Thread: Better finish on brass

Hi all

I am in the process of turning some Brass, ( see att.)if possible I would like to, gain a better finish, I am using hand fed HSS hand ground tool
Can I use a knife edge type tool as can be used on steel or am I basically stuck with cleaning it up with emery paper once the machining is complete, also do I use the same parting tool as for steel.

P1010408.jpg

Are you using a negative rake tool?

No it is slightly positive

I've found that carbide inserts for aluminium (polished top and ground edges) work really well at high spindle speeds. Power feed is ideal, but if you can keep your hand feed smooth it's still a very good finish.
It's counter intuitive because they have a high positive rake, but they do the job

Try a negative top rake.

Thanks for the advice I will let you know what happens

When I’m watching Clickspring I always notice he has a very sharp cutting cool with a positive cutting rake. Way sharper than for steel or
Alu.

I’ve never turned bronze or brass but maybe try a cutting tool like that:




https://youtu.be/o8Bd8G21Vv8

Update, I ground a new tool and left it with no top rake made a big difference not a perfect but the best I can expect from my lathe, just leave a small touch up by hand.

Question No. 2 Should I grind the parting tool the same with no top rake or leave it as it is for steel, parting depth will be 5mm

Leave it neutral as well