Who has one of these tapping fixture tools ?

Hi Jo,

Your first paragraph connects nicely with the second paragraph. The words 'relatively square' fits the bill for the tapping fixture which we sell. Reasons/examples as follows:

SMEE members in London did a 'group purchase' of six pieces one year. I explained to them that this product is a bit like marmite. There is a particular feature, which you like or hate.

The aluminium box section arm through which the spindle goes through in clamped to the column. After clamping, it still allows the arm to move side to side, even though it stays locked on the column. Depending on your point of view, this is a good thing especially if you do not have a steady hand and you are using very small and fine taps. If the arm is locked and does not move, and if the hole in the work piece to be tapped is not square to the tap and held rigid in a vice or clamped down, then the probability of the tap breaking are high. The converse - 'not a good thing' for the arm to move side to side, which could also break the tap for different reasons.

However, once purchased, some of the users did not like the fact that the arm moved from side to side, even though this was explained at the exhibition, pre-sell. These got re-sold internally to other members who liked the idea of the arm moving from side to side!

This product was initially introduced by Micro-Mark in the U.S.. The original spindle as supplied by various traders, is not perfectly round. Hence we buy the steel which is used for the spindle locally, and put on the JT taper on one end, and a better hand wheel on the other. It is smoother, and 'as round' a stock as you can get. However, for certain customers who demand 'high precision' this is still not good enough for under £50.00.

Hence the phrase 'relatively square' was born. At the end of the day, we still believe that the threads made using this fixture will be more accurate than tapping free-hand. This is an economical solution, which may suite some customers requirements and not others.

If you need a tapping fixture or not is a different question, but even by appearances, it doesn't fall into the 'Chocolate Fireguard' category

Ketan at ARC

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Delighted to hear it, Ketan

Personally; for larger sizes I use the technique described by Tomfilery

For tiny threads [typically in plates] a tap-holder can be made to fit the Cockmakers/Watchmakers Staking Set. [same device in different sizes].

MichaelG.

Another method I use for getting taps square

is very simple indeed drill a hole the clearance dia of the tap

in a scrap piece of metal clamp it down with tool makers clamps

over the hole to be tapped and bobs your uncle use that as a guide

works very well

Best Wishes Martin

A piece of flat steel bar with a series of holes in it at various common tap ODs works well. Mine is about 1" thick by 2" wide and 4" long, machined or filed flat on the bottom.