Indexable tips and their use

I have to admit to being a little confused when it comes to understanding the "fit for purpose" of any one of hundreds of different types of tip that one comes across when browsing the subject generally.

So if I look at say - DNMG - I see that the N indicates zero rake. Is this type of tip intended to be used on a holder with a canted / angled seat which in itself may provide the necessary "attack" -------- or what?

Rik

N is the clearance angle not the rake on the top of the tool so it could still have positive rake and be able to fit a flat topped holder though often used on one with a 5deg or so slope on the seat.

Edited By JasonB on 30/04/2015 19:03:29

Well, I am also having a bit of an adventure, but with Indexable Milling cutters. It's given me a headache to be honest. I am also building a couple of toolholders as I have found a couple of boxes of "Valenite" brand turning tips and if I didn't know better, I would say they are Imperial. The tips are from Canada so could well be. Anyway, I will never get a toolholder for them and I have sufficient to make it worthwhile making tooling.

graham.

The Milling tips are SNMM 090308 EL and the Turning tips are TNEG 2521 so if anyone can proffer any clues as to what they are or the breakdown of the nomenclature I would be extremely grateful.

I blame bloody Rik anyway because his post about making tooling for the tips started the brain worm going - I knew I had a good couple of boxes stashed somewhere

graham.

How's this?

**LINK**

I tend to use the charts on page 452 & 453 in this catalogue as they are the ISO codes rather than the American codes found in the Carbide dept charts

I have all the same questions. Hopefully the mooted Workshop Practice Series book discussed here will address all these issues and more.

Just sharpen a peice of HSS and forget tips, after all this is model engineering. Old curly would turn in his grave at thoughts of this kind😀

Let him spin; although I suspect it would be at a speed more appropriate to carbon steel tooling rather than HSS given that he started before WW1. So to stay true you shouldn't really be using HSS.

Andrew

The tip next to the tool holder is one o the 16 mm tips that I use in the face cutter on the milling machine, I usually use these tips on the lathe after they have been used on the mill. Sorry it's a bit fuzzy

Ian S C

So looking at the(site data) rake angles given you need a heavier rake on the tip the smaller the diameter of the job in hand?

Edited By Jesse Hancock 1 on 01/05/2015 18:03:45