How are bolt cutters manufactured?

28th February 2020


How are bolt cutters manufactured?


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		Bolt cutters are heavy duty tools which are factory-made with precision machinery and high-quality steel. They are made by a process called “drop forging”, where the metal is heated up and then pressed into a mould, called a die, by a falling or powered hammer dropped from above (hence the name “drop” forging). This method is used because it aligns and stretches the grain of the metal in a special way which results in a stronger tool with a longer lifespan than those cast from molten metal or machined (cut from a block).

		Blades
		After forging, bolt cutter blades are subjected to two further processes, hardening and tempering, which give them the extreme level of strength that they need.

		Hardening In the first stage (hardening), each blade is heated with a gas torch (or by machine) until it glows red. This occurs above 480 degrees Celsius (900 degrees Fahrenheit).

		It is then cooled rapidly in clean water, which results in it becoming very hard, but more brittle.

		Tempering The second stage (“tempering”) reduces the brittleness of the blade and leaves it more supple and resilient. This time the blade is heated only to a limited point and then the heat is removed and the tool is allowed to cool more slowly. At the end of this process the blade should be tough and hard-wearing and unlikely to snap.

		Handles
		Drop forged Where the handles of bolt cutters are solid they will have been produced by the same method as the jaws, i.e. drop forging. This makes for a very strong, solid tool which will last a long time, if looked after.

		After being forged, the handles are given a paint finish in a process called powder-coating.

		Cold roll formed Longer handled versions of bolt cutters are now often made of tubular steel. This is steel which is “cold roll formed” (rolled by huge machines at room temperature) into tubing. This kind of metal is strong, and lighter than drop forged steel, making it ideal for long-handled cutters, where the handles are under greater pressure when in use.

		Handle grips
		Most long bolt cutters have tough, hard-wearing grips at the end of the handles. These will have been moulded out of rubber or vinyl and fitted by machine over the metal handle.