When preparing a hole for reaming larger than 1/2-inch diameter, what should be the difference in size between the drill and the reamer?

When preparing a hole for reaming that is larger than 1/2 inch in diameter, it is essential to leave an appropriate allowance for the reamer to ensure proper cutting and a smooth surface finish. The correct difference in size between the drill and the reamer should be around 1/32 inch to 1/64 inch.

This sizing is critical because reaming is intended to refine an already drilled hole by enlarging it to a precise diameter and improving surface finish, so it requires a smaller allowance compared to other machining methods. A difference of 1/32 inch allows the reamer to engage effectively without excessive material removal or risking tool wear. The lesser allowance of 1/64 inch provides an even tighter tolerance option when precision is demanded.

This precision helps achieve accuracy in applications where tolerances are critical, which is a key aspect of manufacturing processes. Proper sizing ensures enhanced efficiency in the reaming operation and supports the overall quality of the finished product.