Related Products Flat diamond grinding wheel 6” x 1.5” 360 grit $180.00 excl GST 8″ lap backing plate with one threaded adapter $140.00 excl GST Electroplated diamond core drill, 20mm dia. 8mm shank. $28.00 excl GST Quantity Add to cart Product added to wishlist. Add to WishlistProduct added! Browse WishlistThe product is already in the wishlist! Browse Wishlist Share Product code: 450020 Category: Core drills. Tags: core drills, Diamond drills, glass, glass work, lapidary.