A Tale of Two Mil Specs: Mil Spec A-A-58092 and the old Mil Spec T-27730A
What is Mil Spec A-A-58092?
We are glad you asked. Mil Spec A-A-58092 is the new specification for Polytetrafluoroethylene. People have been using and quoting based on the old T-27730A spec for so many years most do not realize it is history. Effective 9 February 1998 Mil Spec T-27730A has been canceled and was replaced by Mil Spec A-A-58092.
We applaud this move by the Defense Department. Mil T-27730A had no teeth whatsoever. Basically, if it was white, it met the spec. We've seen some absolute garbage that met that spec. But Mil Spec A-A-58092 calls for specific specifications for density and quality. It is very stringent. While our M66 product comes close, Merco M77 Full Density Threadmaster® Threadseal meets the spec with flying colors.
Allow us a moment on our soap box: very few PTFE thread seal tapes meet this spec.
What is Mil Spec T-27730A?
We can tell you what it isn't, and that is current. See above. We can also tell you it was another government boondoggle. As we said above, make it white, make it 1/2" wide and make it cheap. And we have seen some product so bad we wouldn't recommend it for fixing a vanity sink. (Yet it does technically still meet the spec.)
So tried and true works, but there are frequently better ways to do stuff. Our two great grandfathers here probably reigned terror on guys in the other trenches. But what was tried and true in 1918 won't keep a B-1 Bomber up in the air.
below Wilson's Sec. of War Newton D. Baker really checking out the requirements in the field: France, 1918