These two flute cutters are similar to the corner lock type A, but have a double lock joint. This gives a proportionally longer glue line than a single lock joint and ensures a stronger joint at the expense of a more complicated machining operation. These cutters are suitable for the rapid construction of drawers, boxes etc.
The cutter must be used in a table mounted router with a tall fence fitted. To produce a drawer joint, simply cut the drawer front flat down on the table with the outside facing upwards. Cut the drawer side vertically with the inside facing the fence. The minimum stock thickness for the front is 19mm and for the sides 10mm.