Typical ways of bypassing Diazed fuses are wire (individual strands) wrapped around the ceramic body or a nail driven through the metal end caps and ceramic body. The worst kind is usually found in metal shops with a lathe, a solid metal bottle "fuse".
I've been guilty of "repairing" a 20 amp fuse myself, although I knew it only fed a single motor with additional protection of a 25 amp MCB upstream. The MCB was the actual protection for the old motor, the fuse was only necessary to avoid changing the historic wiring (ca.-1920) for a quick test run. Doing that I discovered that a single strand from a 1,5 mm2 conductor probably takes around 16 amps, maybe a bit less - it blew within less than a minute. A second strand fixed that issue. The next time we ran the motor we fitted a proper fuse of course.
