Stainless steel ball : SUS304/SUS316/SUS440/SUS440C There are two main technical considerations when purchasing balls: (1) Type of Material. (2) Dimensional accuracy required. If you need more information, please visit our Website: www.holo-pack.com.tw Holo Pack manufactures/distributes precision balls in variety materials, specifications, and tolerances. Precision balls are suitable for all applications and industries.