Cessna 172 Maintenance Manual page 34

shank will turn with the drill and cause a tear. The rivet head will often break away and climb the
drill, which is a good signal to withdraw the drill. If the rivet head does not come lose of its own
accord, insert a drift punch into the hole and twist slightly to either side until the head comes off.
(4) Drive out the shank of the rivet with a drift punch slightly smaller than the diameter of the shank.
On thin metal or unsupported structures, support the sheet with a bucking bar while driving out
the shank. If the shank is exceptionally tight after the rivet head is removed, drill the rivet about
two-thirds of the way through the thickness of the material and then drive out the remainder of
the rivet with a drift punch.
The removal of flush rivets is the same as that just described except that no filing of the
(5)
manufactured head is required before center punching. Be very careful to avoid elongation
of the dimpled or the countersunk holes. The rivet head should be drilled to approximately
one-half the thickness of the top sheet.
Table 1. Approved Replacement Fasteners Chart
REPLACE
MS20470AD3
MS20470AD4
MS20470AD5
MS20470AD6
MS20426AD3 (Countersunk)
(Refer to Note 1)
MS20426AD4 (Countersunk)
MS20426AD4 (Dimpled)
CESSNA AIRCRAFT COMPANY
SINGLE ENGINE
STRUCTURAL REPAIR MANUAL
Inch thickness (or thicker)
0.025
0.020
0.050
0.040
0.032
0.063
0.050
0.040
0.080
0.071
0.063
0.063
0.040
0.080
0.050
0.063
© Cessna Aircraft Company
WITH
NAS1398B4, NAS1398D4
NAS1738B4, NAS1738D4
NAS1398B4, NAS1398D5
NAS1398B5, NAS1398D5,
NAS9301B5, NAS1738B4,
NAS1738E4, NAS1738D4,
NAS9301B4
NAS1738B5, NAS1738E5,
NAS1738D5, NAS9301B5
NAS1398B5, NAS1398D5
NAS1398B6, NAS1398D6,
NAS1738B5, NAS1738E5,
CR3213-5
NAS1738B6, NAS1738E6,
NAS1738D5, CR3213-6
NAS1398B6, NAS1398D6
NAS1398D6
NAS1738B6, NAS1738E6,
NAS1738D, CR3213-6
NAS1398B4, NAS1399D4
NAS1739D4
NAS1399B4, NAS1399D4,
CR3213-4
NAS1739D4
NAS1739B4, NAS1739E4
51-40-00
Page 3
Jun 1/2005