Money to spend on inserts and holder for lathe

Steamchick · May 23, 2022

I have never had a problem with round tool bits in round holes. Some have flats ground on to align with the clamping screws, but not all. (Really small tools - <1/4" dia - are just round, in drilled holes).
Just be sure to keep you round HSS stock separate from your S/S, Silver-steel, or BDMS!
K2

Bentwings · May 24, 2022

wazrus said:
Like many, i have a collection of boring bars, for both chuck work and between centres. The between centres type shown in other contributors' has the cutter bar hole directly across the diameter. Most bars I've made have had their tool holes at an angle across the bar axis, largely to allow an outside micrometer to take a reading. Very much more convenient to adjust the cut than when the tool is projecting - even a small amount - on the other side. i don't see a need, either, to cut a square hole, but round as Mike Ginn suggests. The hole angle doesn't really matter, but a possible 'benefit' might be that the bar could be stiffer., especially with a smaller bar. If boring from the saddle, I very much prefer to lock the cross-slide in one position for the entire process and not use the lathe screws to adjust the cut.

if you make your broach or similar out of A2 tool steel it’s much easier to heat treat and draw so you can make very accurate tools .

Iampappabear · May 24, 2022

Look for Sandvik Coromant, just about the best there is. You will find triangle inserts the best option, try to avoid tips with holes in to lock them just makes them more prone to cracking and a top clamp works fine.

Colin

ajoeiam · May 25, 2022

Iampappabear said:
Look for Sandvik Coromant, just about the best there is. You will find triangle inserts the best option, try to avoid tips with holes in to lock them just makes them more prone to cracking and a top clamp works fine.

Sorry - - - your comments above are quite a bit like " Ford makes the only car worth buying, there is nothing that drives better than my Lincoln."

If you are starting from scratch (first purchases of holders as well as tooling) there are a plethora of high quality companies.
Sandvik Coromant is a great company but looking at a few other options might also be useful.
Names like Iscar, Kennametal, Ceratizit (and there are more!!) come to mind - - - then for specialty stuff there are a lot of smaller manufacturers.
Was looking for a supplier for tooling for a poly-V (multi-V - - - - check your automotive belts today) and was surprised at how few options there were (and Sandvik wasn't one of them.

Even just using triangle inserts - - - - wow - - - even if all you're doing is finishing there are other options.
Triangle inserts may be a very 'safe' choice but I'm not sure I would even want to think that they're the 'best' option.

If you're finding that triangle inserts are your 'best' option - - - because your equipment is very prone to vibration, is severely under powered, and you've never tried grinding your own tooling (HSS and brazed on carbide) - - - well - - - - please consider looking into other options than cemented carbide. There is a huge range of possibilities out there. You might find that you don't even need cemented carbide and the flexibility - - - - well it will astound you.