AIA/NAS NAS 609-1962 (Rev. 3)1962年4月取代(非首选螺纹)帽套筒扳手头螺钉 [代替: AIA/NAS NAS 1351, AIA/NAS NAS 1352]
Screws-Socket Head Cap (Non-Preferred Thread) Superseded - April 1962 (Rev. 2) [Use: AIA/NAS NAS 1351, AIA/NAS NAS 1351, AIA/NAS NAS 1352, AIA/NAS NAS 1352, AIA/NAS NAS 1352]
Lengths above top heavy Iine are threaded as
close to head as practical.
Lengths between heavy lines are threaded:
Coarse threads = 2 Diameter + 1/2 inch
Fine threads = 1-1/2 Diameter + 1/2 inch
Lengths below lower heavy line are threaded:
Coarse threads = 1/2 length
Fine threads = 3/8 length