Boring bar or threading tool?

[Alan Fisher 1Participant @alanfisher1]

Hi all, totally new to this metal turning lark.

I have been turning wood for 10yrs on an Axminster M905 lathe

Now that I have aquired my Grayson 3.5×20 lathe, christmas is rapidly approaching and I need some tooling.

I have been looking at boring bars and threading tools, and was wondering if a 12mm diameter threading bar with a triangular shaped insert in an 11mm size, could be fitted with a TCMT11 insert ad used as a boring bar?

Or are they both different animals completely?

[Alan Fisher 1Participant @alanfisher1]

[jonathan heppelParticipant @jonathanheppel43280]

"Fraid so. If you want a two-in-one, you'll need to do it the old fashioned way with HSS bits, and save yourself a packet too.

[Russell EberhardtParticipant @russelleberhardt48058]

Now that you have your lathe why not make a set of these and some split rectangular holders. You can the grind short HSS bits to suit whatever job you need to do.

Russell.

[Ian S CParticipant @iansc]

With the boring bars that Russell shows, you do not even have to make the holes for the tool square, you can do as I do for some of mine, and use things like broken centre drills, old taps, or worn out end mills, waist not, want not. Ian S C

[BazyleParticipant @bazyle]

And if you make your first bar from square stock turned down it fits the normal toolpost though you are then stuck with a fixed length. So you can make the second one from round and make the holder block using your first bar.

[Sub MandrelParticipant @submandrel]

But if you DO want your dual purpose bar, choose one with a round shank, then you can tip it up to present the insert at a suitable angle for boring. You will also need to adjust the height.

Neil

[nigel jones 5Participant @nigeljones5]

If your that new to metal I would master the boring first – mine gets used a lot.

[Alan Fisher 1Participant @alanfisher1]

Thanks for the replies lads, all duly noted.

Those bars look nice Russell

Looks like I still have a lot to learn.

[capnahabParticipant @capnahab]

Russell, those boring bars look so good. Did you make them ?. I have an Aloris one which I will post a picture of.

If you made them I would like to know how you got the round hole so nicely done.

[capnahabParticipant @capnahab]

the aloris version.

[Russell EberhardtParticipant @russelleberhardt48058]

No, I didn't make them. That was just a random picture to show the principle. Here are a few I have made:

The one at the front is for small holes. The next one has the hole for the toolbit at 90° for internal threading. The one in the homemade holder is for general use and the between centres version at the back has the hole at 40° to the axis and a 40 tpi screw behind the bit so that each turn of the screw increases the cutting radius by 16 thou.

Drilling the hole at an angle is no problem.  I set the bar up at the required angle in it's holder, made a flat with a slot drill in the chuck and then replaced the slot drill with centre drill followed by a just undersized drill.  Finish off with a reamer in the chuck if you have one, if not use the final size drill.

Russell.

Edited By Russell Eberhardt on 16/11/2013 11:21:21

[Ian S CParticipant @iansc]

When making this type of boring bar, it's worth making it double ended, one end with the hole at right angles, and the other end at about 45*, you don't need to have a tool in each end all the time, but it is one less lump of metal taking up room in the lathe tool draw. Ian S C

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