Lathe inserts

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Sep 13, 2018
Hi again , now that ive started fiddling around with my new Sieg 550w Lathe , i am truly bewildered by the amount of different types of inserts available . i have looked on the net and am not much wiser ! regards what to select. I believe CNMG ? are the most popular or is it CCMT for small machines , i will be only attempting very basic Lathe work at first , mainly in Aluminium to start with , i already have a QCTP and some boring bars , Live Center and Drill Chuck , just need advice on a few standard issue Holders for facing andside cutting/sleeving , cheers.


H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Feb 24, 2018
The CNMG are great inserts, but the tools usually have at least a 3/4” (19mm) shank and need some oomph to propel them, the CCMT tooling is available from 1/4” (6.4 mm) or 5/16” (8 mm) and up, have small inserts CCMT 21.51, the tool also excepts CCGT insert, some made especially for aluminum. If you want to go carbide, I’d start with the CCMT inserts and tooling.
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Active User
H-M Platinum Supporter ($50)
Dec 20, 2012
I think you're referring to a mini-lathe, about 7"? If so, then that's a small, slower, less rigid lathe that would do better with HSS tooling. On the other hand, if you want to go with inserts then consider a set of AR Warner tools that take HSS inserts or if you're dead set on carbide then look for an SCLCR (RH) or SCLCL (LH) tool holder that takes CCMT and/or CCGT inserts (same tool holder takes both types of inserts).

On a little lathe like yours, I suggest a 3/8"/10mm tool size. A set can be had for cheap on ebay or Amazon, like this one: https://www.amazon.com.au/Hibroo-Turning-Carbide-MGEHR1010-SER1010H11/dp/B07D6PVR49/ref=sr_1_4?ie=UTF8&qid=1538856285&sr=8-4&keywords=sclcr+tool+holder

The SCLCR tools allow you to turn and face with one tool and without moving the tool for either operation.

The CCMT inserts will serve for most materials while the CCGT inserts are usually uncoated and ground to be very sharp for use on Aluminum/aluminium. Since your lathe is small, it cannot take huge cuts so when looking for inserts, get the smallest nose radius you can find. For example, a CCMT 25.20 or 25.21 insert.


John York
H-M Supporter - Gold Member ($25)
Jun 7, 2013
I'd recommend TPG inserts in perhaps 1/4" I.C. size, being positive rake, they consume less power and cut more freely than other types.
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