Countersunk Blind Rivet Flushness Against Surface
Countersunk Blind Rivet Flushness Against Surface
(OP)
Hi there!
I am working on an aluminum shelter that involves about 55,000 various rivets. The particular rivets I have a question on are NAS1921 rivets, 100 degree flush head countersunk blind rivets. We use various size and grips lengths along with an internal installation spec, heavily referencing MIL-STD-403C but it doesn't specify a 'flushness' requirement or guideline. I also referenced the Huck Unimatic Blind Rivet catalog with no such luck either.
Our internal document does state "The countersunk rivet head shall be flush with the riveted surface within +0.005 - 0.008 inches." However being engineers there is debate whether that ranges from -.008 to +.005 inches or from +.005 to +.008 inches and I can't trace back where these dimensions originated from.
Does anybody know what are the limits of how flush the manufactured head should be against the skin after the rivet is installed or are there any? A referenced document would be great too!
Thanks for any help.
I am working on an aluminum shelter that involves about 55,000 various rivets. The particular rivets I have a question on are NAS1921 rivets, 100 degree flush head countersunk blind rivets. We use various size and grips lengths along with an internal installation spec, heavily referencing MIL-STD-403C but it doesn't specify a 'flushness' requirement or guideline. I also referenced the Huck Unimatic Blind Rivet catalog with no such luck either.
Our internal document does state "The countersunk rivet head shall be flush with the riveted surface within +0.005 - 0.008 inches." However being engineers there is debate whether that ranges from -.008 to +.005 inches or from +.005 to +.008 inches and I can't trace back where these dimensions originated from.
Does anybody know what are the limits of how flush the manufactured head should be against the skin after the rivet is installed or are there any? A referenced document would be great too!
Thanks for any help.





RE: Countersunk Blind Rivet Flushness Against Surface
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Countersunk Blind Rivet Flushness Against Surface
RE: Countersunk Blind Rivet Flushness Against Surface
Racook, these are missile command specifications and this unit is part of a missile command system however this is a mobile-land unit. I don't have a choice in the matter for the small tolerances as they are set in stone and are near impossible to change, however with my experience on this unit these tolerances are necessary.
RE: Countersunk Blind Rivet Flushness Against Surface
So unless you can find a standard that matches your spec and just clarifies ++ or +- then it won't be much help.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Countersunk Blind Rivet Flushness Against Surface
Yes I realize that fact of precedence, hence this post to attempt to trace back those values if they exist somewhere. Just simply having other referencing information would give me leverage to updating our own specifications if...more likely when, an issue occurs.
RE: Countersunk Blind Rivet Flushness Against Surface
Ted
RE: Countersunk Blind Rivet Flushness Against Surface
RE: Countersunk Blind Rivet Flushness Against Surface
RE: Countersunk Blind Rivet Flushness Against Surface
RE: Countersunk Blind Rivet Flushness Against Surface
MintJulep - Fortunately we only spot check the rivets but there are many we check.
1gibson & hendersdc - Lol