Drawing Note or Specification 2

[m60gunner]

Are there any industry standard notes that can be applied to a mechanical drawing that specify the cleanliness of the detailed part?

I am looking for something that covers the cleanliness of a delivered part... particularly an accepted level of particulate/contamination, size of particles, etc. Maybe a size range and number of particles that can be found on a part.

I am sure that I can come up with something, but does a standard exist, or a general set of notes that can be applied to a part drawing? Possibly similar to a clean room class level spec?


Air cooled, belt fed, gas operated machine gun firing from the open-bolt position

 

[Cockroach]

Yes, you can do this several ways.

Specify a surface finish will automatically cover cleanliness for obvious reasons. Probably 125 Ra will work for your application, 250 Ra may not. I use notes in the lower left hand side of the drawing and mark the location of cleanliness with a bubble and leader. You could say something like "remove loose surface scale & rust by hand". Maybe you need machining to that surface finish to do the job, it depends on your application and what you want.

Hope this helps.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[KENAT]

I asked the same question a while back thread1103-165640 and discovered....

There was a MIL-STD-1246C which covered this. (can find on web)

This has been replaced by IEST-STD-CC1246D Product Cleanliness Levels and Contamination Control Program.

Essentially they have defined classes of surface contamination, i.e. X particles of size Y per square foot.

Also covers non particle contamination if you choose to call it up.

 

[Timelord]

Here is a copy of MIL-STD-1246C

http://www.ligo.caltech.edu/~coyne/AL/SYS/ref_docs/MIL-STD-1246C/MIL-STD-1246C.pdf

Timelord

 

[KENAT]

The mil std is no longer current so you shouldn't really reference it on a drawing. The categories are basically the same in the IEST-STD.

The below is the note we've been using. Level 100 may not be appropriate for your needs.

PART TO MEET CLEANLINESS REQUIREMENTS OF IEST-STD-CC1246D LEVEL 100. IF NOT TO BE USED IMMEDIATELY THEN TO BE ENCLOSED IN PACKAGING TO IEST-STD-CC1246D LEVEL 100 LABELED: “CLEANED, DO NOT OPEN OUTSIDE OF CLEAN ROOM”.

 

[JStephen]

You might consider also how this is to be tested or measured. If you don't have any way to confirm compliance with the standard referenced, or the supplier doesn't, it won't do much good.

On the roughness testing- I would think this could miss oil or stains of various kinds, and even loose powder- would take some work to see if it really covered the situation.

 

[KENAT]

JStephen is not wrong and I've had at least one phonecall along those lines. If I recall the standard does give guidance but that requires having a copy of the standard. Also some companies may still not have the required equipment.

Our first attempt at cleanliness note was (most of our stuff is fairly small hence the 'in bag').

PART TO BE FREE OF OILS, LUBRICANTS AND OTHER CONTAMINANTS PRIOR TO BEING PLACED IN SEALED BAG.

We still include this to cover non particulate contamination but it doesn't give a pass/fail criteria so isn't very good. If you look close enough i suspect just about anything would fail, not matter how clean it appears.

 

[RebelBrill]

While I haven't checked it, or used it recently, I believe ASTM A380 offers guidance on cleanliness specification and cleaning methods.

 

[KENAT]

ASTM A380-99e1
Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems
ASTM International

I don't believe this will give the information m60Gunner wants.

While by definition passivating etc will usually clean particles off an item it's not a requirement. There is nothing stopping it getting contaminated again after cleaing. Suggest the IEST-STD is the way to go, only problem is making sure it is worked to (as JStepehen), you'll have to get your QA dept to buy in and monitor this.

 

[IRstuff]

NASA has a spec as well "JSC SN-C-0005RD CONTAMINATION CONTROL REQUIREMENTS" located here:

http://snebulos.mit.edu/projects/reference/International-Space-Station/SNC0005RD.pdf

TTFN

 

[m60gunner]

A380 is a nice guideline for the cleaning of parts prior to passivation, but I am looking for something to serve as a reference for parts coming into my facility. I think KENAT is pretty close. I need to convey that the parts are to be clean room ready prior to going into the clean room whether the vendor does it or we do it via a part traveler/process work order.

Thanks for everyone's comments!


Air cooled, belt fed, gas operated machine gun firing from the open-bolt position

 

[KENAT]

m60gunner

Mine was for clean room too. Our clean room is class 10000 (nearly 1000 on a good day, at least it's meant to be) and the plenums of the actual tools we make get down to 10 or even 1.

I'm not at work today so don't have our standard notes to hand but I think we selected class or level 200 (can't remember the terminology). Our note also says that if not to be used imediately the part is to be put in packaging of the same level of cleanliness.

If I remember I'll post our note on Monday.

The NASA one might work for you, I looked at it when I did my digging but for clean room stuff I think the IEST std is more rigid/better defined.

 

[KENAT]

PART TO MEET CLEANLINESS REQUIREMENTS OF IEST-STD-CC1246D LEVEL 100. IF NOT TO BE USED IMMEDIATELY THEN TO BE ENCLOSED IN PACKAGING TO IEST-STD-CC1246D LEVEL 100 LABELED: “CLEANED, DO NOT OPEN OUTSIDE OF CLEAN ROOM”.

I obviously remembered wrong, it was level 100. Hope it helps.