HSS or Carbide?
HSS or Carbide?
OK, so I got myself a set of those indexable carbide bits. They look great, but they don't seem to cut lucite well. Is it just me? A buddy of mine told me that HSS is better because you can get them sharper. The bits seemed OK with vulcanite.
There are hundreds of different kinds of carbide inserts. Some are good for some things, not so good for others. For Lucite, you need positive rake. You also have to hold them in a QC toolpost, insert tools are designed to have the toolholder radial to the work, not canted like with a lantern-style toolpost. An uncoated insert is usually good, too -- a titanium nitride coating, for instance, gives an insert increased wear resistance for cutting stuff like stainless steel or titanium, but decreases the tool's keenness a little, making it worse for soft stuff like acrylic.
When I have some time in the shop I'll try to get a number from the inserts I have, they're great for acrylic. They're not cheap, though, they're at least 10 bucks each, though they last forever. The holders are dear, maybe 70 bucks each.
Which may make HSS a better option for most folks, actually. You have to learn to grind them correctly, but they are cheap. Most machinists will tell you that HSS is a better choice for the home shop machinist, which pretty much describes a pipemaker. I *love* the insert tooling I have, but I was set up by somebody who knows a lot about different inserts and what they're good for. There was a very informative thread about this on the Yahoo South Bend group, I'll try to find it.
When I have some time in the shop I'll try to get a number from the inserts I have, they're great for acrylic. They're not cheap, though, they're at least 10 bucks each, though they last forever. The holders are dear, maybe 70 bucks each.
Which may make HSS a better option for most folks, actually. You have to learn to grind them correctly, but they are cheap. Most machinists will tell you that HSS is a better choice for the home shop machinist, which pretty much describes a pipemaker. I *love* the insert tooling I have, but I was set up by somebody who knows a lot about different inserts and what they're good for. There was a very informative thread about this on the Yahoo South Bend group, I'll try to find it.
Here's a pretty good discussion of carbide tooling on the South Bend Yahoo group:
http://groups.yahoo.com/group/southbend ... sage/40377
There are other threads, too, you can search the group for "carbide insert."
http://groups.yahoo.com/group/southbend ... sage/40377
There are other threads, too, you can search the group for "carbide insert."
Certainly looks good -- I guess that's a triangular insert, all mine are diamond-shaped. I always have to find some sort of key to puzzle out what the code means, it's pretty easy to get the wrong size. Carbide Depot is known for being helpful, though.
The topic of carbide inserts vs. HSS goes around on the machining boards fairly frequently. There are those who say that carbide is bad for home machining because our machines aren't powerful enough to take the heavy cuts that carbide likes, that inserts are designed for industrial applications where profit depends on max removal rates and minimum setup time. Then there are those who reply that there are plenty of inserts that do just fine with light cuts, give a great finish, and work great at low RPM. A frequent problem (not for you, Nick, I know you have a QC tool post) is that home shop machinists tend to buy a holder and inserts and stick it in a lantern style tool post, which presents the tool to the work at an angle and throws the geometry all off, usually making the tool rub rather than cut.
FWIW, I use both inserts and HSS. Being able to grind a special tool is handy. Being able to drop in a new insert when the finish starts to get ragged without changing anything else is handy, too.
The topic of carbide inserts vs. HSS goes around on the machining boards fairly frequently. There are those who say that carbide is bad for home machining because our machines aren't powerful enough to take the heavy cuts that carbide likes, that inserts are designed for industrial applications where profit depends on max removal rates and minimum setup time. Then there are those who reply that there are plenty of inserts that do just fine with light cuts, give a great finish, and work great at low RPM. A frequent problem (not for you, Nick, I know you have a QC tool post) is that home shop machinists tend to buy a holder and inserts and stick it in a lantern style tool post, which presents the tool to the work at an angle and throws the geometry all off, usually making the tool rub rather than cut.
FWIW, I use both inserts and HSS. Being able to grind a special tool is handy. Being able to drop in a new insert when the finish starts to get ragged without changing anything else is handy, too.
@Jack
I have a set of 1/2" turning tools that take the triangular inserts. I think this is the set I have: http://www.smithy.com/accessories.php?acid=20&aid=101 Up till now I have been using carbide inserts (TCMT). Do you think these HSS inserts will fit my holders: http://www.littlemachineshop.com/produc ... ch1=Search ?
I really suck at grinding HSS cutters, so these inserts might suffice.
I have a set of 1/2" turning tools that take the triangular inserts. I think this is the set I have: http://www.smithy.com/accessories.php?acid=20&aid=101 Up till now I have been using carbide inserts (TCMT). Do you think these HSS inserts will fit my holders: http://www.littlemachineshop.com/produc ... ch1=Search ?
I really suck at grinding HSS cutters, so these inserts might suffice.
Regards,
Frank.
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Grouch Happens!
People usually get the gods they deserve - Terry Pratchett
Frank.
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Grouch Happens!
People usually get the gods they deserve - Terry Pratchett
Could be -- these guys come highly recommended, though I haven't used their product. The bit about polishing to improve finish when cutting plastics caught my attention, though.Frank wrote:@Jack
I have a set of 1/2" turning tools that take the triangular inserts. I think this is the set I have: http://www.smithy.com/accessories.php?acid=20&aid=101 Up till now I have been using carbide inserts (TCMT). Do you think these HSS inserts will fit my holders: http://www.littlemachineshop.com/produc ... ch1=Search ?
I really suck at grinding HSS cutters, so these inserts might suffice.
http://www.arwarnerco.com./