Boring bar or threading tool?

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 3.5x20 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?

"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.

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.

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

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.

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

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

Thanks for the replies lads, all duly noted.

Those bars look nice Russell

Looks like I still have a lot to learn.

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.

the aloris version.

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

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