Page:Cassells' Carpentry and Joinery.djvu/85

Rh Housing.—The simple housing joint is shown by Fig. 301.

Tenon Joints (Joiners').—Some tenon joints have already been shown under the heading, "Joints in Carpentry" (p. 55). Further tenon joints, more especially used in joinery, are: the simple open tenon and mortise (Fig. 302); closed mortise and tenon (Fig. 303); pair of single tenons, commonly called "double" tenons (Fig. 304); double or twin tenons (Fig. 305); pair of single tenons, with grooves and slip feathers (Fig. 306); haunched tenon (Fig. 307); dovetail tenon (Fig.. 308); pinned tenon (Fig. 309). Stump or stub tenons and tusk tenons are also used in joinery, and have already been illustrated (Figs. 195

and 200, pp. 55 and 56). The foxtail tenon (Fig. 30) is a good joint; alternative methods (with and without housing) of applying this in fitting rails into an oak gate-post are shown by Fig. 311.

Proportioning Tenons.—There is no universal rule for proportioning tenons, but the practice is to give from half to the whole of the width of the rail, when this does not exceed 5 in., for the width of the tenons. If more space than half were given to a haunched tenon, the end of the stile would be liable to be driven out in wedging up, and there is no reason why more space should be given. Wide tenons are objectionable, owing to their liability to shrink from the wedges or the sides of the mortises.

Applications of Tenon Joints.—With regard to the application of the various tenon joints, a few of these are noted below: A simple tenon, one-third thickness of the stuff, is used in framing together pieces of the same size, the mortise being just long enough to allow of a wedge being driven in on each side of the tenon to secure it. A pair of single tenons, usually called a double tenon, is used for connecting the middle rail of a door to the stiles. A haunched tenon for connecting the top rail of a door to the stiles; the tenon being half the width of the top rail leaves a haunch or haunching to prevent the rail from twisting. A stump or stub tenon is used at the foot of a post to prevent movement. A tusk tenon is used in framing trimmers to trimming joists, to

obtain the maximum support with the minimum reduction of strength. A tenon with only one shoulder is used in framed and braced batten doors, and in skylights, when the rail requires to be kept thin for other parts to pass over; this is known as a barefaced tenon. A pair of double tenons is used for the lock rail of a thick door, to receive a mortise lock.

Hammer-headed Key Joint.—A conventional view of a hammer-headed key joint apart is presented by Fig. 312.

Special Joints.—Many other joints adapted to particular purposes are described in subsequent sections. Reference to these may easily be found by consulting the index.