Cessna 172 Maintenance Manual page 43

B. Soft ("A" 1100 aluminum shank rivets or "B" 5056 aluminum shank) rivets are also used to install non-
metallic parts. Original equipment soft rivets will be either red or green colored under the paint. If the
butt or driven end of the rivet is adjacent to the non-metallic part, it is preferable to install a washer over
the shank to prevent the rivet shank, which swells during driving, from overloading the non-metallic
hole. The hole in the washer should match the specified installation hole for the fastener. If the tail
end of the rivet is installed through metal substructure, the washer is not necessary. Take care when
driving rivets through non-metal to not overdrive the rivet. If the rivet is overdriven, the shank will swell
even with the washer in place. The rivet butt should be driven to no more than necessary to retain
the part, never more than 1.4 times the shank diameter.
C. If the original equipment rivet provided connection between metal parts as well as non-metallic parts,
it may be a standard (AD) rivet. Original equipment AD rivets are colored gold or uncolored. Replace
original equipment AD rivets with AD rivets.
CESSNA AIRCRAFT COMPANY
SINGLE ENGINE
STRUCTURAL REPAIR MANUAL
© Cessna Aircraft Company
51-40-00
Page 12
Jun 1/2005