SKF, founded in Sweden in 1907, is a global leader in friction management and bearing solutions. 
The SKF HK series is a needle roller bearing with an open stamped outer ring and no inner ring. It features an ultra-thin cross-section, strong radial load capacity, compact and economical structure, and is suitable for various heavy-load operation scenarios in confined spaces. It is available in sealed and oil-injection hole styles. It can be directly used with hardened grinding shafts, eliminating the need for additional inner rings. It is widely used in construction machinery, automation equipment, and transmission mechanisms. 

The SKF BK series of sealed bottom-type drawn cup needle roller bearings feature an integrated deep-drawn, quenched, thin-walled sealed outer ring with a built-in tail rib to isolate dust and impurities. They offer compact radial dimensions and excellent radial load capacity. The sealed models are pre-filled with long-lasting grease and can be directly press-fit into the housing, simplifying assembly. They are suitable for rotary support applications in electric tools, hydraulic components, automotive parts, and other narrow spaces prone to dust contamination.