Lathe toolbit composition

[dberndt]

I'm looking to order more HSS toolbits for my lathe. The ones I have used until now either came from the previous owner of my lathe or my instructor.

I'm looking on kbc tools and I see they have either M-2, 5% cobalt or 10% cobalt. Can anyone explain the merits of adding more coblat to the mix? Which one do I want for general turning.

Also how do you guys cut your HSS bits. I am going to need to shorten some of these to fit into a boring bar I use to cut internal threads. Abrasive saw?

[Tin Falcon]

DB :The addition of cobalt increases red hardness. Or increases the temperature at wich the tool is still usefull. It also extends tool life between sharpening. The higher cobalt alloys are for tougher alloys such as stainless steel. IMHO If you are cutting mosly brass an aluminum M-2 is probly fine. The higher cobalts also grind slower.
As far as cutting bits I have used the dremel tool with an abrasive disk.

Tin

[HWooldridge]

Ditto on notching with a Dremel cut-off disk and then breaking off the piece.

I must be an anachronist since I use nothing but a lantern post and HSS bits for my lathe...:-)

[Evan]

I must be an anachronist since I use nothing but a lantern post and HSS bits for my lathe...

Count me as one as well since I do 99% of my lathe work the same. I do sometimes use a small diamond insert to turn off hard anodizing though.

[Mcgyver]

to break them, I just make a notch around the the periphery with the edge of a the benchgrinder wheel, put it in the vice, don safety goggles and give it a light smack, the again the standard size i use 1/4. some guys like the 1/2, but there's not a benefit as far as I'm concerned, just don't have crazy amounts of overhang.

don't mean to steal the thread but this is a relevant question - do you guys think that for a given grade hss is hss for example is hss from india is crappy as their other stuff or would you notice a difference between the cheapest and some brand name bits?

99% hss, but haven't touched the (gag gag) lantern in years :D

[CCWKen]

When I got the Craftsman lathe, there were some old (new) HSS bits in the box. They are marked from Japan. I've used ONE on a bunch of W-1 drill rod. Haven't had to resharpen it yet--Just a touch with a stone. It sure keeps a better edge than the China HSS bits. They may have cobalt but it's not labeled so.

I've been ordering all 10% cobalt, C2 and C5 bits. When all the HSS are used up, that's it for plain HSS for me. It's ok for aluminum and brass but they don't hold up on anything else.

[CCWKen]

By the way, I put the old Craftsman back to work. I'm impressed. Chip control is my biggest problem with it. :D

[A.K. Boomer]

whats lantern mean?

[gmatov]

I don't mean to make this commercial, but does anybody need some HSS bits, from 1/4 X 1/4 to 3/4 X 3/4, hell, 1/2 X 1, even, as well as cut off blades?

I'm cleaning out the shop of stuff I'll not use anymore. That or the dumpster someday, after I am gone.

Cheers,

George

[CCWKen]

whats lantern mean?

I'm not sure which lantern Mcgyver is "grabbing"... :D but in this context, it's the lantern style tool holder. Seen here:

http://i21.ebayimg.com/04/i/06/ac/81/6b_1_b.JPG

[Evan]

I like the lantern style holder because it's so easy to adjust center height. I dislike it because you have to do it every time you change tools. I have a quick change too with several holders. I use it mostly when I need to do some turning and I have the milling table mounted. I just bolt it to the the milling table wherever is convenient.

[A.K. Boomer]

I'm not sure which lantern Mcgyver is "grabbing"... :D but in this context, it's the lantern style tool holder. Seen here:

http://i21.ebayimg.com/04/i/06/ac/81/6b_1_b.JPG


well i can see why they call it that --- thanks ccwken

[Forrest Addy]

I'd suggest the M-2 as well for most work. Few home shop machinists push the limits of stock removal so unless you do a lit of work in staimless and tough alloy steels. Only then would I suggest M-42 (the 10% cobalt) because its more expensive.

What country of origin is another matter. US, European and Isreali made HS tool steels are still the best in terms of overall consistant performance and edge longevity. They're closely followed by Japanese and Korean steels when equivalents are applicable. My experience in third world brands of HS tool steel is so sparse as to be anecdotal so don't quote me ans an authoritative source. That said, the few samples of Indian and Indonesian HSS I've tried don't hold up as well as their US counterparts.

