A 100mm long by 152mm diameter 9° sill block with the option of also moulding a corner radius in the one pass. The block is made from aluminium to keep the weight and the inertia to a minimum. Fitted with cutting spurs at the top and bottom, cutting knives in two of the slots and the option of radius cutters and limiters in the other two. All four slots are grooved for additional security. The standard bore is 30mm, 1.1/4" bore is available as a special order. 6mm radius cutters and limiters are available separately, others are available to order.