A polypropylene training dagger from Cold Steel. You can beat these daggers to death and they'll survive pretty much anything you can throw at them (except for possibly storing them in the trunk in Texas in August - then they'll get a little noodley). The proper name for a training weapon, usually wooden, is "waster" (pronounced "waast-er, rather than waist-er), and the name (despite the elitist pronunciation), reflects that training weapons are expected to break sometime, i.e., "be wasted". Therefore, the declaration that these particular wasters are in destructible is a complete oxymoron, but here we are. I've been considering calling the whole product line "Unwastable wasters".
length: 19 3/4"
blade: 12 3/4"
blade width: 1 3/16"
blade thickness: 7/8"
grip and pommel: 6 3/8"
guard: 5 3/4"
weight: 12.2 oz
Listed and pictured here is the dagger version, also available are an arming sword waster and a longsword waster. All training weapons, be they synthetic, wooden, aluminum, or blunted steel have their advantages and drawbacks. These particular wasters are great for beginners, folks who really abuse their training weapons, and large classes/demonstrations where instructors need a quantity of identical simulators.
Price: $25 (dagger)
Price: $45 (pair of daggers)
Price: $120 (instructor's special - set of six daggers)
Price: $90 (longsword, arming sword, dagger set)