Tool angle terminology

Hi There

Can anyone confirm the correct terminology for tool angles. It seems to vary in different books and possibly between the UK and USA.

regards David

David, here is an extract from my apprentice bible "Engineering Workshop Data" published in 1956 by Caxton.

Hope it helps.

Len.

US (North America actually) terminology is probably best illustrated by the entry in Machinery's Handbook .... there are differences from both David's and Len's definitions. For instance, "Top Rake" is called "Back Rake" and "Side Relief" is what in David's illustration is called "Side Clearance".

I have the 28th Edition of MH (desk edition now to go with the eyesight). However, I also have the facsimile copy of the original (1914) edition which uses such terms as "back slope" and "side slope"

David,

The generally accepted terminology used in Australia; side rake, side clearance & front clearance are the same as in your sketch, with top rake referred to as back rake, front relief referred to as trail angle & side relief being approach angle. The approach angle in the sketch being negative. Possitive approach angle, angled toward the right when viewed from the top of the tool.

Regards,

Don.

Hi All

That is the problem, not standard terminology and I need to get it right as it is for a book.

regards David

Certainly what you show in your original post will be understood in the UK and Oz, probably even in NZ

Hi David,

That would be correct as far as the UK is concerned and would be understood by any engineer. This is the terminology from my venerable Chapman, 'Workshop Technology' Vol 1:

Regards

Terry

Edited By Terryd on 29/05/2012 10:49:36

Thank you all, that looks like it will do, suitably redrawn.

I have been grinding tools for years but never bothered about what the angles were called.

regards David

Due to laziness I often use the same knife tool for turning and facing. Should I keep swapping the names of the faces?

Russell.

Hi Russell

Only if you swap the tool around by 90 degrees in the tool post.

regards David

I agree with Terry and the Chapman version but would like to add "cutting edge" for clarity to beginners. Colin