I once broke a shear pin after a length of old sump pump discharge hose buried under a snow pile became entangled in the auger blades. The spare shear pins were missing, so I figured I'd take a cheap steel 1/4-20 bolt and grind it down until its just about a 1/16 of an inch diameter at the point where the auger tube and drive shaft meet. It did not work as the following snow fall I hit a rock and the damn thing jumped violently and I let go of the drive clutch which prevented it from completely self destructing. The auger tube hole was gouged from the screw on both sides, the screw bent into a Z shape and the housing was slightly bent askew. After some reforming in my shop it was working fine again and still runs to this day. That Craftsman 5HP blower has taken a hell of a beating, is in rough shape but still runs. I keep wanting to up the HP a bit but its seen enough abuse.

Pro tip: always winterize the engine to keep it running for years. Drain the fuel completely, and drain the carburetor bowl. Pull the spark plug and put a cap full of motor oil in the cylinder and gently turn the engine over by hand using the pull cord to coat the walls. Also helps to tape over the exhaust and stuff the intake port with steel wool to keep critters out of the passages. I once had a generator suddenly stop working and upon pulling the plug found a dead spider across the electrodes which shorted it.