Why use a haunched tenon

Clamp a guide block over the moulding to keep the chisel blade at the required angle. When a rabbeted frame is also moulded, it is necessary to mitre the moulding ends after the mortise and tenons have been cut. A possible alternative method is to scribe one end of the moulding to cover the other; the scribing is relatively difficult, but it is better for disguising gaps if the joint should shrink. Before marking out the joint, cut away the moulding down to the level of the rabbet, leaving a flat edge on the stile equal to the width of the tenon plus the haunch.

Similarly, trim the moulding off the rail, back to the shoulder line. Mitre the end of the rail moulding, then, using a gouge and straight chisel, pare away the wood on the inside of the mitre until it fits around the contour of the stile moulding. On the majority of tables, two rails are joined to a single leg at each corner. The joints are cut as previously described, except that the ends of the tenons are mitred where they meet inside the leg.

To make tapered chair frames, however, either the side-rail mortises must be cut at an angle , or the tenons are skewed to fit square- cut mortises.

A stronger joint results if you keep the tenons in line with the rails. Mark out each joint in the usual way, but mark the shoulders at an angle to fit the face of the leg.

You may find it easier to cut the mortise if you make a simple jig that holds the leg at the required angle, so that you can keep your chisel blade or drill vertical when cutting the joint.

Since it is easier to cut square mortises, it may be more convenient to skew the tenons. However, the inevitable short grain makes for relatively weak joints, so keep the angle to a minimum. It is impossible to mark skewed tenons with a mortise gauge, so use a sliding bevel and marking knife instead.

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Guide to Sanding and Refinishing Wood Floors. Related Category Hardwood. Simply put, Jim, a haunch—that extra bit of material atop a tenon—gives a tenoned rail more resistance to twisting. It also adds a bit of extra gluing surface, which never hurts. Any large project assembly, including paneled frames and doors, benefits from haunched tenons, as do frequently stressed joints, such as chair and table legs and rails. To appreciate the contributions of a haunch, it helps to compare a haunched mortise-and-tenon joint to similar joints.

For example, a typical mortise-and-tenon joint proves plenty strong for many applications. I don't think so much about gluing area The "added" haunch offers better resistance to twisting and greater surface area for getting the rails and styles in the same plane. And as people have mentioned, tenons have to be haunched on a table apron because they have to overlap inside the leg.

I've never been a fan of the mitered tenons meeting in the middle of the leg Sean, Thanks--I follow what you're saying.

My point was that over the length of a tenon, a full-height tenon would be stiffer or more rigid than a haunched tenon at the shallower section. Generally speaking, a 2x6 is obviously stronger, stiffer, more rigid, etc. Brett, I don't want to take on any mantle of authority here - we're just guys talking woodworking and trying to explain our thoughts to one another.

Anyway, I drew this quick sketch to explain my thoughts better perhaps. In the end, I think we are in agreement? Attached Images haunch talk. JPG Complete agreement, thanks for clarifying with the sketch! Now, you just need to post a video, similiar to your helpful bowl turning video, to show me how to create the angled, haunched tenon and mortise.

Is that the way you make them? Brett - A very slightly different take based on examining antiques. First, when the tenon is glued rigidly into the mortise, wood movement is restricted and becomes an issue. This can cause the rail to crack or the joint to fail.

Secondly, the long mortise can seriously weaken the rail. Spreading or splitting at the sides of the mortise is a possibility.

The solution is to divide the tenon into two sections. Two shorter mortises connected by a shallow groove will maintain the strength of the rail while separating the tenons allows a small amount of wood movement. Basically, it all comes down to matching up the structural requirements with the right type of mortise and tenon. The reward is a joint that will last a lifetime. Here are some supplies and tools we find essential in our everyday work around the shop.

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