Thread: Boring bar threading?

As a complete beginner when it comes to insert tooling I have what I think will be a silly question! I have a very nice little boring bar and I wonder if I can use a 60deg threading insert mounted on the bar for external thread cutting? My chuck is held on by studs and I would like to try threading in reverse away from the head stock like I know several members here have done. I have attached some pics on the boring bar I have - is there a way to use it as a threading tool as well or is it only to be used for internal boring?

etched on the tool are the following - SR34-514 WX**0403 A10K-SWLXR04-D120

if I can’t use this one is there a preferred threading insert holder and inserts anyone can recommend?


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Hi there,

I have a couple of threading insert holders (inside & external threading) and both 55 and 60 degree indexed threading inserts.

I got them from eBay for probably $20 each. They work pretty good. I now only use hss for threading to a tight shoulder etc.

Im not sure if the threading inserts will fit that boring bar but for the price of 1 boring and couple of inserts, just buy one!

Simon

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Originally Posted by Danger Mouse

As a complete beginner when it comes to insert tooling I have what I think will be a silly question! I have a very nice little boring bar and I wonder if I can use a 60deg threading insert mounted on the bar for external thread cutting?

Short answer: No.

The main reason being that your boring bar does not take actually triangular inserts (which is the shape of threading inserts), but what's called a Trigon shape; which has an included angle of 80 degrees, not 60. Triangular inserts will not seat properly.

I think the tool holder you need for reverse external threading of RH threads is a SEL tool holder, and IR inserts, eg SEL1212H16 and 16IR AG60 inserts.
The 16IR will cut metric 0.5-3.0mm pitches.

Steve

Thank you everyone - that has really cleared it up for me. I’ll go and see what I can grab on eBay.

Ian

I like your thinking.
I know i try and i wish you could use 1 tool for every thing.
imagine that. Use your toaster to paint your walls,jump start your car as well as shave...

Hi Ian, Guys,

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This is the shape of the boring bar and insert. You can get very close to the work with these. That tip point is about a MM away from the flat surface. I'm about to cut the thread for the elephants foot for a dial gauge.

Thanks Baron
Looks exactly like what I am after. Does this use the inserts Steve mention in his post above?

Ian

Hi Ian,

Yes it does ! I have both 55 and 60 degree inserts for mine. It came from "Banggood" very cheap, about £6 or £7 UK post free, complete with 3 inserts.

I also bought a bar that holds the same inserts but is intended to go straight in like a normal lathe tool.