BEST METHOD FOR SMALL, TIGHT TOLERANCE, HOLES

[YCENG]

I need to make two .0275" holes in a .120" thick plate, with a hole diameter and centerline tolerance of +/- .00005", or better.

I was thinking of making the plate of either carbide or 440C 54-56RC.

Is jig grinding the best method for making these holes?

Is one material better than the other for the tolerances I’m trying to get?

Thanks for any input you can give me.

 

[ctopher]

It can be done.
Is it machined in house or outside? Ask the machine shop where it will be machined if they are capable of the tolerances.

Chris
SolidWorks 09 SP4.1
ctopher's home
SolidWorks Legion

 

[YCENG]

Chris, I am having these parts made outside. Typically I would send these off to an EDM shop, but I'm thinking EDM might not be the best process for getting small, tight tolerance holes.

 

[KENAT]

forum281 might be a place for this if you don't get an answer here. +-.00005" between hole centers & on diameter is pretty tight.

Might want to find a 'micro machining' specialist.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[TheTick]

Sounds like a fiber-spinning operation. Yes?

 

[MechEng2005]

Wow. That is really tight tolerance... I'm surprised that it can be done as "easily" as implied by the responses. Then again, I work in a much more "sloppy" industry and can count on one hand the number of non-default titleblock tolerances I see in a typical month...

I recommend a material that doesn't change in size much with temperature.

-- MechEng2005

 

[SDETERS]

Can you machine the part to get it within +/-.0007 or so then press a steel ball through the hole to get the size correct. This works on thin shell parts but I do not know how much material you have around the two holes.

 

[ewh]

You should either provide a link to your other post asking the same question, or red flag one of them.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]