There are two main problems with a typical marking gauge: you have to tilt it just right to avoid pin chatter and, even then, the pin tends to follow the wood grain, throwing off your line. Wheel marking gauges solve both problems.
The hardened steel wheel cutter scribes perfectly at any point of its circumference. Since it cuts wood fibres rather than tears, it marks cleanly, even on cross grain. The wheel's single-sided bevel also pulls the gauge face against the stock, maintaining accuracy. Its cutting edge is at the extreme end of the rod, useful for transferring dimensions such as tenon shoulder and mortise depth. The wheel retracts into the face of the gauge for storage and protection. The gauges are very easy to set, since each has an internal O-ring to keep light but constant friction on the rod.
Due to the number of requests for a micro-adjust feature, Veritas developed a second model with a slightly longer body fitted with a two-stage collet to allow fine adjustment of the cutting wheel. The collet has a fine-pitch thread; one revolution advances or retracts the wheel 1/32in (0.8mm), a half turn 1/64in (0.4mm), a quarter turn 1/128in (0.2mm), etc. The knurled thumbscrew then locks the setting.
Mortice Gauge Head
Though designed for use with the Veritas wheel marking gauges, these gauge heads are a simple retrofit for any marking gauge with a 5/16in (7.9mm) diameter shaft – including the WMG-01 Wheel Marking Gauge.
Made from carbon steel, the 15.9mm diameter wheel cutters will scribe at any point in their circumference and slice rather than tear fibers for clean, accurate cuts. The single-bevel cutters are usable in-line for marking parallel lines, or with bevels facing for sure mortise sizing and chisel registration. Secured with integral set screws, the blades can be set as close as 9.5mm apart. The included shaft collar registers against the marking gauge fence to ensure the shaft remains parallel to the work piece, preventing accidental tilting of the cutters in use; this is especially useful when scribing large offsets from the fence.
Supplied as a pair of cutters with a shaft collar, hex key and instructions.