Well, I'll chime in here and see if I can be worthy of George's 10 on the tool geek scale (or get an F in the process).
There is a method to the madness of carbide inserts. There are industry standards and all the letters really do mean something.
Here's a link (so as not to incur any wrath):
http://www.carbidedepot.com/formulas-insert-d.htm
In decoding what our Polish brother has given us (DCGT) we get the following:
D= Diamond shape with a 55 degree nose angle.
C= 7 degree clearance angle.
G= tolerances for the various dimensional features.
T= info on how it mounts in the tool holder and the style of chipbreaker.
There are some more important numbers he did not include that determine the size and other physical characteristics of the insert and are important in relation to the holder into which they will be attached. The referenced table goes on to decode this info.
There are lots of styles of holders and obviously they have to be chosen carefully for the insert being used. SDJCR holders are specific to the DCGT style inserts in that they follow the 7 degree clearance angle of the insert. The supporting edge of the holder is slightly behind the bottom edge of the insert.
In use, the holder is usually set perpendicular to the lathe axis. This makes for the proper presentation of the cutter to the work and allows a facing cut by backing out the carriage.
There are also boring bars that accept this same insert. They can be handy for reaching into tight spots.
On a side note, I have this set of these:
http://www.arwarnerco.com/p-19-kit-16-3 ... -hand.aspx. This company specializes in HSS inserts and holders for those that wouldn't be caught dead using carbide.
And on another note, with a little research one should be able to find replacement cutters on the open market for the EasyWood lathe tools.
In my opinion the DCGT style insert is a good choice for what we are doing.
Hope this helps.
