I have had a cheapo "T" wrench for years, it has 3 adjustable collets to fit the various sized taps.

I use the same Eclipse wrenches as Clive. You can, or could, buy a set of spring loaded guides with both male and female locations for the taps, to fit into a drill chuck and steady the end of the tap as it starts and progresses into the hole.

By progressively lowering the drill chuck, the Tap can be guided all the way to the bottom of the tapping..

Howard

I use an Eclipse pin chuck for drilling small holes and tapping. It has collets which hold drills from 0.75mm – 2.5mm.

The collets have 4 jaws and suited for holding the square end of small thread taps. A hole thru the base is used for a torque bar when tapping threads. Drill chuck loosened and used to guide tap.

Paul.

Edited By Paul Lousick on 04/08/2020 12:29:29

E141 is the smallest "standard" size. Old ones, found on eBay etc, tend to be better made than new ones.

The pin chuck, as recommended by Paul, grips best for very small taps (12-16BA sort of size.)

Rod

If you can source an eclipse or similar small tap holder then an easy way to get round the need for a centre is to grind a small flat on the side of the tap for the holder to key against – I do this by using the corner of the wheel on an off hand grinder. The tap itself is held loosely in the drill chuck to act as a guide as here – works very well and efficiently – two handed drive.

All the 8BA threads on the two cylinder blocks for this corliss engine was done as such using just the one tap.

If you can't source a small holder then a thin disc, knurled on the periphery with a grub screw through to key the tap is also very efficient.

Hope that helps some Dr G

Ramon