The cutting heads of so called multicutter drill bits consist of a combination of several carbide cutters or of a single carbide head with several cutting edges. Because their geometry is more complex than those of the standard drill bits with a single cutting plate, they can not be checked according to general tolerances.
Mulitcutters have to proof during comparison tests that they are suitable for safe anchor installations.
This is done by pull-out tests with drop- in anchors in concrete with the multicutters and with standard drill bits. The pull-out forces in the boreholes of the multicutters shall be equal to the pull-out forces ion the boreholes of the standard drill bits. Only under this condition, the multicutter is approved by the PGM Steering Committee to be marked with the PGM seal.
The basis for the annual spot checks of multicutters are a dimensional table with additional tolerances for the angle between the cutting edges and the diameters and heights of the cutting edges, deposited at PGM, and an electronical gauge for the check of the head geometry.