Spring threading aid

Hi I've been searching for a device I've seen on various you tube channels. When tapping small sizes in the milling machine, people often use a spring loaded point which puts vertical load on the tap. Then with a small wrence they can turn the tap whilst the device pushes the tap into the hole. They look useful but can't find them anywhere on line. I wondered if anybody can point me in the right direction.

Google spring tap guide you will be spoilt for choice

RDG sell them, but easy to make

I think ARC list them too.

If you make one it's worth making the plunger double-ended and reversible, with a point at one end, a shallow centre-drilling the other. That so you can use it with taps that have a blunt point instead of centre-hole at the top, typical of small diameter taps.

Hi Philip,

I have the smallest one of the tap guides from ARC and they work very well. You can of course make one if you don't want to buy one.

Thor

Its main purpose is to keep the tap aligned, not to force the tap into the work. It may help start the thread, but that is all.

A tap wrench is the tool to use for screwing in the tap, not a “wrence’ (ordinary wrench, likely an adjustable spanner?). Use of the proper tool allows more than adequate pressure to be applied equally on both sides of the axis.

This is a double ended spring centre I made to use in my mini-mill. It has about 15mm of travel and you can fit either end in the drill chuck depending on whether you need a male or female centre. It's made from 8mm mild steel bar, although it could be scaled up for people with BIGGER machines.

A trick I learnt as an apprentice for smallish threads was to have the working tap drive square part way into the wrench and put another tap from the same set with the threaded end in the drill chuck, lightly fingertight, don't use the chuck key.

Put the end of the working tap into the job, bring the other backwards tap to it to engage in the wrench and nip the wrench up. Start the thread going, the backward tap will guide the working tap into the hole until enough thread has been cut to be stable. If on a mill this relies on not moving the X Y axis of course!

A teslescopic guide with changeable springs is an advantage so you can use it for a range of tap sizes. (An M2 tap in brass requires far less force that an M10 tap in steel)

Paul.

Edited By Paul Lousick on 01/12/2020 08:31:25

I don't bother with a sprung one just have a bit of bar pointed at one end and ctr drilled at the other that can be held in chuck or collet and apply pressure as needed with the quill lever while turning tap wrench with the other hand.

Thanks for the rapid replies. Must admit I hadn't thought about making one but as said they look pretty easy to make.

Thanks again Phil

Type Making a tap follower into the Youtube search box brings up a miriad of video's on making one.

regards

Hi Philip,

There is a description on how to make a simple tap-guide at the end of this article.

Thor

The important thing is to align and support the tap. In this way, the thread should be perpendicular to the work, and the Tap is less likely to break.

Taps will stand a lot of cyclic torsional loads, but fail very quickly in bending. Sometimes, once is enough!

My method, in the Mill, is to align / support the Tap with a spring tool, and to drive it with a Tap Wrench. As the travel of the spring support is used up, it is advanced to provide support, and prevent bending.

In the lathe, my sliding Tailstock Tap Holder, using ER collets, provides both alignment and support.

Should the Tap jam for any reason, the parallel shank slips within the collet, saving the Tap.

Howard

I used to do that (still have the piece of bar) but sometimes I found I needed 3 hands.

When I require a third hand I attach a small bungee on the quill lever.

Also when metric screw cutting on the lathe the leadscrew split nut lever is held down with a bungee as lost position once when nut got disengaged when reversing for next cut.

Edited By Windy on 01/12/2020 16:46:11

Most of the commercial tap guides have a reversible spindle. One end has a female taper, the other a male taper. Thatway it can be used with any tap. There are many on-line sources.