Which drill would you use to bring a punched hole in steel plate to size?

Which drill would you use to bring a punched hole in steel plate to size?

• A. Twist drill
• B. Center drill
• C. Core drill
• D. Spot drill

Answer: (C)

When you need to bring a punched hole to its final size, you want a tool that can remove material from inside the established bore to the exact diameter and leave a true, clean hole. A core drill is designed to cut along the inner surface of the hole and remove the remaining core material, finishing the bore to the precise size you need in steel plate. The other drills serve different purposes: a twist drill is for creating new holes and can’t reliably size an existing hole to a precise diameter; a center drill and a spot drill are used to start and position holes (to form a center or a locator point), not to finish and size the bore.

When you need to bring a punched hole to its final size, you want a tool that can remove material from inside the established bore to the exact diameter and leave a true, clean hole. A core drill is designed to cut along the inner surface of the hole and remove the remaining core material, finishing the bore to the precise size you need in steel plate.

The other drills serve different purposes: a twist drill is for creating new holes and can’t reliably size an existing hole to a precise diameter; a center drill and a spot drill are used to start and position holes (to form a center or a locator point), not to finish and size the bore.