I see some pretty amazing prison art -- these guys can make anything out of anything. Some of the soap carvings and origami leave me scratching my head:
now how the hell did he do that? The fact that many of these individuals tend to make rather poor decisions (and thus, squander their talent carving bars of state-issued soap and molding chess sets out of toilet paper mache) pisses me off more than anything.
This doesn't seem to apply to weapons...a shank will only be used once, after all. If it's not found at the scene, the unit would be kicked in until it turned up or went out a window or down a toilet. The "new" technique involves grinding a point on a shard of Lexan on the concrete floor and either stomping it into the ground where it will be used (next to a walkway or in the yard, for example) or concealing it in a certain manner that's common knowledge but inappropriate to discuss here. It's a real concern because wanding and metal detectors won't find these, and if concealed as noted above, even a mild injury will be serious or possibly fatal if the inmate has HIV or hep.
I take that back actually -- there was a guy (not at my facility) who constructed a functional firearm out of some extremely common things that an inmate wouldn't have trouble getting ahold of. (And for that reason, the components won't be discussed. There's a certain amount of security in obscurity.) It was powerful enough to dent metal siding near his cell, which is how it was discovered. It wasn't pretty to look at but it was impressive all the same.
Folks get stripped out here whether they're coming or going. If it doesn't fit in an orifice, it stays where it is. I've never seen a tomahawk but it wouldn't surprise me.

Other places doubtless have other policies.