.938 - 16 UN tap size?

I have been very successful with my first home built CNC machine, I can cut .025 traces on circuit boards.

I plan to make another machine, the Ball screws I plan to use are from ROTON but I would like to make the Flange myself as they cost more than the ball nut.

What is the tap size for .938 - 16 UN is it 15/16th 16 tpi I don't find the UN anywhere on the tap selections.

Link:
5/8 X .200 Right Hand Recirculating Lead Screws & Nuts for Power Transmission - Roton Products, Inc.

Suggestions for additional suppliers of ball screws and ball nuts especially machined ends on the screws welcome.

The machine I would like to make now is a simple circuit board drilling machine that would use a dremel tool for a spindle.

You can buy a 15/16-16 tap.

Special pitch taps - 17/32 to 1-1/8 - 1000's of specials in stock and most custom taps made in 24 hours. - special threads.

UN is unified national, the thread form, and UN is the common US standard form. The tap might be called 15/16-16 UNS for unified national special.

Using a Dremel suggests to me that you do not plan on accurate results and you do not plan to drill small holes. Small CB drills will probably not last long in a head with loose plain bearings and an inaccurate chuck. A Dremel, in other words.

I have a commercially made CB drilling machine that uses a Dumore automatic air feed high speed drilling spindle. It would be easy to add stepper motors to the two hand cranks and convert it to CNC. Too bad it is so heavy and hard to pack and ship. If you want to drive here and pick it up, $250.

Larry

metron9 said:

What is the tap size for .938 - 16 UN is it 15/16th 16 tpi I don't find the UN anywhere on the tap selections.

Click to expand...

Tap drill size for .938-16 (15/16-16) would be 7/8" or .875"

The 16 tpi thread data is easy for me to remember as I tap lots of 3/8-16 holes in various parts. Tap drill size for 3/8-16 is 1/16" smaller than nominal thread size which works out to 5/16". For all 60° v internal threads with 16 tpi, the minor diameter will be 1/16" smaller than whatever the nominal thread size may be.

The thread pitch of any single lead thread is 1/tpi. In this case, 16 tpi equals 1/16, which obviously is 1/16" or .0625" Again, easy to remember when cutting threads on the CNC lathe.

You can buy that through MSC, I buy three to four 15/16-20 taps a year through them.