The S-shaped bend, otherwise described as the ‘crank’, is a key design feature of traditional jointers.
The bend helps the user to control the angle of approach and the amount of compression that is applied to the joint.
End (radius) profile
The end profile of the jointer determines the type of imprint that will be left in the mortar. It may also be referred to as a radius because of its curvature.
Jointers have consecutive size radii at either end of the tool. Their measurements are commonly stated on the mid-section of the tool.
Tool mid-section
The mid-section is where the tool should be gripped during use. It is also where inscribed measurements can be found, often in a central location. These measurements refer respectively to the size of the radius at either end.