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 TB 55-1900-201-45/1
E-37. Hole Preparation. Where riveting is necessary and the rivet holes are punched, the holes should be reamed in
order to remove the excessively cold-worked material which can be a source of crack initiation. The holes need to be
reamed between 1/16" and 1/4" depending on the thickness of plate and the diameter of the hole. In most cases a ream
of 1/8" will be suitable.
E-38. Deterioration or Missing Rivets . The replacement of deteriorated or missing rivets, which were marginal in
size in original construction, with undersize bolts is unsatisfactory. However, upon approval by the Officer in Charge,
Marine Inspection, bolts may be used for emergency purposes if oversized and closely fitted into oversized reamed
holes. Often the ringing of rivets by means of welding is pro posed as a repair measure for leaking or otherwise defec-
tive rivets. Rivets which do not completely fill and are not firm and tight in their holes fail to effectively carry their share
of the load, and ringing with welding does not improve this situation. Accordingly, any ringing of rivets by welding must
be regarded as a temporary measure acceptable only where not more than a few scattered frame or seam rivets are in-
volved. Ringing of rivets by welding should not be permitted in way of lapped or strapped butts, or for any riveting of
deck plating outboard of the hatches. The use of welding in building up the deteriorated points of otherwise sound rivets
is permissible, however, provided the corroded metal can be and is removed prior to the time that the building up is
done.
E-39. Lock Pins. Certain types of lockpins have been accepted as a substitute for hull structural rivets. Unless lock-
pins are specified on an approved plan, they should not be used in repair applications without consulting the Comman-
dant (MMT) or a field (mmt) office. See NVIC 3-63 for further information on this subject.
E-29
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