skydiverlv
Well Known Member
The T-407 backing ring is required countersunk for attachment to T1202 forward
tank bulkhead which is required dimpled at same locations to be mated together
with 426AD3-4 rivets. I have countersunk T407 with 100 degree bit and the ring does not mate well with the dimples. Will T407 need 120 degree countersink holes to mate properly?
tank bulkhead which is required dimpled at same locations to be mated together
with 426AD3-4 rivets. I have countersunk T407 with 100 degree bit and the ring does not mate well with the dimples. Will T407 need 120 degree countersink holes to mate properly?