External Thread Cosmetic/Appearance

[ewpiii]

Hello. I work for a medical device contract manufacturer of primarily components. We are a print to part manufacturer for larger medical device OEMs.

We have had debate over thread "appearance" on thread we manufacture. one customer is asking us to help them with THEIR part regarding the appearance (ie. small flat, dings, etc ) on the threaded region.

I am looking to see if there is any ASTM or similar spec to support inspection of threads for cosmetic/appearance etc. From the form, fit or function side, if the GO thread gage stops at a "flat, ding etc", we fail the part. BUT if the GO gage goes along nicely and is not affected by the cosmetic anomoly I am inclined to pass the part.

Thoughts?

Thanks: Ed

 

[Jim Wynne]

Hello. I work for a medical device contract manufacturer of primarily components. We are a print to part manufacturer for larger medical device OEMs.

We have had debate over thread "appearance" on thread we manufacture. one customer is asking us to help them with THEIR part regarding the appearance (ie. small flat, dings, etc ) on the threaded region.

I am looking to see if there is any ASTM or similar spec to support inspection of threads for cosmetic/appearance etc. From the form, fit or function side, if the GO thread gage stops at a "flat, ding etc", we fail the part. BUT if the GO gage goes along nicely and is not affected by the cosmetic anomoly I am inclined to pass the part.

Thoughts?

Thanks: Ed

This is the first time I've heard of anyone making a complaint about cosmetics on screw threads and I've been at this a long time. I know of no standard for anything other than dimensional and functional requirements. If your customer wants to push the issue, they need to come up with objective criteria and be prepared to pay for it.

 

[ewpiii]

Jim: We are close to this point for the price vs cosmetic "requirements" and the customer is asking if there is a spec they should expect for thread cosmetic appearance. With all the operations our parts go through in batches and cleaning/handling etc, sometimes small issues arise on the thread peaks. They initially rejected parts that threaded well but had some minor blemishes. We pushed back and are trying to nail it down with them. Subsequently we can define our own internal criteria AND method for threads.

Thanks Jim Any more input out there folks?