Tool Steel


A-2 Tool Steel Data Sheet

AISI A-2 is an air-hardening medium alloy tool steel which is heat treatable to HRC 60-62. It has wear resistance intermediate between the oil hardening tool steels and the high carbon chromium tool steels. Because it offers a combination of good toughness along with moderate wear resistance, it has been widely used for many years in variety of cold work applications. A-2 is quite easily machined in the annealed condition and exhibits minimal distortion on hardening, making it an excellent choice for dies of complicated design.

Chemical Composition

Carbon 1.00%
Manganese 0.85%
Chromium 5.25%
Molybdenum 1.10%
Vanadium 0.25%

Typical Applications

Blanking Dies Thread Roll Dies
Forming Dies Trim Dies
Punches Shear Blades
Guages Wear Inserts
Powder Compaction Punches

Cold Work Tool Steel Comparison Chart

Thermal Treatments

Preheat : 1100/1250F (595/675C), equalize, 1350/1450F (775/790C), equalize.

Austenize : 1750/1800F (995/895C), 30/45 minutes at temperature.

Quench : Air, positive pressure vacuum to 150F (65C).

Temper : 400/1000F (205/540C), hold 2 hours at temperature, air cool. Temper twice.

Cryogenic Treating : Refrigeration treatments may improve long term dimensional stability by transforming retained austenite. Refrigeration treatments should generally be performed after the first temper, and must be followed by a temper.

Hardness and Impact Toughness Data
Air cooled from 1775F(970C)


Deg. F Deg. C
As quenched
300 150
400 205
500 260
600 315
700 379
800 425
900 480
1000 540
1100 595


Hardness Charpy C-Notch
HRC Ft. Lbs. Joules
61 31 42
60 41 56
59 37 50
58 33 45
58 31 42
58 29 39
57 41 56

Surface Treatments

A-2 can be given standard surface treatments such as nitriding, titanium nitride coating, or hard chrome plating if desired. When gas nitriding, harden from the high side of the temperature range and single temper at 1000F (540C); then use standard nitriding procedures.


A. Heat to 1600F (870C), hold 2 hours, slow cool 50F (30C)/hour maximum) to 1200F (650C), air cool.
B. Heat to 1600F (870C), hold 2 hours, cool to 1400F (760C), hold 6 hours, air cool.
Typical annealed hardness: 197/241 BHN.

Stress Relieving

Annealed Material: Heat to 1200/1250F(650/675C), hold two hours, cool in still air.
Hardened Material: Heat to 25F(15C) below original tempering temperature, hold two hours, cool in still air.


Use air hardening tool steel filler material. Annealed Material:Preheat to 400/600F(205/315C). Maintain above 400F(205C) during welding. Reanneal or temper 1400F(760C) 6 hours.
Hardened Material: Preheat to 25F(15C) below original tempering temperature (300F(150C) minimum). Maintain above 300F(150C) during welding. Cool to 150F(65C) after welding. Temper 25F(15C) below original tempering temperature.

Physical Propoerties

Modulus of Elasticity

30psix10(6) (207 GPa)
Density 0.284 lb/in3 (7861 kg/M3)
Thermal Conductivity 15 BTU/hr./ft./F 26 W/m/ °K)