Ebony Screw Mortise Marking Gauge
Size: The head is 75mm wide and 24mm thick made from wood and brass. It has a brass rub strip to prevent wear and the locking knob is threaded through a brass pin to ensure it won't wear out. The arm length allows you to scribe one or two parallel lines 0 - 160 mm from the edge.
Average weight: 500 grams
Markers: Are 2 x HSS pins specially sharpened to a point. Maximum distance between pins is 53 mm.
Purpose: Marking out joints where one or two parallel lines are required, eg mortise and tenon joints. The screw action allows you to very accurately position the pins in very small and precise increments. The trade off here is setting the distance between the pins is slower than the slide action. Makes a very neat line with the grain and on end grain but leaves a ragged line across the grain.