Carbide Sizing Balls, 7/16 inch High-quality tungsten carbide balls are designed for consistent hole sizing and longevity.
Each ball is precision machines to K-line's strictest quality control standards, guaranteeing a hardness rating of 91+ on your Rockwell A scale.
Be sure to order carbide balls .001 larger than your desired finish guide inner diameter due to material flowback that occurs when pressure forming bronze.