To be fair, and to gain reliable results, trials of tool steel should be done in a blind lab test setting where samples receive random numbers and are tested in a battery of applications. It's a big expensive deal to conduct such tests. I've been out of the trade journal loop for some time so I don't know what's hot and what's not. I probaly have a lifetime supply on hand of major HSS tool steel from 1/8 in graduated sizes to 3/4 plus larger rectangles.

If you buy HS tool steel bits by the box it's cheaper than by the stick. Also you can grind your favorite tool configs and still have a few left over for special tools. This way you won't be wastefully re-grinding a few tools to suit the dozen traditional shapes you need for your lathe applications plus the many specials. It's not uncommon for a home shop lathe operator of some experience to have 20 active HS tools in his collection plus boring bars.

There's been generations of manufacturing done with lantern tool posts so don't sneer at them. They work well for general use. They're just not as stiff and handy as a quick change. I have the strongest and handiest quick charge tool post system there is but I still use a lantern style when the needs comes up.

[dberndt]

Who sells toolbits by the box or as long sticks? I thought i saw them on msc the other day but now they elude me.

[JPR]

I agree with the cheaper hss not holding an edge.

I bought 10 pieces of cheap hss 1/4 x 1/4 and 1/2 x 1/2 last year for one off stuff and to knock down welds. I have tried to rough cr a couple of times with them and they easily nick and lose their edge quickly.

[Millman]

Ahh, just drop those off at the shop too, I don't have much planned today anyway. How close tolerance do you want on those.....000037 close enough? I'll have them done by Christmas.....2008.

[SGW]

I use Cleveland Mo-Max Cobalt HSS toolbits, in a lantern toolpost. I've also got some M2 toolbits, and they work okay too.

[Wirecutter]

I inherited some stellite, which I use on tool steel and stainless in my lathe, and I love it. I gulped hard when I actually purchased some, though. Stellite is 39% cobalt, 30% Cr, and 23% Ni, and it has great red-hardness. It's mucho expensive, though. I have a couple of cobalt-containing cutter materials, and they seem to hold a pretty nice edge without the brittleness of tungsten-carbide.
What I like most about HSS is that it's cheap and cuts a lot of materials just fine.

Anybody know anything about some stuff called L605? It's 53% Co, 20% Cr, and 15% W. Is it a cutter material?

-Mark

[Evan]

I'll let you guys know what I find. I have always used Dormer HSS bits. Recently I ordered a handfull of Chinese HSS stock to give it a try. I haven't yet ground up a tool from it. Maybe I'll do a comparative test on a steel bar this weekend. I have some chrome moly 2" scrap round stock that will show up any weaknesses.

[tdmidget]

I'm with Boomer here- Why can't we call things by their proper name. That's a ring and rocker tool post.
tdmidget

[CCWKen]

No one is arguing about the name. It's known by both terms. I've even heard it called POS tool holder. :D I was simply answering a question. The lantern style defines a type of rocker tool post. There are other rocker tool post designs.

[J. Randall]

George, I could use an assortment, I have been getting by with a little dab of import stuff. I use mostly HSS, as it's just hobby stuff with me. Contact me by email with your terms. Thanks James

[gmatov]

James,

I can't talk to you by e-mail. I checked.

I don't know what they are worth, haven't bought a bit in 30 years. Looking on line, anywhere from a buck to 5 or more per, depending on size. I run up to 3/4 square X 5 inches long, from 1/8 and everything in between.

Only have 60 unground, new (well, 20 years or so old, but unground), have 150 or more ground tools, many forms, which I use some of, Whitworth thread tools, 'O' ring tools, number of "Carballoy" brazed tip tools, don't use them, rather use HSS or inserts. Inserts, I have way too many of, also.

Man, I got way too much stuff. Couple dozen 3/8-24 taps. Bunches of EZ Outs. Knurls. Heli-Coil taps, mostly 3/8-16.

Don't know what to do with it all. I am NOT an e-bayer. Bidders there go crazy. I don't want to sell to them.

Cheers,

George