The International Criminal Court is a hand grenade with a very loose cotter pin.
From the washingtontimes.com
For pins that have a cross-hole in the threaded end a cotter pin can be used.
From the en.wikipedia.org
Spencer also invented a precursor to the modern paper clip, though it looked more like a modern cotter pin.
From the en.wikipedia.org
A bowtie cotter pin is a formed wire fastener that resembles an R-clip, except it positively locks when installed.
From the en.wikipedia.org
One 18-year-old patient with repetitive behavior had self-embedded 35 objects over two years time, including staples, a comb tooth, a fork tine, a cotter pin and nail polish wands.