)
210
GPa
Density
7.85
g/cmΒ³
Main Designations (18)
Standard BodyDesignationCountry / RegionNote
EN / ISO 90MnCrV8 EU / International
DIN 1.2510 Germany
AISI/SAE O1 USA
ASTM A681 Grade O1 USA
BS BO1 UK
JIS SKS3 Japan
GOST 9HVG (9KhVG) Russia / CIS
UNI 90MnCrV8 Italy
NF 90MnCrV8 France
SS 2140 Sweden
PN NNV Poland
CSN 19313 Czech Republic
BOHLER K460 Austria (trade name)
JUS C.7620 Yugoslavia / Serbia Oil-hardening cold work tool steel; JUS C.B5.040
UNS T31501 USA (UNS)
EN / ISO 90MnCrV8 / 1.2510 EU
AISI/SAE O1 (oil-hardening) USA
JUS C.7630 Yugoslavia Alatni čelik za hladno oblikovanje O1; JUS C.B5.040
Standards (18)
#Standard BodyDesignationCountry / RegionNote
1 EN / ISO 90MnCrV8 EU / International β€”
2 DIN 1.2510 Germany β€”
3 AISI/SAE O1 USA β€”
4 ASTM A681 Grade O1 USA β€”
5 BS BO1 UK β€”
6 JIS SKS3 Japan β€”
7 GOST 9HVG (9KhVG) Russia / CIS β€”
8 UNI 90MnCrV8 Italy β€”
9 NF 90MnCrV8 France β€”
10 SS 2140 Sweden β€”
11 PN NNV Poland β€”
12 CSN 19313 Czech Republic β€”
13 BOHLER K460 Austria (trade name) β€”
14 JUS C.7620 Yugoslavia / Serbia Oil-hardening cold work tool steel; JUS C.B5.040
15 UNS T31501 USA (UNS) β€”
16 EN / ISO 90MnCrV8 / 1.2510 EU β€”
17 AISI/SAE O1 (oil-hardening) USA β€”
18 JUS C.7630 Yugoslavia Alatni čelik za hladno oblikovanje O1; JUS C.B5.040
All values in wt.%
C
Carbon
0.8500 – 0.9500
Si
Silicon
0.1000 – 0.4000
Mn
Manganese
1.0000 – 1.2000
Cr
Chromium
0.3000 – 0.6000
V
Vanadium
0.0500 – 0.1500
W
Tungsten
0.4000 – 0.7000
ElementSymbolMin %Max %Typical %
Carbon C 0.8500 0.9500 0.9000
Silicon Si 0.1000 0.4000 0.2500
Manganese Mn 1.0000 1.2000 1.1000
Chromium Cr 0.3000 0.6000 0.4500
Vanadium V 0.0500 0.1500 0.1000
Tungsten W 0.4000 0.7000 0.5500
Mechanical Properties
ConditionCode Rm min
MPa		Rm max
MPa		 Re min
MPa		Re max
MPa		 Aβ‚… min
%		 Z
%		 KV
J		 HB minHB max HRC minHRC max E
GPa
Annealed +A β€” β€” β€” β€” β€” β€” β€” β€” 229 β€” β€” 210.0
H+T 150 C (gauge) H+T150 β€” β€” β€” β€” β€” β€” β€” β€” β€” 61.0 64.0 210.0
H+T 200 C (punch) H+T200 β€” β€” β€” β€” β€” β€” β€” β€” β€” 60.0 62.0 210.0
Physical Properties
Density
7.850
g/cmΒ³
Melting Point
1280–1380
Β°C
Young's Modulus
210.0
GPa
Poisson's Ratio
0.280
β€”
Thermal Conductivity
35.0
W/mΒ·K
Thermal Expansion
11.50
Γ—10⁻⁢ /K
Specific Heat
460
J/kgΒ·K
Electrical Resistivity
0.5800
¡Ω·m
Magnetic
Yes
 
Heat Treatment
Soft Annealing
Temperature:740Β°C – 800Β°C
Medium:Furnace
Duration:4-8 h
Cooling:<=15 C/h
Hardness After:<=HB 220
Spheroidise β€” mandatory before machining.
Austenitizing
Temperature:790Β°C – 820Β°C
Medium:Oil ONLY
Duration:15-25 min
Cooling:Oil quench β€” never water
Hardness After:HRC 63-66 (before temper)
Low temp β€” excellent dimensional control.
Tempering (double)
Temperature:150Β°C – 200Β°C
Medium:Air oven
Duration:2x2h
Cooling:Air cool between tempers
Hardness After:HRC 60-64
Double temper mandatory.
Machinability
Machinability Rating
relative to AISI B1112 = 100%
25.0%
Very Difficult
Turning Speed (HSS)
12
m/min
Turning Speed (Carbide)
65
m/min
Feed Rate (Turning)
0.090
mm/rev
Drilling Speed (HSS)
7
m/min
Milling Speed (Carbide)
70
m/min
CoolantSoluble oil 8-12%
Chip FormationShort brittle chips
Tool MaterialCarbide P30/K20; CBN (hardened); grinding (hardened)
Surface FinishRa 0.4-0.8 um (annealed)
Moderate machinability. Standard workshop tool steel. Low austenitising temperature means easy workshop hardening.
Applications
Gauges
Precision gauges, thread gauges, block gauges and GO/NO-GO gauges.
Punches & Dies
Punches, piercing tools, forming dies and blanking dies for light production runs.
Pattern Making
Pattern tools, die inserts and low-volume stamping tools.
Toolmaking
Punches, dies, blanking tools, piercing tools for prototype and short-run production.
Gauges
Precision gauges, gauge blocks, plug gauges and ring gauges.
Cutters
Lathe centres, boring bars, form cutters and engraving tools.
Technical Notes
βœ…
vs D2
O1 is cheaper, easier to machine and heat treat with lower distortion. D2 gives 5-10x better wear resistance for long production runs. Use O1 for prototypes and short runs; D2 for production tooling.
βœ…
Dimensional Stability
O1 (oil-hardening) has significantly less distortion than W-series (water-hardening) steels. It is THE standard low-distortion, low-cost cold work tool steel.
βœ…
O1 vs D2
O1: oil quench (more distortion than air-hardening D2, but simpler), lower wear resistance, lower cost, suitable for runs <50,000 shots. D2: air hardening (minimal distortion), 5x better wear resistance, for runs >500,000 shots. Use O1 for prototyping, gauges and short-run tooling.
βœ…
Forgiving HT
O1 is one of the most forgiving tool steels to heat treat β€” wide austenitising temperature window, clear colour change at austenitising temp, no complex preheating. Ideal for small workshops.