Need To Make A 6mm 1.25 Lh Tap

[buffdan]

I need a 6mm 1.25 LH tap, to make a nut for my DoAll bandsaw..
I cant find a commercial one, so I am trying to make my own tap.

I am using hardening tool steel, not sure what type I have though. (O1, W1, etc)
Cutting the threads on my lathe, the threads are rather rough.
I have tried new carbide form tool, and very sharp HSS.. Same deal.. Rough threads.

I know tool steel can be a bugger..

Any tips?

Thanks..

Dan

 

[cvairwerks]

Sure it's a M6x1.25, as that's not a standard pitch?

 

[T Bredehoft]

Anneal your blank, heat red hot, pack in ashes to keep it warm while it cools. Cut it like a screw, cut flutes in it, harden it, Heat it till it falls from a magnet (into light oil). At least hone the flutes to make sharp edges. Good luck.

 

[Holescreek]

Since the tap won't work until hardened it would pay you to know which steel you are using before you put a lot of work into it.

I'm curious about the size as well. I work in an industry where odd metric sizes are the norm and this one is new to me too. How sure are you on the size? Suppose it's a proprietary tap DoAll has made special?

 

[4GSR]

A DoAll band saw with Metric threads? How old is this saw?

You sure that is not 1/4-20 left hand?

 

[RJSakowski]

Why a left hand thread? If it is a matter of the nut loosening in use, you could use a jam nut to lock it or a castellated nut with cotter pin. Can you replace the stud another size like M8-1.25? It seems like a lot of work to go through for just one nut.

 

[buffdan]

It is 6MM 1.25 LH... for sure..
Its the shaft of the chip brush drive.
There are different ways I could go about this.. Like make new shaft for the geared chip brush drive, etc.. But I wanted to see if I could make the nut, hence my path of making a tap..

Thanks for the inputs guys.. maybe I need to re-think this..

Its a very odd-ball thread..

I forgot to mention that its a DoAll 916 horizontal.. maybe from 80's?? Taiwan made
The saw cuts great..

 

[buffdan]

It is 6MM 1.25 LH... for sure..
Its the shaft of the chip brush drive.
There are different ways I could go about this.. Like make new shaft for the geared chip brush drive, etc.. But I wanted to see if I could make the nut, hence my path of making a tap..

Thanks for the inputs guys.. maybe I need to re-think this..

Its a very odd-ball thread..

I forgot to mention that its a DoAll 916 horizontal.. maybe from 80's?? Taiwan made
The saw cuts great..

Ha, I am such a dope....
I double checked..
Its 20 pitch.. And the OD is .239.. Loose 1/4 inch
Groan.....
I should have know better
Thanks Ken... You were correct !
Ok guys, you can laugh now..

Lesson learned by me.

Love this site..

 

[rrjohnso2000]

Nothing to feel too bad about. Learning to make a tap sounds like a fun project. Although I'm glad the resource section had better information.

 

[4GSR]

The reason I brought it up is, DoAll is "old school" and anything built before say 1980-1985 is more than likely going to be imperial especially if it's a American manufacture. I'm not saying this is the case every time but most of the time. Anything after that up to the early 1990's, especially Asian manufacture may have a mixture of Metric OD's with English pitches or a mixture of both Metric and Imperial stuff used. And of course today everything is composed of Metric components only except for lead screws.. Not always the rule but flexible guidelines that can be followed.