Some materials which might require cutting are made of hardened steel, which has been tempered (usually heated with other subtances and then rapidly cooled). These materials are usually resistant to bolt cutters.
Some padlock shafts, for example, are made of hardened steel. This kind of strong, rigid product can be tackled instead by the powered cutters below.
An angle grinder can successfully cut through hardened steel because, rather than attempting to slice it, its fast-spinning blade grinds the metal and eventually cuts right through it.
Hand-held rotary cutter
A hand-held rotary cutter is small and easily-manoeuvrable. It is therefore useful for narrow spaces where an angle grinder cannot fit. It performs the same job as an angle grinder, rapidly filing off tiny flakes of material until it cuts right through.
Diamond or carbide-tipped circular saw
An industrial power saw with a diamond-edged or carbide-tipped blade will cut through hardened steel.
Hydraulic bolt cutters
Another alternative to manual bolt cutters is a set of hydraulic bolt cutters. These are often used by the emergency services in rescue situations where fast, high powered jaws are required to force entry or cut away obstructions.
Hydraulic bolt cutters can deliver a cutting force of up to 11 tonnes and can cut through high-strength metals such as rebar (steel reinforcement bars used in building) and heavy padlocks and chains up to a diameter of 16mm (5/8″).