Any decent brand-name carbide drill bits, provided that they’re intended for drilling metal instead of masonry (masonry drill bits have completely different construction).

You should know that carbide drill bits should never be used with a handheld drill motor, only with a drill press or milling machine, or metal lathe, because they’re brittle and may shatter if they’re used improperly.

You should also know that they’re difficult to grip with any conventional drill chuck because of their great hardness and high polish.

Last, you should know that the preferred way of drilling hardened steel is to spot-anneal it where you plan to drill it, then drill through the annealed spot with an HSS drill bit instead.

Oh, yes – you also need to use a great deal of feed pressure with carbide drill bits to keep them digging under the hardened steel surface. The same is true with HSS but to a lesser degree. Never permit a drill bit to burnish the bottom of the hole, always keep it digging when you’re not retracting it to clear chips.

Leave A Comment

Receive the latest news in your email
Table of content
Related articles