Fig. 266-35 Wedged mortise and tenon
No. 36. A fox-tail tenon is a blind mortise-and-tenon in which the mortise is made slightly wider at the bottom than the width of the tenon. Wedges are driven into saw kerfs in the tenon before inserting into the mortise; then when it is driven home the wedges spread out the tenon and make it fill out the mortise. It is used in strong doors and also where the mortised member is already in place so that a wedged mortise-and-tenon is impossible.
Fig. 266-36 Fox tail tenon
No. 37. A dovetail mortise-and-tenon is a thru mortise-and-tenon beveled on one side so as to form half a dovetail. The corresponding side of the mortise is also beveled and made wide enough so that when the tenon is pressed well up against its beveled side a wedge may be driven into the space left on the straight side. It is used to tenon a beam into a post especially where the post is fixed against a wall. It is also used in machinery frames which are made of wood.
Fig. 266-37 Dovetail mortise and tenon