[Fig. 3227] represents a cutter head for a tenoning machine, a, a and b, b being the cutters and c, c, d, d spurs which stand a little farther out than the cutter edges, so as to sever the fibre of the wood in advance of the cutter edges coming into action, and thus preserve a sharp shoulder to the tenon, and prevent the splitting out at the shoulder that would otherwise occur.
Fig. 3228.
To bring the outer edge of the shoulder in very close contact with the mortised timber, the cutters are for some work followed by what is termed a cope head, which is a head carrying two cutters bent forward as in [Fig. 3228], to make them cut very keenly, as is necessary in cutting the end grain of wood.
Fig. 3229.
The cope head undercuts the shoulder, as shown at a, a, in [Fig. 3229], which is a sectional view of a mortise and tenon.