Wrenches - Adjustable
As the name implies, it is possible with one tool to adjust the jaws to suit various sizes of bolt and nut head. This is particularly useful when only a limited number of tools can be carried in a tool kit on site.
Care must be taken when using adjustable wrenches to ensure that the sliding jaw is always tight up against the nut or bolt as it is possible for them to loosen in constant use when they can slip and damage the nut or bolt head. A test for a good adjustable wrench is that the sliding jaw when open should be firmly held in the channel and have no movement from side to side.
The size of an adjustable wrench is usually expressed as the overall length of the tool and not the jaw capacity. However, jaw design greatly affects the capacity and a well designed wrench may have a considerably better capacity than other brands of the same length. Ergonomics has also been introduced to a range of these tools for more efficient use and better application.
Wrenches - Leader
Leader wrenches are designed so that the housing for the hook jaw and the adjusting nut is an integral part of the handle. They have a one-piece ductile iron casting of great strength.
Designed for heavier-duty work and heavy civil engineering and oil fields. Because of the design, the leader wrench has a higher jaw capacity than an ordinary stillson wrench of the equivalent length.
Wrenches - Hexagon
Used for driving socket screws. They are frequently described as Allen keys (and Allen screws) but as Allen is the brand name of Holo-Krome, based in the UK and USA, the word Allen should only be used for genuine Allen products.
Wrenches - Pipe
These have V grooved teeth for gripping smooth round pipes. They should not be used on nuts, bolts and hexagonal fittings, or non-ferrous tubes and pipes where they could cause damage.
Wrenches - Stillson
These have four main components, the quality of all of which is important:
It is designed so that when pressure is applied all the stress is transmitted through the steel hook jaw and steel adjusting nut to the handle abutment.
This provides maximum strength and leverage.
Beware of cheap quality or imitation products.