A Tapping Stand having Automatic Feed, Harold Hall
The feature that makes this tapping stand differ from most, if not all others offered
for the home workshop, is that it automatically feeds the tap at the correct rate
for the pitch of the thread being cut. This eliminating the need for the user to
apply any down feed pressure to get the tap started.
The main advantages are:-
1. The thread can be made using just a plug tap, taper taps not being required.
2. No partial threads at the start as often occurs when using a taper tap as the
thread is complete from the first thread. This is not that important with deep threads
but very beneficial when tapping thin sheet metal.
3. The controlled feed mechanism can be held in the tailstock drill chuck and the
feature is then also available for holes being tapped on the lathe.
4. The feed mechanism uses a normal screw to control the feed rate so there is no
need to turn and thread parts, except where screws to the required pitch are not
5. The feed mechanism is not diameter dependant. Typically therefore, a single feed
mechanism for 40 tpi will suit all diameters of Model Engineers threads having that
6. Like all taping stands it produces a thread that is, with a little care, perpendicular
to the surface being tapped.
7. In manufacturing terms it is very easy to make.
Automatic Feed Tapping Stand
M3 to M8 Thread Tap Holders and Feed Mechanisms
Tapping Drill Sizes
When tapping using this tapping stand or purely by hand, do use a drill size that
gives between 60 and 70% thread depth for all but the most demanding applications,
See Recommended Drill Size tables
The design drawings for this can be found in my book