The jaws form the head of a pair of bolt cutters and are forged separately from the handles. The part of the tool where the blades are connected to the handles is called the neck. They are secured in place by a pair of bolts. By contrast, compact bolt cutter blades and the handle diagonally opposite are forged in one piece and connected by a single bolt, much like a pair of scissors or shears.
Blades
The blades are the actual cutting surfaces of the jaw section. They are made to be extremely hard and they come in a variety of configurations (such as centre cut or shear cut) to make them suitable for different uses.
The multiple joints on most bolt cutters are vital to the tool’s strength, as they compound – or multiply – the force applied to the handles.
There are three key joints: the handle bolt (which connects the two handles), the middle bolts (which attach the jaws to the handles) and the jaw joint bolts (which keep the blades aligned).
All three joints act as pivots when the jaws are opened and shut, and this compound arrangement helps to magnify the force that the user applies to the handles of the tool much more than a single hinge would. The jaw joint bolts are subject to great strain from different directional forces as they allow the jaws to open while holding them flat.
Adjustment bolts
Most bolt cutters (except fixed-head compact types) have one or two adjustment bolts on the neck which can alter the angle of the blade they are closest to. Where tools have two bolts, both blades can be adjusted.
In addition, the bolts on the jaw plates can be turned to adjust the gap between the blades.
These are all “eccentric” bolts, which means they have an irregularly-shaped shank, similar to a cam. Turning the bolt moves one of the bolt cutter blades. Adjusting the jaws with either set of bolts can help to compensate for sharpening, or fine-tune your bolt cutters to allow them to fit around thicker pieces of material.
For more information on how this works, and on setting up your bolt cutters so the blades are the correct distance apart, see: How to adjust the jaws on bolt cutters.
Handles
Bolt cutter handles vary both in length and in the material they are made from. This makes a significant difference to their weight and usability. Longer lengths are helpful for cutting materials which are down low, up out of reach or require a large amount of force, while short pairs are lightweight and useful for thinner materials which are easily within range.
Handle stops
Regular long-handled bolt cutters often have a pair of metal protrusions (or “stops”) at the neck or a short way down the handles. These prevent the handles – and hence also the blades – moving too close together and overlapping at the end of a cut.
Handle grips
For extra comfort and tool control, most long-handled bolt cutters have grips at the end of the handles.