According to Quirrel, Draco's padlocked-glove-Colloportus trick would withstand 'lesser material forces', implying that it had, at the least, limited tensile strength. (Infinite hardness would be less wierd.)

I don't see why partial transfig should be any easier to break locking spells with.

If Transfiguration can create prestressed objects, (and Partial Transfig almost certainly can) it should be possible to make some very powerful one-shot equipment without liquids or gases. (this includes the transfiguration grenade I mentioned elsewhere.)