4130 Alloy steel

OTAI SPECIAL STEEL is 4130?Alloy steel stockholders and suppliers from china. more 16 years experience in 4130 steel supply.

AISI 4130 alloy?Steel is a?high?quality Quenched and Tempered Alloy Structural steel, It?belong to the high quality low carbon, Oil Quenched & Tempered Hardenss is 28-34 HRc. AISI 4130 steel Annealing delivery hardenss less than 250HB.

AISI 4130 Alloy structural steel?properties is a chromium molybdenum alloy steel specification. 4130 With a lower carbon content range, So the 4130 alloy steel have better weldability than AISI 4140 Alloy steel.

Related Specifications?ASTM A29/A29M DIN EN 10083/3 JIS G4053 GB GB/T 3077

4130 steel data files Down

Form of Supply

AISI 4130 Alloy steel, we can supply the round bar, steel flat bar, plate, hexagonal steel bar and steel square block. AISI 4130?steel Round bar?can be sawn to your required lengths as one offs or multiple cut pieces. 4130 alloy steel Rectangular pieces can be sawn from flat bar or plate to your specific sizes. Ground tool steel bar can be supplied, providing a quality precision finished bar to tight tolerances.

Chemical composition

C(%) 0.28~0.33 Si(%) 0.15~0.35 Mn(%) 0.40~0.60 P(%) ≤0.035
S(%) ≤0.040 ?Cr(%) 0.80~1.10 ?Mo(%) 0.15~0.25

Heat treatment Related

  • Annealing of 4130 Alloy structural steel

Slowly heated to 850 ℃ and allow enough times, let the steel to be thoroughly heated, Then cool slowly in the furnace to 480 ℃ follow by air cool. The 4130 alloy steel will get MAX 250 HB (Brinell hardness).

  • Normalizing of 4130 Alloy structural steel

Heated slowly to 850-880°C,Keep about 2 hours.Then cool in air.

  • Hardening of 4130 Alloy structural steel

Heated slowly to 870-890°C, Then after adequate soaking at this temperature quench in oil. Temper as soon as tools reach room temperature.

  • Tempering of 4130 Alloy structural steel

Heated to 400-565°C, Keep at the temperature for 2 hours per 25mm of section, then allow to cool in air.

Mechanical Properties in Tempering Condition(18-22 HRC)

Tensile 0.2%?Proof Stress Elongation Reduction Hardness Hardness
KSI KSI % of Area % HRc Brinell
Min 95 75 20 40 18 217
Max 130 110 22 235



AISI 4130 steel is widely used for a variety of applications in the oil and gas sector. Typical applications such as valve bodies, pumps and fittings, Shaft, spindle, and the high load of wheel, bolts, double-headed bolts, gears, etc

Regular size and Tolerance

1) Hot Rolled round bar
Diameter Tolerance
Diameter Tolerance
≤12.70 -0.13 ~0.30 >50.80~63.5 -0.25~0.76
12.7~25.40 -0.13~0.41 >63.50~76.20 -0.25~1.02
>25.4~38.10 -0.15~0.51 >76.20~101.60 -0.30~+1.27
>38.1~50.80 -0.20~0.64 >101.60~203.20 -0.38~3.81
2) Hot Rolled steel plate
Thickness Tolerance
Thickness Tolerance
≤25.4 -0.41~0.79 >127~152 -1.60~2.39
>25.4~76 -0.79~1.19 >178~254 -1.98~3.18
>76~127 -1.19~1.60 >254~305 -2.39~3.96

Others 4130 have not specified size, pls contact our?experienced sales team.


AISI 4130 alloy steel round bar and flat sections can be cut to your required sizes. 4130 alloy steel ground bar can also be supplied, providing a high quality tool steel precision ground tool steel bar to your required tolerances. AISI 4130 steel is also available as Ground Flat Stock / Gauge Plate, in standard and nonstandard sizes.

Contact our experienced sales team to help you with your 4130 alloy steel questionsadn enquiry?by?Email or Telphone.?The questions will be reply in 24 hours.

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