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I've found myself tapping and threading a lot lately, and doing so with hand taps and dies. What would be the next step up from using a drill-press to cut holes for tapping, and a lathe for turning parts to diameter for threading?

What are options for making this easier and more precise short of a 6-figure screw or CNC machine?

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  • $\begingroup$ In some cases, you can just load a tap into a drill press at low speed and drive it into a pre-drilled hole. It'll catch and drive itself in. Just keep your hand on the switch to stop and reverse. It will let you tap holes very quickly. I believe that it's possible to do something similar for external threads. $\endgroup$ – Dan Jan 21 '15 at 0:49
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For tapping threads, there are a few steps between free hand tapping and fully automatic machines. Which one is right for you will depend on the material you're tapping, the size of the threads you're tapping, and how large your production run is.

The first step would be to buy a guided tap wrench, which is a regular hand tap wrench with a bushing you can put on the top and chuck into a drill press (or mill) or lathe. This helps keep your tap square to the workpiece and also lets you apply a little pressure with the quill.

If you want to get into power tapping (And need more precision than a cordless drill with the clutch turned down,) there are reversing tapping heads you can attach to a drill which reverses the tap out when threading is complete. These are available for drill presses or hand-held drills. They run around \$500-$1,000. here's another style of tap chuck called a tension compression chuck, which allows a little vertical give but I believe that is only of much use if your spindle is computer controlled.

If you want a more robust solution and have some money, there are tapping presses that start at around $3,000. It's not quite 6 figures, but they aren't cheap.

Depending on what you are making, self threading screws may also be a valid option. There are a wide variety of types that work in different situations.

As for external threads, after die cutting, the only cheaper method I'm aware of is roll threading. This requires a dedicated machine that is relatively expensive unless you're working on very small threads.

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LIMITED SCOPE: this answer is limited to the tap aspect ... it's a way to mitigate the tap-hole alignment concern.

If you already have the drill press and piece, you can put the tap in the drill press somewhat loosely in order to get the tap in the first 1/4" or more (presuming a countersunk hole), from which you can do the rest by hand. This reduces the lining-up-of-the-tap-with-hole aspect which often requires special care & time.

Video demo: https://www.youtube.com/watch?v=KmtbzL8YlxM

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    $\begingroup$ Also bare in mind there are taps with varying length tapers: bottoming, plug and taper. In some cases a taper has worked for me in a basic pillar drill as mentioned. $\endgroup$ – CL22 Jan 21 '15 at 8:52

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