selecting lathe HSS toolbits

I tend to use mostly HSS toolbits in my shop because the work well for me. At NAMES I saw a guy selling insert tooling using T15 toolsteel which kind of peaked my interest and got me to wondering about the advantages of various toolsteels.

What are the advantages of these various toolbit when used in a lathe: Import M2, RexAAA, MoMax, MoMax Cobalt, Tantung

My current opinion is:

- Import M2: Use on Mild steel or aluminum. Don't expect to last too long on anything tough. I have LOTs of these and don't seem to use them much after trying MoMax

-Import Cobalt: very little experience. Not too motivated to try them after using other toolbits.

-RexAAA: No experience. I bought a box at Cabin fever and I have not tried them out yet. A web search says they are T4 containing lots of tungsten and Cobalt so I expect them to work well. Will they work as well as MoMax?? Too bad I only got 1/4 inch

-MoMax: Better than import M2. Longer life

-MoMax Cobalt: use on tougher steels like 4140 They seem to work well on other things too. Pretty tough to grind and expensive too.

-Tantung: Fast turning of tough steel. 2-4 times M2 speed. Does not like slow speeds (cutting edge chips) Recommend cutting speeds of 100-300. Pretty tough to grind and damn expensive. chuck

Reply to
Charles A. Sherwood
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Gee, endless amout of OT in this news group and I cant get ONE comment on a metalworking topic?

In article , Charles A. Sherwood wrote: :I tend to use mostly HSS toolbits in my shop because the work well for me. :At NAMES I saw a guy selling insert tooling using T15 toolsteel which :kind of peaked my interest and got me to wondering about the advantages of :various toolsteels. : :What are the advantages of these various toolbit when used in a lathe: :Import M2, RexAAA, MoMax, MoMax Cobalt, Tantung : :My current opinion is: :- Import M2: Use on Mild steel or aluminum. : Don't expect to last too long on anything tough. : I have LOTs of these and don't seem to use them much : after trying MoMax : :-Import Cobalt: : very little experience. Not too motivated to try them : after using other toolbits. : :-RexAAA: No experience. I bought a box at Cabin fever and I have : not tried them out yet. A web search says they are T4 containing : lots of tungsten and Cobalt so I expect them to work well. : Will they work as well as MoMax?? Too bad I only got 1/4 inch : :-MoMax: Better than import M2. Longer life : :-MoMax Cobalt: use on tougher steels like 4140 : They seem to work well on other things too. : Pretty tough to grind and expensive too. : :-Tantung: Fast turning of tough steel. 2-4 times M2 speed. : Does not like slow speeds (cutting edge chips) : Recommend cutting speeds of 100-300. : Pretty tough to grind and damn expensive.

Reply to
Charles A. Sherwood

A long time ago I got some insert tooling from Wholesale tool that use T15 inserts, a boring bar, a fly cutter, and a lathe tool. They work very well.

I can't comment on the other tool steels. I use them, but don't do enough of any one thing to make good judgements. That is they all seem close to the same to me.

Dan

Reply to
Dan Caster

The HSS inserts are for guys that are used to swapping carbide inserts and maybe don't know how or don't want to take the time to grind bits.

Import tool steel is all over the map. Had one batch of Indian 10% cobalt that was as good as anything I'd ever used. Next batch dubbed over turning aluminum. No more import stuff for this guy. Might be of some use as fishing sinkers or drapery weights.

I've used Rex AAA, a bunch of it came with some stuff my dad picked up one time, I used it for years for general purpose turning on all sorts of steel and aluminum.

Never used MoMax

I've used Tantung G on some really nasty high-carbide cast iron. Stuff that would take the edge off carbide and HSS tools. With Tantung G, it would just slow the lathe down and keep cutting. Instead of the dark gray powder you usally get off cast iron, this swarf had little silver bits in it. After I was done turning, the bit looked a little dull, about 30 seconds on a diamond hone fixed it right up. Tantung G isn't HSS, there's no iron in it. On a belt grinder, it forms up about as fast as any HSS bit, I was a bit surprised at that. Worth the bucks. Makes good internal threading tools, too, where you don't want to have to pull the bit out for sharpening and then have to pick up the cut again. If it costs 3-4 times as much, but you get 10-20 times the life out of the bit, you're ahead of the game. I never had any trouble with edges chipping on lathe bits made of it, even with really severe pounding on interrupted cuts. Makes me wonder if there isn't a lot of batch to batch variation if you're having that problem.

Stan

Reply to
Stan Schaefer

Good to know!

I never though of using tantung on CI. This is one of the few times I use brazed carbide toolbits instead of HSS. I will have to try Tangtung next time I need to turn a flywheel. Thanks for the tip.

I initially ground my Tantung toolbits with the same angles as HSS. I'm not sure, but I think it should be ground with angles closer to carbide??

Reply to
Charles A. Sherwood

I was taking a very heavy cut at very low RPM. Learned not to do that.

Reply to
Charles A. Sherwood

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