Tom, Rivets have a plain shank i.,e smooth. If you have some 'rivets' with a
parallel multi fluted shank it is called a 'hammer screw' These need a
precisely drilled hole a fraction smaller then the flutes which allows them
to 'bite' into the edge. They are tapped home with a small hammer or a
punch. Because there is little resistance there is no danger of flattening
the head. They are usually made of Brass. Very difficult to remove too.
Rivets 'Setts' are used to stop the heads being flattened. They come in a
range of sizes to fit the heads. They can be made by drilling a small hole
in the end of a preshaped piece of 1/4 silver steel. The end is heated to
cherry red then a ball bearing is placed in the hole and given a good
accurate clout with a hammer. This forms a perfectly round hollow in the end
of the tool. The ball bearing should be the same size as the rivet head of
course and the hole drilled a bit smaller. Another way to avoid damage to
paint, headbadges etc is to use a jewellers pircing saw and cut the rivet to
length and slot it so it can be opened up inside the head. Mighty fiddly on
a 24'' frame!
Hope this helps. Mark Stevens Evanton Ross-Shire Scotland