As said before, AN bolts are fine threads. Fine threads are seldom used in castings. If it is 3/16" it would probably be a 10-24. If it is 1/4" (most likely) it will probably be a 1/4-20. If it's 5/16", probably 5/16-18.
Mel Asberry, DAR since the last century. Over 1,000 certifications accomplished. Discount for Veterans, Law Enforcement, Fire Fighters.
EAA Flight Advisor/Tech Counselor, Friend of the RV-1
Recipient of Tony Bingelis Award and Wright Brothers Master Pilot Award
USAF Vet, High School E-LSA Project Mentor.
RV-6 Flying since 1993 (sold)
Last edited by Mel : 06-27-2021 at 11:34 AM.