I have lots of HSS tooling that came with the Myford. But most of my toolholders are loaded with insert tooling. On odd occasion i will use HSS but rarely.

Steve.

I still use a couple of old carbon steel tools. can't beat them for finish on free cutting materials.

Roy

There is a big advantage using carbide inserts in industry. The carbide can withstand higher temps generated with bigger cuts so that if there is sufficient horsepower, deeper cuts and higher feeds cuts down on the time from raw stock to finished product. The carbide is harder so it lasts longer and the inserts can just be changed out without having to stop and sharpen and since they are a standard size the tool doesn't have to be readjusted, just pop in a new insert and you are ready to go. However, being a harder and more brittle material than HSS, they cannot be as sharp or the edge will break off too easily. No problem with enough power but on a lightweight, under powered machine the sharp edge is needed. Carbide inserts can be sharpened to make them cut more like HSS but then much of their advantage is lost as sharpening them takes more time than HSS. With all that in mind, I use a combination of HSS tools and carbide inserts. I have trouble seeing the fine details so a treading insert will get me better threads than a tool that I sharpen. Boring bars with carbide inserts seem to be better for my purposes as I can get them in small enough sizes to use in my small lathe.

Hi Brian,

I use both carbide tipped tools and HSS tools. Using carbide tipped tools on a small lathe has not given me any problems, you can get carbide inserts that are ground and polished. They are intended for non-ferrous metals but in my experience they work well also on mild steel. Carbide tipped tools work even if you are taking light cuts at lower speeds than industry uses. If machining castings (or other materials with hard spots) I use carbide for the first cuts and HSS for finishing

Thor

I have a Super 7 and all the tools in QC toolholders are carbide except for one tangential tool and a home-ground 60* threading tool. No problems. An existence proof that carbide works fine in a Myford.

There are new grades of carbide coming out all the time. The latest ones are very sharp and are extremely good for finishing and you don't need high surface speed or high RPM to get a good finish. I don't use the high speed range on my S7. I have a TNMG holder, the only negative holder I use. But use the positive inserts for that holder. Ones for steel and ones for aluminium. Lately I have been using what is sold as a wonder insert out here. See .my album. They work very well. There is a new range of ground coated inserts that are very sharp and are excellent for roughing out as well. When they dull from finishing become roughing inserts. The CCGT09 and the CCGT06 inserts I use in my boring bars and external turning tools. The DCMT11 is only for the outer turning. Here in NZ quite a few of the tool companies will sell one or 2 inserts to the home hobbyist. I only use HSS for form tools that are for a specific project.

Vic

Get yourself some "Stellite" to use in your tangential toolholder, it lasts much longer before it needs sharpening again.
I use it all the time and occasionally give it a lick over with one of those plastic handled diamond files to keep it keen.

Phil

I second the CCGT style of carbide insert for use on lower powered lathes.

Designed for use on Aluminium they are good for steel to.

The rake is a bit much for Brass but the sharpness is ok for small diameter work.

Steve

Edited By The Novice Engineer on 19/08/2021 23:03:58

Slightly off topic, but, while searching for a solution to a poor finish on my Super 7 I sharpened the HSS tool, tightened the toolpost, locked all non moving parts. Still poor so put on tipped tool. Still poor finish even on lightest cut.

The only way to go was look at the headstock and yes there was movement. 10 mins of C spanner time and the cut finish is now perfect.
How often do people check the headstock ?

I obtained a couple of these non-ferrous inserts a while back and was initially pleased, but then had an iffy finish on a couple of jobs in Aluminium. On close inspection, i could make out a tiny peak of alloy built up on the cutting tip which was quite a job to chip off. Once cleaned, worked fine until the next time it happened again some time after.

I can't say what grade alloy was in use as I just have a general stock that was bought at shows etc, generally was cutting at high speed, so a bit bemused at the cause of the problem. Any ideas on the reason behind this anyone? Think I purchased them from a normal on line tool dealer I use regularly.and don't remember them being cheap & cheerful!

regards. Mike

Don't agree …. are you sure you correctly translated from the Spanish?

Edited By Peter Greene on 19/12/2021 19:17:44

Happens to all types of cutter. The insert is innocent!

Aluminium is prone to weld itself to the cutting edge because it's relatively soft and has a low-melting point (660°C). Once the cutting edge is covered by a thin layer of Aluminium, it's blunt, so much more heat is generated as the Aluminium is scooped off making it even more likely to stick. Once started, quickly gets much worse.

Easy answer is some light-oil lubricant – paraffin, WD-40, or thread-cutting fluid. Sharp uncoated cutters help too. Also, being aware it happens.

Usually Aluminium can be scraped off the cutter with no bother. If it's stuck hard, leave the cutter immersed in some Caustic Soda or Washing Soda solution, and the Aluminium will dissolve slowly. Caustic Soda is quick but a bit nasty to handle, Washing Soda is safer but takes longer.

Dave