The Cessna 120-140 Association Forum

I have a project 46 Cessna 140 , I got it just needing and engine and mount, does anyone know the bolt size of the bolt mounting to the firewall, in the Cessna manual its described as a NAS145-15 internal wrenching that is a Cessna part no. Called Univair and they do not know what NAS is. Thanks

https://www.univair.com/hardware/bolts/ ... hing-bolt/

Odd I did a search and the Univair site came up.

John C will chime in shortly, there's an equivilent MS number for the NAS bolts.

MS20005-6

NAS is National Aerospace System, a universal standard, not a manufacturer's designation. It has been largely replaced by MS (Military Standard) numbers.

The "dash" number on the NAS bolt signifies the overall shank length in 16ths of an inch. The dash number of the MS part is the grip length (the shank less the threads) in 16ths.

Univair has the NAS145-15 bolt for $43.92. Try Military-fasteners.com for the MS20005-6. They don't seem to list a price but Google thinks it's $14.55 each. You could also try Fastener Dimensions in Pennsauken, NJ. None of the usual suspects seem to stock it.

Very helpfull Thanks