Mechanical structural alloy steels are those steels suitable for the manufacture of machinery and mechanical parts. It’s the addition of one or more alloy elements based on the high-quality carbon steel that improved the strength, toughness and hardenability of steel, usually put to use after heat treatment. Alloy bearing steel and alloy spring steel is the main mechanical structural steel, which also including tempered alloy steel, surface hardening alloy steel and cold plastic forming alloy steel.

Alloy bearing steel and spring steel is characterized by its easily quenching and improved mechanical properties after tempering, can be used to manufacture all kinds of machinery parts, not only has good tensile strength, elastic/long fatigue limit, elongation rate, such as mechanical properties, impact value at the same time there good casting, forging and machinability, mostly used in manufacturing shaft, gear, bearing, screws, nuts for automobile motorcycle parts, and other important mechanical parts with surface carburizing hardening.


WIHO metals offer the steel material that can be used for gears and bearings. Gear steel is the steel used in the manufacture of vehicle gear, industrial gear, and other gear transmission parts. The gear should meet the requirements of good toughness, long life, impact and wear resistance, small deformation, high precision, the core of high toughness, gear steel usually use 0.15%~0.25% of low carbon steel containing C content for surface carburizing or nitriding treatment.

Bearing steel is a kind of high carbon chromium steel that used in the manufacture of the rolling bearing ball, roller and sleeve, etc. Wiho metals offer the steel material that can be also used for precision measuring tools, cold punching die, machine tool screw, such as punching die, measuring tool, tap and diesel engine oil pump precision parts.

Gear Steel and Bearing Steel Grades

Japanese JIS G4052 Gear steel Alloy steel SNCM415, SNCM420

SNCM220, SCM440

SCM420, SCM415

S45CBD, S45C

Bearing steel Cr steel SUJ2

SUS 440C, 316


SAE J1268

Gear steel Low carbon steel,

Case Hardening carbon steel

1020, 1026, 1116

4140, 4130, 4340

8615, 8617, 8620, 8622, 8720, 8822, 9260

Bearing steel High-carbon Cr steel,

Case hardening bearing steel

AISI 51100

AISI 52100


AISI 316

German DIN/EN 10084、

DIN 17210

Gear steel Cr-Mo steel DIN 15CrMo5
Bearing steel Cr-Mo steel 100Cr6


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