Jointing technology describes a process where the blades of the cutting knifes are brought to an even outer diameter or where they are honed and grinded within the machine by leading to a jointing stone. Condition for it is that the tools themselves are already very good round-cut and that the tool clamping system has very low concentricity tolerances.

The Weinig company introduced this system in around 1975 as standard for moulders.

Description of the process

In the process of jointing the jointing stone is applied radially step-by-step up to the point where it touches all cutters so that all the cutters get jointed. After that approximately 0,015 up to 0,02mm are applied radially in each jointing process. When the maximum joint chamfer width is achieved, the tools with the clamped cutting knifes are removed from the machine and the cutting knifes are regrinded in a grinding machine.

Jointing means to grind the cutting knife´s blades radially means to grind them with a clearance angle of 0°. Because of a decreasing processing quality at a depressing blade this is only possible up to a certain extent. De facto so called joint chamfer widths of maximum about 0,7 mm are approved. To achieve this maximum joint chamfer width with as many jointing processes as possible it is necessary to create the before-mentioned prerequisites. Otherwise the first jointing process at which the blades of all cutting knifes of the tool shall be brought to an even outer diameter already uses the biggest part of the possible joint chamfer width.

Straight and profile jointing

A basic distinction is made between straight jointing and profile jointing. At straight jointing - for straight, non-profiled planing knifes - a jointing stone in the form of a pin is radially applied and the process happens axially parallel so that the planing knifes´blades can be jointed to their full length. Disadvantage of this procedure is that the relatively small jointing stone wears off very fast which causes - in an extreme case - a conically tapering cutting knife as a result of the jointing process.

Profile jointing happens with a jointing stone having the counter profile of the cutting knife´s blade; it is only radially applied.