4340 Round bar Annealled is a alloy structural steel . 4340 is used for engineering structural . Normally used as require good toughness , high strength , as well as the important conditioning of large size . Heavy machinery such as high load of axial , turbine shaft, larger than 250 mm in diameter of helicopter rotor shaft . Turbojet engine turbine shaft , blade , high load of transmission parts , fasteners of the crankshaft . Gear, etc.;
Can also be used for operating temperature over 400 ℃ of rotor shaft and blade, etc. . And after nitriding processing can also be used to make special performance requirements of the important parts . After low temperature tempering or can be used for ultra-high strength steel after is othermal quenching .
OTAI SPECIAL STEEL is ASTM 4340 Round bar Annealled stockholders and suppliers from china . We have more than 16 years experience in 4340 round bar Annealled , plate , steel flat bar , square supply .
4340 is a high quality Quenched and Tempered Alloy Structural steel . It belong to the high quality medium carbon . Oil Quenched & Tempered Hardenss is 28-34 HRc . 4340 Annealing delivery hardenss less than 250HB .
4340 steel properties is very similar with GB 40CrNiMo steel . JIS SNCM439 and DIN 1.6511 36CrNiMo4 Alloy structural steel . At most work environment , 4340 is equivalent with 40CrNiMo, 1.6511 36CrNiMo4, SNCM439 steel .
Last year , my customer from U.S.A. interested in ordering 3 more Forging blanks . Forging : At least 5 reductions to homogenize material forgings 4340 very big round bar Allealled . Rough-machine to dimensions and then do the heat-treating .
Heat-treat to the following properties: Yield strength = 1120 MPa (minimum) ;
Ultimate tensile strength = 1260 MPa (minimum) ;
Minimum elongation = 6% (minimum) ;
Thickness = 475 mm (thickness direction is same as blank thickness direction shown in above figure)
Length = 280 mm
Width = 280 mm
To make this very big special axis , only have three supplier in China . And in south China . Only Otai Special Steel could accept this order . The best quality , the complex processing , we could meeting your request all .
Tel: 0086-769-23190193
Fax: 0086-769-88705839
Email: jack@otaisteel.com
