Diamond Standard Lap was Quality diamond replacement disks 6", 8" Facet Lap Machine or other lapidary equipment using a 6" Master Lap. Available in a comprehensive series of grits for all your sanding, shaping and polishing needs. Secured to a master lap by mechanically clamping them. They are not pressure sensitive backs. Grinding and shaping lapidary cabochons ;Grinding and shaping stone for intarsia projects ;Create gemstone perform Sanding and pre-polishing. 1/2" Standard Hole size