Specifications:
Ball Diameter: 4.5mm, 4mm
Material: 304 Stainless Steel

Package Contents:
50 x 4mm Precision Balls
50 x 4.5mm Precision Balls

Descriptions:
Bearing balls are useful in valve pumps, and spray paint bottles for agitation, sprinkling systems, appliance components, casters, drawer slides, locking mechanisms, semi-precision bearings, and lots of other industrial and consumer products.
Notice: Please confirm the Ball Diameter you are ordering.
(To better understand each type of commonly used stainless steel and its properties, see the following descriptions.)
440C Stainless Steel is a high carbon martensitic stainless steel. It has high strength, medium corrosion resistance, good hardness, and wear resistance
420 stainless steel is a martensitic stainless steel, with certain wear resistance and corrosion resistance, high hardness, etc.
304 Stainless Steel is the most widely used stainless steel. It is austenitic stainless steel and has a higher corrosion resistance than ordinary steel.
316L Stainless Steel is also austenitic stainless steel. It offers higher corrosion resistance than 304.
201 Stainless Steel is the least expensive type of stainless steel. It is tough in cold environments but has lower corrosion resistance. 201 stainless steel is the preferred choice for applications that require low cost, high durability, and no concern for exposure to corrosive elements.