AISI 4140

Chromium, Molybdenum steel for applications requiring high tensile strength and toughness values, in particular in medium and large cross sections in the quenched and tempered condition. The Molybdenum additions prevent the steel from being susceptible to temper brittleness. Surface hardenable.

Product Features

Property Features

Hardenability: good
Machinability: good
Strength: good

Applications

Automotive
Gears
General Mechanical Engineering
Hydraulic Applications
Machine Parts
Mining Applications
Recycling

Technical Data

Chemical Analysis

C	Si	Mn	Ni	Cr	Mo	S	P
0.40	0.20	0.80	-	1.00	0.20	0.02	0.02

Nearest Standards

AISI	DIN	BS
4140	1.7225, 41CrMo4	EN19A

Heat Treatment

Forge	Normalize	Anneal	Stress relieve	Harden	Temper	Nitride
850-1050 °C. Cool in furnace.	840-880 °C. Air cool.	680-720 °C. Cool slowly in controlled furnace.	In the quenched and tempered condition, about 30-50 °C below the tempering temperature. Air cool. In the annealed condition, 600-650 °C. Air cool.	830-860 °C Oil quench.	540-680 °C hold for 1 hour min. at temperature, air cool. (see tempering chart)	Suitable for both liquid and gas nitriding.