- Combined drill and countersinks perform two operation in one, with a drill point followed by the countersink portion. These tools are often used to make female centers for parts to be held on lathes. Our combined drill and countersinks are always double-ended and also come in a standard or a bell style, which has a second diameter countersink portion. The standard included angle is 60 degrees, and they are available in a variety of materials and coatings. Sizes range from #00000 to #8. Also see our #1-#5 combined drill and countersink sets, available in handy wooden tubes. These countersink sets are available in high speed steel or solid carbide.