Tools help - buying advice

[DaveH]

(11-14-2014, 10:03 AM)ironman Wrote: Im looking around for tool bit holders. Are there different sizes on the bits itself?
The ones i have today is from KOMET. Here are some of the numbers that are on the boxes:
P1-R-P25
P1-K20 N
P1-L-P25

What does the numbers say?

Ironman,

I think - (I only think) those numbers refer only to the type of carbide and the material they are designed to cut. ie P25 for steel (turning), the carbide is a medium toughness and medium wear resistance.
Now P25M is the same as above but for Milling.
K20 N for cast iron the N, I have no idea.
There web site should give more info.

This is where it all goes to pot and becomes complicated and I can explain why.   Most if not all inserts are made to machine to a specific purpose - whether it is  material types, types of cut and so on. The inserts companies make them for industry and for industrial use not for hobbyists however this does not mean we cannot use them, we can provided we choose the correct insert suited to our purpose.
As hobbyists TIME isn't a major concern regarding the manufacturing process nor is taking massive depths of cuts. So choosing an insert that is capable of taking 3mm depth of cut, will probably give a rubbish finish when trying to take a couple of cuts of a few thou finishing cuts. (Might not want to cut at all )

There are trade offs with hardness, toughness, how sharp the cutting edge is, wear resistance these parameters seem to work against each other nevertheless if we choose the inserts with care, we as hobbyists can nearly get a "general use" insert. The development of inserts is on going and they seem to improve every day and over the last 15 years I have seen a vast improvement.

Just to say I only use ISO inserts (and holders) the main reason I can buy inserts to fit my holder from most insert manufacturers and I am not tied down to a specific manufacturer.

There is a start.


DaveH