4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel


4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel according to AMS 6411, AMS 6427, MIL-S-8699, Airesearch EMS-96242, CE-0906, BMS 7-122, BMS 7-27, FMS-1012, GM-1010, AMS STD 2154, GE S-400 S-1000

4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel - Introduction and Application

4330M, 4330 MOD, 4330V is a low alloy high strength steel melted as AOD + VAR or EAF+LF+VD+VAR.  It has added vanadium which improves impact strength as well as hardenability.  It's high strength and excellent fatigue strength lends itself to demanding aerospace applications similar to 4340 and 300M. has alloy steel are used in aircraft landing gears, shafts or axels for power transmission and gears.


Melted process

AOD + VAR

EAF+LF+VD+VAR


4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel - Chemical composition WT %

GradeChemical composition WT %
CSiMnPSCrMoAlNiVCuTiO2N2
4330V, UNS K230800.31 - 0.330.15 - 0.350.80 - 0.95Max 0.015Max 0.0050.8 - 1.00.45 - 0.500.015 - 0.035-0.06 - 0.10



4330M0.48 - 0.530.15 - 0.350.75 - 1.00Max 0.035Max 0.040.8-1.10.15 - 0.25






4330 MOD, UNS K230800.28 - 0.330.15 - 0.350.40 - 0.60Max  0.010Max  0.0020.80 - 1.100.15 - 0.25-Max 0.250.05 - 0.10Max 0.07Max 0.005Max 0.002Max 0.005

Mechanical Property of 4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel

PropertiesMetricImperial
Tensile strength≥ 860 MPa≥ 125000 psi
Yield strength≥ 690 MPa≥ 100000 psi
Elongation at break (In 50 mm)≥ 15.0 %≥ 15.0 %
Hardness, Brinell285285



Physical Property of 4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel

PropertiesMetricImperial
Melting point1427°C2600°F

Heat Treatment of 4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel

4330 alloy steel is heated to 829°C (1525°F) and then quenched in oil. 4330 alloy steel can also be heat treated to strength levels of 200 ksi or greater than 200 ksi, by first being normalized at 899°C (1650°F) before the heat treatment and then quenched to gain strength.

Forging: 1230-1070 °C 

Rolling: 1230-1070 °C 

Annealing: 820-860 °C



Welding of 4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel

Conventional methods are used for welding 4330 alloy steel. 4330 alloy steel is preheated and post heated based on the welding procedure used for this alloy steel type, and the alloy can be joined by a brazing process.


Machining of 4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel

4330 alloy steel has good machinability features in the annealed, tempered and normalized conditions. This alloy steel is difficult to be machined in the hardened condition.


Equivalent grades of 4330M, 4330 MOD, 4330V, UNS K23080 low alloy high-strength steel

4150, 4330V, 4330MOD, 4330+V, 4335+V LATROBE, 5029B, AMS6411, AMS6411D, AMS6427, AMS6427H, AMS6429, AMS6429D, AMS6430, AMS6430E, AMS6433, AMS6433D, AMS6434, AMS6434D, AMS6435, AMS6435C, ASTMA646, UNSK23080, UNSK33517, LESCALLOY 4330+V, K33517, MIL S-8699, MIL S-46128