Material for raceway rings and roller elements of NSK wheel bearings

NSK offers customers various types of steel for raceway rings and rolling elements according to their usage conditions and locations, including its most popular, high quality steel SUJ2 (SAE52100).

SUJ2

For many years NSK has been striving to improve the quality of steel with the cooperation of bearing-steel makers. Through advances in the technology and facilities of steel mills and accumulated test data on NSK bearing life, NSK have developed a high-quality, long-life bearing steel. This steel is a long-life material that is largely free of harmful non-metallic indusions, and it is frequently adopted in hub unit bearings. it is used for the rollers and contact balls, the outer and inner rings of HUB 1 (BWD), the outer ring of HUB 1 (KWD), and as the standard material of the inner rings for HUB2 and HUB3.

SUJ2 (EP steel)

Based on NSK's proprietary evaluation method, the technology for mass production of high-purity steel was established, and resulted in SUJ2 (EP steel), which has a subsurface-originated roller fatigue life that is even longer than that of SUJ2.

This material is used for the outer and inner rings of HUB 1 (BWD) and the inner rings of HUB 1(KWD), HUB2, and HUB3.

S53CG (in compllance with SAE1055)

This is an induction heat-treated material, which can be inexpensively die-forged into complex shapes. It is mainly used for parts such as axle components, which require impact-load resistance. Induction heat treatment allows NSK to control the hardness of the component parts. This material is used for the outer rings of HUB2 and 3, and the flanged inner rings of HUB3.

Carburizing Steel (SCr420H)

Carburizing allows proper hardening depth, a dense structure, and appropriate surface and core hardness of materials in order to extend the fatigue life of NSK bearings. This material is used for the inner rings of HUB 1(KWD), HUB 2, and HUB 3.

Hi-TF steel

Hi-TF steel was developed in order to extend service life under conditions in which lubricants become mixed with foreign matter, providing excellent resistance against wear and seizure at a reasonable cost. This material is used for the inner rings of HUB 2 (KWH).

New-TF steel

New-TF steel has the advantage of long service life under conditions in which lubricants become mixed with foreign matter, maintaining excellent resistance against wear and seizure at a reasonable cost. This material is used for the inner rings of HUB 2 (KWH).

Cage material

The cage for NSK wheel bearings is made from Nylon 66 with glass fiber. Pressed cages for HUB 1 (KWD) are made of low carbon steel.

Now that improved automotive safety has become a primary goal of manufacturers, the Antilock Brake System (ABS) has beome widely used in automobiles, ensuring safe braking on slippery and icy roads.

NSK has been active in the research and development of ABS-related products.