Related Products 6″ lap backing plate with one threaded adapter $125.00 excl GST Quantity Add to cart Product added to wishlist. Description One 6″ lap backing plate with one threaded adapter. 5/8″ and 3/4″ right hand threaded adapters in stock, but 1″, 1/2″ right hand and 1″, 3/4″, 5/8″ and 1/2″ left hand thread can be ordered. Reviews (0) Add a Review Add to WishlistProduct added! Browse WishlistThe product is already in the wishlist! Browse Wishlist Share Category: Tools. Tags: diamond tools, Grinding wheels, lapidary, laps.