2 Taps Needed.

[MikeinSC]

Is there anyone that would be willing to cut 2 taps? One would be 6.5 x .5 and the other 7.5 x .5, plug or bottom type as they will be used on a through hole. The taps will be used for working with acrylic and done by hand. No need for special coating or special alloy that I can think of.

I make custom pens and am hoping to do some horse trading. After all, Christmas is coming up and a handmade pen could be the perfect gift for that hard to buy for person in your life.

Mike

 

[mksj]

Haven't made taps yet, would be an interesting project. These sizes are a bit difficult to source, but metric taps in these sizes can be purchased at http://www.silverpenparts.com/pb/wp_dfdf98a0/wp_dfdf98a0.html

You can also check some of the on-line vendors through Amazon, many ship from Asia and have difficult to source metric threads.

 

[Andre]

If your working in Acrylic you can probably make one with mild steel, if your lathe can thread metric. The flutes can probably be cut using a rotary tool if you don't have a mill.

 

[george wilson]

You don't need to flute taps. I have made many. In the 18th. C.,commercial taps were made by just filing the cutting ends into a square that tapered down below the depth of the threads. Triangular works just fine also. I'm always making odd thread taps for repairing very old mechanical devices. I even duplicate the forms of the threads.

 

[markba633csi]

Hi George- could you explain about filing the cutting ends into a square? I'm not sure what you mean and what shape you end up with...
Mark S
Mt. View, Ca

 

[Arrak Thumrs]

Mike,
Did you decide to order those linked to taps? If not, I could make you those out of O1. My shop has heat-treat capability.

Mark,
I believe that George simply means this. If the tap was stood up vertically, the cutting end would look like a pyramid. The four facets are flat machined, but they create a cutting edge where the thread intersects the angle.

 

[Arrak Thumrs]

So... I like a good project. Taps are something I don't make often, and I wanted to prove to myself I could make one decently. Here is my 6.5 x 0.5 mm:


Result in aluminum:


Result in mild steel:


I expected to stone the flutes, but it worked quite well with little effort. It is O1, hardened and tempered. The shank was polished, but nothing beyond that. I suspect it would cut even easier with a grinding / stoning of the flutes to sharpen the cutting edges. As is, though, it is plenty usable.

The pitch diameter was cut according to the formulas in Machinery's Handbook. It would be interesting to have a part to try with the resulting, threaded hole. See how the fit turned out with a matching part. The tap was made to D5 tolerance.

Regardless if the OP needs it, the project was a worthwhile challenge. I'm glad I did it. Hopefully this post will encourage others to make that odd piece of tooling needed in the shop!

 

[REdington]

This is one I made from a piece of metric acme threaded rod. I use it to tap Delrin blocks for zero backlash for the 3D printer I make.
I turned a taper on the end and then mill the flats on the mill with a carbide endmill. It works very well in Delrin.









Rodney

 

[MikeinSC]

So... I like a good project. Taps are something I don't make often, and I wanted to prove to myself I could make one decently. Here is my 6.5 x 0.5 mm:


Result in aluminum:


Result in mild steel:


I expected to stone the flutes, but it worked quite well with little effort. It is O1, hardened and tempered. The shank was polished, but nothing beyond that. I suspect it would cut even easier with a grinding / stoning of the flutes to sharpen the cutting edges. As is, though, it is plenty usable.

The pitch diameter was cut according to the formulas in Machinery's Handbook. It would be interesting to have a part to try with the resulting, threaded hole. See how the fit turned out with a matching part. The tap was made to D5 tolerance.

Regardless if the OP needs it, the project was a worthwhile challenge. I'm glad I did it. Hopefully this post will encourage others to make that odd piece of tooling needed in the shop!

I did not order anything yet. The tools are a necessity for making certain pens and there is no other way around it. I just can't come to grips with paying the prices just yet.

I don't have any parts on hand that will fit the 6.5 but do have one to fit the 7.5. If you also made one of those, I can send you that piece to test it out.

The tap looks good.

 

[Arrak Thumrs]

Mike, I know next to nothing about pen making so went searching. What threads into a M6.5 x 0.5 or M7.5 x 0.5 tapped hole? Is it a Jowo nib for a fountain pen? I get the impression the mating part is purchased.

The tap I made is single-start. Is this correct for your application? I saw a number of discussions mentioning a triple-start thread. I couldn't determine if that only referred to the cap and not the nib. The pen making subject is all new to me. 'Just want to make sure I'm making the correct type.