mirror finishing

[leewald]

Hello. I am wondering how a person might polish a surface on precision ground shaft. I have done the best I can using "eagle one, mag wheel polish", but am not quite satified with the end results. Was wondering if there are any suggestions as to how I could polish it to a mirror finish. Or any suggestions on where I could post this topic if this isn't the correct place. thank you.

 

[unclesyd]

Comeback with a little more physical details like size, existing finish, and material.

Is this a one off or production item?

 

[leewald]

Thanks for replying. The product is a .75" shaft that is currently polished to a mirror like finish but one can still see the machining marks on it. The said marks are the ones that need to be removed. The material used is mild steel. I really can't be specific on that one. This is a single product, actually part of a mold for plastic parts.

 

[unclesyd]

Normally to get rid of machining marks you will have to take off more metal or if the marks aren't very prominent you can smooth and polish the existing surface marks and all. This is a judgement call

Give these people a call. They have some outstanding products and have always been quite helpful.

https://www.micro-surface.com/default.cfm?page_id=200

 

[kenvlach]

Another option, especially if you go undersize removing the machining marks, is chrome or electroless nickel plating. Steel molds for plastic are commonly plated for wear and corrosion resistance.

 

[EdStainless]

to polish you need to work down in steps with abrasives. start with 180, 240, 320, 400, 600, and so on. each time you have to remove all of the marks from the previous grit.
The other choice is to buff it and just smear the surface and hide the marks.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[Ron]

If the machining marks are like fine scratches on an otherwise mirror finish, you are at a stage where you can use a very fine grit of abrasive paper (finer than 600 grit) then follow with diamond paste on a cotton buffing belt or pad.