The Drill Press Tube Notcher: Clean Joints in Round Tube

Anyone who has tried to join two pieces of round tube knows the problem: for the joint to fit, one tube has to be cut with a curved saddle, a fishmouth, that wraps around the other. Do it by hand with a file or grinder and you get hours of fitting and a joint full of gaps. The drill press tube notcher solves it in seconds by using a hole saw to cut that saddle cleanly and repeatably. It is one of the most satisfying jigs you can add to a drill press, and understanding what a tube notcher is, how it works, and how to use it safely is the key to clean tube joints. This guide covers it.

A drill press tube notcher is a jig, mounted on or clamped to the drill press, that holds a piece of round tube at a set position and angle while a hole saw in the chuck cuts a curved notch, a fishmouth, into the end. That curved cut matches the outside of the tube it will join, so the two pieces meet with a tight, weldable saddle joint. The tube notcher turns the drill press into a purpose-made coping tool for tube, doing accurately and quickly what is miserable to do by hand.

How the tube notcher works

Understanding the setup shows why it works so well. The jig clamps the workpiece tube in a vise or holder that positions it at the correct height and, crucially, at the angle of the intended joint (a T-joint at ninety degrees, or an angled joint tilted to match). A hole saw whose diameter matches the tube being joined is mounted in the drill press chuck. When you feed the spinning hole saw into the clamped tube, it cuts a curved notch exactly the shape of the mating tube’s surface. Because the hole saw diameter equals the joining tube’s diameter, the resulting saddle wraps the other tube perfectly, which is the whole trick.

Why it beats hand notching

The payoff over freehand work is dramatic. The notch is accurate, matching the mating tube’s curve so the joint closes up tight for a clean, strong weld, instead of the gappy fit a hand-ground notch gives. It is repeatable, so every joint in a frame comes out the same, which matters when you are building a structure with many identical joints. And it is fast, cutting in seconds what takes ages with a file or grinder. For anyone building tube frames, roll cages, railings, or furniture, a tube notcher on the drill press is a genuine leap in both quality and speed.

Setting it up correctly

Good results depend on getting a few things right. Match the hole saw diameter to the tube you are joining, not the tube being notched, since the saw cuts the profile of the mating tube. Set the jig’s angle to the joint you want, ninety degrees for a T, or the offset angle for a mitered joint, and confirm it before cutting. Clamp the workpiece tube solidly in the notcher’s holder so it cannot shift or spin, and secure the notcher itself to the drill press table. Run the correct low speed, since hole saws, especially in steel, need to run slow to cut without burning, and use cutting fluid on metal.

Using it safely

A hole saw in tube can grab hard, so technique and holding matter for safety. Clamp the tube absolutely securely, because a hole saw biting into a loose tube will spin it violently; the notcher’s own clamp does this, and mounting the notcher in or alongside a drill press vise bolted to the table keeps the whole setup anchored. Feed slowly and steadily, letting the hole saw cut rather than forcing it, since forcing makes it grab and can snatch the tube. Back off to clear chips and keep the saw cool, use plenty of cutting fluid in steel, and keep hands well clear of the hole saw. Wear eye protection, since notching throws chips.

Conclusion

The drill press tube notcher solves the miserable job of coping round tube by using a hole saw to cut a clean, accurate, repeatable saddle joint in seconds. It works by clamping the tube at the right angle and running a hole saw sized to the mating tube into it, producing a fishmouth that wraps the joining tube for a tight, weldable fit far better than any hand-ground notch. Set it up by matching the hole saw to the joining tube, setting the joint angle, and clamping everything solidly, then cut at low speed with plenty of fluid and hands clear. For anyone building tube frames, it turns the drill press into a fast, accurate coping tool.

Three takeaways: a drill press tube notcher uses a hole saw to cut a clean fishmouth saddle joint in round tube; match the hole saw diameter to the mating tube and set the jig to the joint angle; and clamp the tube solidly and cut slowly with cutting fluid, since a hole saw in tube can grab hard.

Frequently Asked Questions

What is a drill press tube notcher? A jig mounted on the drill press that holds round tube at a set angle while a hole saw in the chuck cuts a curved saddle notch (a fishmouth) into the end, so the tube fits tightly against the tube it will join.

How does a tube notcher work? The jig clamps the tube at the joint angle, and a hole saw sized to the mating tube cuts a curved notch shaped like that tube’s surface. Because the saw diameter equals the joining tube’s diameter, the saddle wraps it perfectly.

Why is a notched joint better than a hand-ground one? Because it matches the mating tube’s curve for a tight, gap-free fit that welds cleanly and strongly, it repeats identically across many joints, and it cuts in seconds rather than the long fitting a file or grinder needs.

What size hole saw do I use? One matching the diameter of the tube you are joining, not the tube being notched, since the saw cuts the profile of the mating tube. That is what makes the saddle wrap the other tube correctly.

What speed should I run for tube notching? A low speed, since hole saws, especially in steel, need to run slow to cut without burning or dulling. Feed slowly and steadily, use cutting fluid on metal, and back off to clear chips and cool the saw.

Is tube notching on a drill press dangerous? It can be if the tube is not held securely, since a hole saw can grab and spin a loose tube violently. Clamp the tube solidly in the notcher, anchor the notcher to the table, feed gently, and keep hands clear.

References

• VintageMachinery.org, machine tool references and literature. http://vintagemachinery.org
• Jacobs Chuck Manufacturing, Mounting and Removing Chucks. http://www.jacobschuck.com/uploads/ueditor/file/20200604/1591240204146153.pdf