You need to turn at higher RPF when using carbide inserts and you need to take a more aggressive cut for the carbide to do its job as intended. That being said, many mini-lathes use carbide to good advantage if you pick the right insert with a smaller radius
and with the profile for cutting aluminum (works great with steel on small lathes)?
toggle quoted message
Show quoted text
?I have found for years that Carbide inserts are "dull' compared to properly sharpened HSS. My old shop teacher from 50 years ago used to show how a newly hones HSS bit would shave a sliver from your finger nail. Carbide Inserts
would just slide over it. He also like HSS because of being sharper, it would require less power to turn and cut, and it gave a better finish. He used to say that Carbide was for bigger, more powerful production machines. That being said. I have found that
when I used Carbide it works better for me if take the time to hone it on a couple of diamond hones/diamond flat plates working my way up to fine grit.
?Jeff
On Monday, August 7, 2023 at 12:28:14 PM EDT, pat goodyear <pgoodyear@...> wrote:
When I first got into lathes, ie. first Unimat.? ?I purchased a set of "Carbide" tools in 1/4" shanks from Harbor Freight, actually two sets one short shank and one longer shank.? I also purchased a set of carbide insert tooling, the indexed carbide tips
and I broke a few due to my lack of knowledge and skill.? ?I consulted with a machinist at work on my issues, he was a former tool and die maker, and he showed me the correct way to position and sharpen carbide and HSS tooling and allowed me to use their tool
sharpener to reshape the shanks on my cheapo tooling.? ?They perform very well now although I have since purchased a set or NOS Unimat bits for my Unimat, however I use the HF tooling on my 7X14 metalworker.? ?I have purchased and broke a few MICRO 100 boring
bars from EBay.? ?Since I purchased my QCTP which has a boring bar holder I haven't broke a single bar.??
pat
