Fig. 165.—Tenoning Moulded Sash Bar. Fig. 166.—Tenon with Tongued and Grooved Shoulder. Fig. 167.—Detail of Table Framing.

Tenon with Tongued and Grooved Shoulders ([Fig. 166]).—The object of the tongues and grooves here is to prevent the face of the work casting, or becoming warped, and thus spoiling the appearance of the surface of the work. If framing is to be veneered on the face side this is an exceptionally good method.

Table Framing.—[Fig. 167] indicates the framing of a rail to a dining-table leg. In cases similar to this the tenons run into the leg and almost touch each other. They are therefore mitred on the end as shown in the inset. Chair frames often call for similar treatment.

Twin Tenons with haunch, as used when the timber is of great thickness, are shown in [Fig. 168].

An Open Slot Mortise at the end of a right-angled frame is seen in [Fig. 169]. [Fig. 170] shows an open slot mortise and tenon joint at the end of a frame of 60°. Both these joints are occasionally called end bridle joints.

Fig. 168.—Twin Tenons for Thick Timber. Fig. 169.—The Open-slot Mortise Joint.

Hammer Head Tenons.—At [Fig. 171] is shown the method of jointing framing having semicircular or segmental heads. The left-hand diagram indicates the method of wedging the joint so as to draw up the shoulders; the right-hand view shows the tongueing of the shoulders, which is necessary if thick timber has to be wrought. The sketch depicts the stile when taken apart from the shaped head of the frame.

Clamping.—[Fig. 172] shows the method of tenoning drawing boards, desk tops and secretaire falls. This is commonly called clamping. The method is used to prevent wide surfaces from winding. A variation of the joint is shown at the left-hand side, the corners in this example not being mitred. [Fig. 173] shows the tenoning of a wide to a narrow rail when the joint is at an angle.

Inserted Tenons ([Fig. 174]).—Where two pieces of timber run together at an acute angle it becomes necessary to use inserted tenons. Both pieces of the timber are mortised and the inserted tenons are secured into the widest piece. On the left is shown the inserted tenon, secured by the method known as fox-wedging; on the right the inserted tenon has been let into the wide rail from the edge. The narrow rail is secured by wedging the tenons from the outside edge in the ordinary manner.

Fig. 170.—Open-Slot Mortise at 60 degrees. Fig. 171.—Hammer-Head Tenon Joint.