What's new
What's new

Need schooling on inserts

hydrolastic

Plastic
Joined
Oct 14, 2009
Location
WA
Specifically ccmt 21.50.5 years ago i upgraded lathe tools and boring bars to all the same size insert ten plus years later i need to order more. I seem to remember there were two radius sizes but i dont know what to order and what the finish is. For instance i had two radius inserts i used this one is a mitsubishi 060202 i think it is the sharp one with a .002 radius but i did not save the package for the larger radius ones i had also. i am on my last screw and the wrench needs replacing. As i remember the bars were iscar. I looked in the MSC catalog and was lost as to what i was looking at also the grade i used to buy i think was 5 (yellow)but i now see that there are thousands of inserts with wildly varying prices i used to pay 60 dolars for a package of ten i would think they would have gone up but i was seeing some inserts in the 20 dollar apiece range. i know weird questions but i dont need to replace these that often. Aaron
 
When you find out what you have, ..........look here and see if Curtis (Exkenna) does what you want LATHE INSERTS

No affiliation, but I know he has a very good rep on this board, and if I lived in the US I would buy from him.
 
Take your calipers or mic and measure the length across cutting radius tips on your unknown and I can tell you the radius size.
A bit tricky to get a accurate measurement across the corners on a positive tool but rads come in distinct jumps. The smallest available rad is usually a .005 to .007 and the allowed tolerance on a "M" sort of swamps this.
Using a mic you anchor the bottom rad on the fixed and sort of make little circles with the top gradually bring on the thimble to find the high number. It's a touchy-feely task and not recommenced on new inserts as it is very easy to chip the tip doing it.

A sharp corner 21.5x measures .389. the amount under this number tells you the radius size.
2 X (.5557 X Rad)....(perhaps a drawing would explain it better)...

The same insert will have two numbers. A 06 is a 2. Metric and imperial callouts for the same tool.
They are made in inches. In this case a 1/4 inch IC, 3/32 thick.
The ISO metric standard came later so it is a approximation of dimensions.
Screw should be a M2.5 with a standard torx head but a funny angle. (Bottom though hole size should be .110, top opening should be .146)
Likely a T-7 although there are variations.

It is all very confusing. :willy_nilly:......Then we get into grades. :wall:
Bob
 
When you find out what you have, ..........look here and see if Curtis (Exkenna) does what you want LATHE INSERTS

No affiliation, but I know he has a very good rep on this board, and if I lived in the US I would buy from him.

Curtis is the most helpful insert sales guy ever, I bought from him again on Thursday. Good stuff good prices good customer service, What more could you want? Got a question? Call him or e mail and he will call you. Beats the crap out of msc and their clueless phone order people
 
On the box of inserts there usually is a ANSI Designation (Inch) and ISO designation (Metric), here is a quick breakdown of each to help you narrow down what you need:
.008" Corner Radius: CCMT21.50.5 (ANSI) & CCMT060202 (ISO)
.015" Corner Radius: CCMT21.51 (ANSI) & CCMT060204 (ISO)
.031" Corner Radius: CCMT21.52 (ANSI) & CCMT060208 (ISO)

The inserts above are Molded which is the letter M in the CCMT designation, if you need a smaller corner radius then you will need a ground insert which is a CCGT designation. Here is a breakdown on them:
.002" Corner Radius: CCGT21.50.1 (ANSI) & CCGT0602005 (ISO)
.004" Corner Radius: CCGT21.50.2 (ANSI) & CCGT060201 (ISO)

As long as your enter in the correct radius designation above you should find the inserts you need Aaron! For CCMT21.5_ Inserts the most common corner rads out there are .008" and .015". I really like the Korloy HMP Chipbreaker in the PC5300 grade for these inserts, the HMP Chipbreaker has a DOC Range of .020"-.118" per side and the PC5300 grade is a great general purpose grade that can be run in all materials and hold up well. Here is a link to them:
Korloy CCMT21.5_ HMP PC5300 Inserts

Hopefully this helps you out Aaron!

Mike
 








 
Back
Top