What is a stepped ratchet radiator key?
The parts of a stepped ratchet key are:
A stepped ratchet radiator key, also known as a plumber's step wrench, is useful for fitting valve tails where space is restricted. It can be set to clockwise (for screwing in) or anti-clockwise (for removing) radiator valve tails.
'Stepped' means that the key has fittings from small to large, stepped along the length of the key, for different internal hexagon and internal lug valve sizes.
The ratchet action means the handle will turn the key in only one direction - clockwise or anti-clockwise - according to the way it has been set by a small switch. Turning in the opposite direction does not move the key.
This is one of the two grooves in the stepped ratchet key which are used to turn internally lugged radiator valve tails.
This key also fits valve tails with internal hexagons from 3/8 inch up to 1 inch, including the most common 1/2 inch size.
In a restricted space where only part-turns are possible, the tail is secured or released with quick, repeated clockwise and anti-clockwise movements, with no need to reposition the key.
Stepped ratchet keys are usually made of hardened steel - often high tensile - for greater strength.
Some are made of chromium-vanadium steel. This is a steel alloy incorporating carbon, manganese, phosphorus, sulphur, silicon, chromium, and vanadium. This makes the steel harder, and the chromium provides resistance to abrasion and corrosion.
Seefor a step-by-step guide to these operations.