How to Cut Holes in Steel Tube Walls

Place the tube into a tilting vise attached to a drill press with the cutting area pointed upwards. Tighten the jaws of the vise onto the tube sides, twisting them closed slowly to avoid denting the tube in the process. Wiggle the tube slightly in the vise to ensure that it's held securely.

Mark the cutting circle onto the tube with a pencil. Place a second mark in the center of the circle.

Put on a pair of safety goggles to avoid injury from metal scraps while cutting the hole.

Attach a hole saw in the size of the hole you wish to create in your tube onto the drill press. Position the tube beneath the hole saw, tilting it at an angle if you need to drill an angled hole into the side of the tube for a mitered pipe connection with a second pipe. Lubricate the surface of the tube where the hole saw will cut through using cutting fluid to prevent the saw from overheating, or the teeth of the saw from breaking of on the tube.

Place the bit in the center of the hole saw on the marked center of your drilling area, and then press down on the drill, plunging the saw into the side of the pipe. Drill through the tube with the hole saw, using the vise to to keep the pipe steady as you do so. Add more cutting fluid as needed to keep the saw lubricated should the present fluid run out on the surface of the pipe.

Remove the cut metal plate from the tube after you complete the hole. Wipe away the cutting fluid and the metal shavings from the tube with the rag.

Clean off the edges of the hole with a fine-toothed file to remove any burrs left due to the cutting process. Scrape the file downwards over the rim of the hole, smoothing away any jagged edges. Take care not to sharpen the hole while smoothing. Wipe the tube clean again, both inside and out and then remove it from the vise.