Related Products Diamond core drills 4.5mm dia $8.00 excl GST Spherical radiused grinding wheel 6” x 1.5” 600 grit $175.00 excl GST 12″ economy sintered continuous rim lapidary blade. 300 x 1.2mm $100.00 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 TweetPin It Product code: 450020 Category: Core drills. Tags: core drills, Diamond drills, glass, glass work, lapidary.