H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
- Nov 24, 2013
Very informative post, thanks Sami.The radius at the cutting edge is denoted by the last two numbers of your insert identification number. For instance one of the indexible tools I use on my mini lathe uses CCMT 060204 inserts. The 04 means that the cutting tool has a 0.4mm radius. You could try and source a smaller radius insert however in this instance the CCMT 060204's are probably the most widely available.
A larger radius will generally give a better surface finish but you are right in saying that it will require a greater cutting force. Personally I have never found carbide inserts to be a problem on the mini lathe although I have never really used a lot of HSS tooling. I do most of my turning in stainless steel which I found blunted HSS tooling too quickly and I was forever sharpening them. This may well be due to poor tool geometry, poor grinding, improper feeds and speeds or any combination of the three! For me the convenience of being able to switch out the cutting tip when it is worn led me to stick with carbide.
Those look to be ISO inserts, I suspect TCMT's. The ISO designation system allows you to work out what insert you have based on the shape, clearance angles and insert type. It sounds confusing but it's really quite simple. Have a look at the PDF here - there's a handy identification guide on page 6: https://www.slideshare.net/mx100/dijet-draaibeitelscnmgMy set as shown in my post #1 came in a case and there is no info on the inserts except in the case it’s marked “5pc Index Carbide Turning Tool Holder Set 1/4” #M0136”. I got it thru eBay from a vendor in UK and perhaps it’s a cheap set but for a hobby user like me I would suspect its ok.
So you turn SS with your mini lathe and I’m glad to hear that because I never thought a mini can handle SS however I assume with the proper tool and feed rates / RPM any material will be fine.