The replacement half-ball is made from implant grade 316LVM stainless steel by Body Circle Designs. Half Balls are not counterbored and can fit any barbell with the right thread size. All 16g ends have a #000-120 thread size and all 14g-8g ends have 1.2mm threading. All parts are hand polished to a mirror finish. These are available in the 5/32" size only.