Related Products Sandblasting gun spare tips $8.00 Sintered diamond point, ball shape 4mm dia, 3mm shank $20.00 12 x 12mm diamond bands, soft type 400 grit $16.00 Quantity Add to cart Product added to wishlist. Description 12mm x 12mm diamond bands are an alternative to solid diamond points. They fit on an expanding mandrel with a 3mm shaft. The diamonds are electroplated to a material substrate. 400 grit. Add to WishlistProduct added! Browse WishlistThe product is already in the wishlist! Browse Wishlist Share Product code: 401400 Category: Diamond point sets and bands. Tags: diamond points diamond bits, glass work, Grinding wheels, lapidary.