4340 steel vs 8620 steel: For the different material comparisons, which one we should choose to use?

4340 steel China suppliers, wholesale, distributors, and stockholder–Dongguan Otai Special Steel Co Ltd. We Otai is a manufacturer and has a large quantity of stock in our warehouse. We supply in Round bar, gauge plate steel, pipe, tube, rod, square, hexagonal, blanks, plate, sheet, precision ground flat bar. Including precision ground bar stock, hollow bar, we provide black surface and black surface alloy steel material.

4340 alloy structural steel belongs to gear steel.

It is used for important tempering parts that require good toughness, high strength, and large size. Such as heavy machinery high-load shaft, turbine shaft with a diameter greater than 250mm. Also, it can be used for helicopter rotor shaft, turbojet engine turboshaft, blade, high-load transmission parts, crankshaft fasteners and etc. Besides, it can also be used for rotor shaft and blade with an operating temperature of over 400℃. It can also be used to make important parts with special performance requirements after nitriding treatment, which can be used for ultra-high-strength steel after low-temperature tempering or isothermal quenching.

8620 is the structural steel with the hardenability guaranteed by American standard, and the standard is as follows: ASTM A29/ A29m-2015 (hot forged and cold processed carbon steel and alloy steel bar).

It has high hardenability, no tempering brittleness, good weldability, little tendency to form a cold crack, good machinability, and cold strain plasticity. Generally used in quenching and tempering or carburizing state, used for manufacturing small and medium-sized automobile, tractor engine and gear in the transmission system, oil drilling and metallurgy open mine cone bit teeth and teeth body, manufacturing steam turbine gear whole rotor internal combustion engine connecting rod valve section forgings. At the same time, the surface of 8620 steel after carburizing heat treatment has relatively high hardness, wear-resistance, and contact fatigue strength, while the core retains good toughness and can withstand high impact load. It can be used as automobile bearing, spindle, gear, mechanical parts, and other impact-resistant, wear-resistant workpieces.

Otai provides the grinding, milling, polishing, turning, drilling, and other machining services as your required tolerances and size.

Otai does not act as a material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problem without any hesitation on responsibility. We are welcome to your kind inquiry.