Developing a method of inspection (other than visual)

[Jim Biz]

:thedeal: I have been charged with finding OR developing a method of inspection (other than visual) to include the following at two stages of production:
1) raw materials receipt
2) outsource "preship" inspection

The inspection criteria for the plated tubing will be as followed.
1. Rust free
2. No nick, scratch, ding or burr on the surface of tube exceed 0.55 mm (0.20") in heights or depth.

#2 is a part of ASTM A500-9. I also reommend to have a visual check for straightness inspection for your incoming tubing.

This is 3.5" round thin wall (0.215") tubing mill grade C - we recieve in 20 foot legnths...

"Of course" our internal criteria for the developed method would include - no addition of labor time - and no addition of mechanical testing equipment - no-destrictive testing.

Any thoughts would be appreciated.

 

[gpainter]

On raw materials get a certificate of compliance from your supplier that the material ordered meets or exceeds your criterion.

 

[Jim Biz]

Saddly - Certs are an automatic part of our system.
These are being viewed at present as not acceptable evidence form a customer viewpoint.

 

[JRKH]

CURIOUS

Why a non-visual inspection?

 

[Jim Biz]

The spec we are under outlines no surface burrs/scratches/nicks higher or lower than .55mm - (0.20") - visually distinguishing between .010-.015 ore .025" the heigth/depth of a nick -- burr.. etc.

Would be arguable at best

 

[CarolX]

tough one

Jim,

2 methods come to mind

1) Visual comparison to a known standard

2) Depth/height measurement with a microscope.

Best I can pull out of this tiny mind today.

Regards,
CarolX

 

[E Wall]

Inspection Method??

If your not going to use optical measuring equipment, and visual's aren't reliable...what about a simple test.

Burr Inspection: Buy cheap hose, streach over a hand and run it the length of the tube...If no snags or runs are created in the hose - Pass.

Nick Inspection: ? Unless the nick creates flange/burr press silly putty or play dough in it and measure the impression?

Okay, all kidding aside, How on earth are you to come up with an inspection method that takes no manpower, no time, no equipment without making it someone else's responsibility (supplier)?

Additionally, if the problem is suppliers are not meeting the spec criteria...Who is evaluating your suppliers and to what criteria?

This doesn't seem like a realistic goal, but maybe I'm just too naive in this matter....I'm waiting to see what you come up with.

Good luck!

PS: For the #2 Straight test....Old pool cue test - roll on level surface and see if it wabbles

 

[Jim Biz]

Great test question for the Challenge Warrior huh??

What I (intentionally) left off in the origonal post was that there also is a Mill - tolerance- VS-customer expectation issue involved with all of this...

From the Suppliers viewpoint - ASTM spec declares in plain english "any surface nonconformance under/over .020" are not cause for reject" - that is true - little fault can be placed from their end.

Customer declares - "we know that is what it says" but it's not acceptable for our application - difficult to"upgrade" the material specification due to costs.

Frankly - the Hose test (or other cloth medium) if we record "by the foot results" and properly document the frequency) might just work...

I'll keep it in mind.

 

[JRKH]

Jim,

I know your criteria says no new equipment, but it made me think of a noncontact, surface measurement gage I saw some years back. It uses a light beam and measures the reflection of the beam to determine Ra values. It was designed to be used to measure surface finish on aluminum rolls for the airline industry.

I just can't remember who made it.

James

 

[Jim Biz]

Well as of right now - I'm planning or at least attempting to explain that this really can not be done without investment of some nature.

If you remember even the name of the device - I'll do some research... (even the Nylons (hose) method would need to be paid for...

With any luck I can get the criteria expanded to minimum - cost effective input.....