There are three tool options to consider when drilling large-diameter holes in thick steel: twist drill bits, hole saws and annular cutters. 1. Twist drill bits. Especially in steel thicker than ...

For large holes, a hole saw gets the job done ... drill bit from wandering as it bores through the sheet metal. Step drill ...

Spade bits remove a large section of material ... with a distinctive stair-step profile. Each "step" is one drill size larger than the next. This lets you drill a hole exactly as wide as you ...