After much searching at Harrogate managed to find a couple of 5/8 shank brazed tip parting off tools. Both "toolmex" which I've had before.One is blue painted & stamped P20, the other is red & stamped K20. The stallholder had no real idea what the diference is. Both tools appear to be ground identically, so it must be tip grade / material suitability, have a vague idea that I should know this, but don't ! any ideas? Average show otherwise. Mark G.
Carbide Grade?
May 06, 2005
5 Replies
2nd hit on Google....
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Peter
OK, but from chart I see not much difference between "P20" & "K20", so do I continue as normal and select tool by smell/mood/whichever is nearest. Thought that for a change( as both tools ground the same) I'd try and use the best for material. At a guess I'd say the P grade being 0.5 RA harder than K would suit cast iron / brass better, and K for steels ??? Mark G
Best to go with your feelings IMO, not as if you are doing bulk production work where material removal rates are critical :-))
Peter
Blue P20 Roughing of steel and steel castings using moderate to low cutting speeds under unfavourable conditions. A general purpose grade for small workshops where a variety of steels are machined.
Red K20 Finishing and light roughing of cast iron and other short chip materials using fine to moderate feeds and moderate to high cutting speeds under favourable conditions. This grade is also suitable for milling operations.
-- Regards,
John Stevenson Nottingham, England.
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So long as the swarf is blue and not red it is about right.
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