Thread: Make a 5/8"tap

Mike
The Silver Steel would be my first choice.
It would need to be hardened & then tempered to a dark straw or light brown after your machining work.
I will be away for a while so will be out of contact for a short time.
Hope all goes well for you.
regards
Bruce

I'd be interested to know what they charge for shipping on an item like that.
Thanks

here we have a lesson

http://rick.sparber.org/gt.pdf

Originally Posted by BobL

I'd be interested to know what they charge for shipping on an item like that.
Thanks

Around ten bucks

You can buy one cheap enough.

Rdgtools HSS Acme Tap 5 8" x 8 TPI LH High Speed New | eBay


Don't know of the quality though.

Originally Posted by Clubman7

You can buy one cheap enough.

Rdgtools HSS Acme Tap 5 8" x 8 TPI LH High Speed New | eBay


Don't know of the quality though.

Yes I spotted that . I would rather make one and in the process learn how to do it ... that way I can make more taps later on when I need a odd size tap for a special job .

Mike

Hi,

Mintech in Brisbane has 5/8 ' silver steel for $26 for 300mm.Postage is likely to be a bit cheaper than from Chronos.

If it helps
Grahame

Hi Mike,
Something Phil suggested to me when i was musing about the Rivetts screws. Turn the new screw a few inches linger than required and also leave an inch or so of plain shaft. You can then cut the extra off and make it into the tap. The tap should then make a nut that matches the screw exactly.....if you turn the screw form dead on symmetrical. I have a pic somewhere of measuring with one wire for ACME threads...i'll try and find it.

Cheers,
Ew

Found it.....

Originally Posted by Ueee

Hi Mike,
Something Phil suggested to me when i was musing about the Rivetts screws. Turn the new screw a few inches linger than required and also leave an inch or so of plain shaft. You can then cut the extra off and make it into the tap. The tap should then make a nut that matches the screw exactly.....if you turn the screw form dead on symmetrical. I have a pic somewhere of measuring with one wire for ACME threads...i'll try and find it.

Cheers,
Ew

Found it.....

OK Ewan.. I understand . Thanks for the wire measuring info drawing . I plan on using silver steel for the tap . I will make the tap using the same tool and setup I will use for making the acme leadscrew itself , so in theory they should be a match .

The only thing I am unclear on, is what size minor diameter hole do I need to bore in the blank piece of bronze for the 5/8 ACME tap ? Do I need 2-3 thou of clearance for the minor diameter of the leadscrew ? Mike

More than that. The black book suggests 10 thou top and bottom. That is, the valley is 10 thou deeper like you said, but the tap should be made 10 thou bigger than the major diameter to give relief on the top of the threads too. The only contact should be the walls of the thread.

-From memory-

I was going to make the rivetts screws from silver steel, they are only 7/16. One is LH and one is RH. You may also want to wrap the tap in stainless foil so there is no oxidizing when hardening.

Ew

Hi

Been grinding the #8 ACME threading tool... it is going OK, but I need to measure the tip width . The book says it should be .041" wide .

I don't have one of those ACME thread gauges and I don't want to pay a exhorbitant price and wait 10 days for one from O/S .

Is there an easy way to measure the tip width ?

Mike

Have a look here -

https://www.woodworkforums.com/f65/yo...ml#post1488715

Phil solved that issue

Michael

Originally Posted by Michael G

Have a look here -

https://www.woodworkforums.com/f65/yo...ml#post1488715

Phil solved that issue

Michael

I forgot about Phils fancy gizmo.......... neat idea . Problem is it will take me a week to make one Mike