? for the mechanical types

I know a machine turned finish today is mainly just an astetic deal. Unless im mistaken though it was originally done for oil retention and the lessening of friction / wear on metal parts.

Thoughts on if it really does reduce friction etc? I could see how it could as super accurate machine tools are still hand scraped / flaked. You however dont hear about it used much unless im just not looking hard enough.

Have some projects and free time I might give it a whirl. If anything just as an experiment but thought I would ask anyone had any knowledge.

Many thanks and all that.

That depends greatly on what you are referring to... I work in a machine shop, finish marks very between 250 and 16, depending on what it is used for.

A lot depends on the type of product your meaning or dealing with.
It can be either depending on the part.
A machined part i=does have less friction, say a metal on metal contact like say a Piston and Cyl wall.
But you also have the other aspect such as a machined wheel face. More about the look.

Sorry all.... I should have said ENGINE turned finish. Not machining marks..... the swirls they intentionally put on metal surfaces slightly overlapping each other.
I always say the wrong thing

Well it's easy to do. Why not "give it a whirl" LOL.

Take a pencil with the eraser on it, dip the eraser in graphite and chuck it in a drill, place the eraser flat on the metal and turn on the drill, overlap the swirls in a fish scale pattern.

I have a few shops using a hone brush to make the cross hatch pattern. See link below.

http://www.brushresearch.com/brushes.php?c1=2

I have used a dowel rod with rubbing compound on it, chucked in a drill press.

"Jeweling"

A simple rotary wire brush will make bigger ones too.

I would say if there is constant lubrication that this type of finish is good. If only lubricated occasionally probably not good, smooth would be better.