A5 thread size confusion

[Wartex]

I am reading a bunch of resources that claim a5 barrel thread is 7/8-20 UNF. Well, there is no UNF die but only UNEF in that size. So i bought 7/8-20 UNEF die but if i try to chase a barrel it starts cutting the 3rd turn on the crest, so it tells me its not 7/8-20. I took it to a local machinist and it seems its closer m22x1.25 after some measurements. What am i doing wrong? What is the true a5 thread size?

[nerdcore]

M22x1.25 is the G7 Fly Angel barrel threads, according to Ydna: http://www.zdspb.com/tech/misc/cadfilepost/barrels.html

The barrel you tried may not have been an A-5 barrel.

But also, UNF ≠ UNEF. UNEF has more threads per inch. They EXTRA fine 😏

[Wartex]

The TPI is dictated by number, so 7/8-20 is 20 TPI, unf or unef doesnt matter

[Brokeass_baller]

UNC = coarse threads
UNF = fine threads
UNEF = extra fine threads.

[William the Third]

Tap and dies have different levels of tolerances. It is possible for a correct sized tap/die to still remove material when chasing threads due to this. Additional processes, like anodizing, will also change tolerances.

[Ecapnation]

Most barrel threads aren't cut with a dye. They are single point turned on a cnc lathe

[William the Third]

Another good point.

[Toestr]

I checked an A5 barrel with a thread gauge and it's definitely 20 TPI.

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