There's something called [link|http://en.wikipedia.org/wiki/Shot_peening|shot peen] that is a process in which tiny ball-bearings are applied to metals in a process like sandblasting. It serves to harden surfaces (e.g. in connecting rods of racing engines.) IOW, peen is also a verb.
[link|http://en.wikipedia.org/wiki/Ferrule|Ferrule] is also the name of a tapered ring in a tube fitting used to ensure a leak-tight seal that can be disconnected and reconnected several times. It's also the name for a metal clamping ring around cables, etc., to keep them from fraying and to tie them around bushings, etc.
Another list of obscure words is [link|http://www.kokogiak.com/logolepsy/|Luciferous Logolepsy].