Chemical Composition
Element	Content (%)
Iron, Fe	97.03 – 98.22
Chromium, Cr	0.80 – 1.10
Manganese, Mn	0.40 – 0.60
Carbon, C	0.280 – 0.330
Silicon, Si	0.15 – 0.30
Molybdenum, Mo	0.15 – 0.25
Sulfur, S	0.040
Phosphorous, P	0.035

 

Mechanical Properties
Properties	Metric	Imperial
Tensile strength, ultimate	560 MPa	81200 psi
Tensile strength, yield	460 MPa	66700 psi
Modulus of elasticity	190-210 GPa	27557-30458 ksi
Bulk modulus (Typical for steel)	140 GPa	20300 ksi
Shear modulus (Typical for steel)	80 GPa	11600 ksi
Poissons ratio	0.27-0.30	0.27-0.30
Elongation at break (in 50 mm)	21.50%	21.50%
Reduction of area	59.6	59.60%
Hardness, Brinell	217	217
Hardness, Knoop (Converted from Brinell hardness)	240	240
Hardness, Rockwell B (Converted from Brinell hardness)	95	95
Hardness, Rockwell C (Converted from Brinell hardness, value below normal HRC range, for comparison purposes only.)	17	17
Hardness, Vickers (Converted from Brinell hardness)	228	228
Machinability (Annealed and cold drawn. Based on 100% machinability for AISI 1212 steel.)	70	70

 

Physical Properties
Properties	Metric	Imperial
Density	7.85 g/cm³	0.284 lb/in³
Melting point	1432°C	2610°F

 

Thermal Properties
Properties	Metric	Imperial
Thermal conductivity (100°C)	42.7 W/mK	296 BTU in/hr.ft2. °F

 

Other Designations

Other designations that are equivalent to AISI 4130 alloy steel include the following.

AMS 6348	AMS 6371	ASTM A331	ASTM A829	DIN 1.7218
AMS 6350	AMS 6373	ASTM A506	MIL S-18729	UNI 25 CrMo 4
AMS 6351	AMS 6374	ASTM A507	MIL S-6758	JIS SCCrM 1
AMS 6360	AMS 6528	ASTM A513	SAE J1397	JIS SCM 2
AMS 6361	AMS 7496	ASTM A519	SAE J404	SS 2225
AMS 6362	ASTM A29	ASTM A646	SAE J412	B.S. CDS 110
AMS 6370	ASTM A322	ASTM A752	AFNOR 25 CD 4 (S)	SAE J770

 

Fabrication and Heat Treatmen

Machinability

AISI 4130 steel can be easily machined using conventional methods. However, machining becomes difficult when the hardness of the steel is increased.

Forming

Forming of AISI 4130 steel can be performed in the annealed condition.

Welding

Welding of AISI 4130 steel can be performed by all commercial methods.

Heat Treatment

AISI 4130 steel is heated at 871°C (1600°F) and then quenched in oil. This steel is usually heat-treated at temperatures ranging from 899 to 927°C (1650 to 1700°F).

Forging

Forging of AISI 4130 steel can be performed can be performed at 954 to 1204°C (1750 to 2200°F).

Hot Working

Hot working of AISI 4130 steel can be done at 816 to 1093°C (1500 to 2000°F).

Cold Working

AISI 4130 steel can be cold worked using conventional methods.

Annealing

AISI 4130 steel can be annealed at 843°C (1550°F) followed by air cooling at 482°C (900°F).

Tempering

Tempering of AISI 4130 steel can be performed at 399 to 566°C (750 to 1050°F), depending on the desired strength level.

Hardening

Hardening of AISI 4130 steel can be done with cold working or heat treatment.

Applications

The following are some of the major applications of AISI 4130 alloy steel:

• Aircraft engine mounts
• Welded tubing