What is a Haunched and Relished Mortice and Tenon Sash Joint?

This is a haunched and relished mortise and tenon joint. The haunch is the removed portion of the tenon which allows it to pass into the four sided mortise (as opposed to three in an open or slot mortise). The relish is the drilled away portion that allows the joint to close at the high part of the sticking. In show and tell work, this can be cut away with a hollow chisel machine for a cleaner look. Most window sash was traditionally drilled with a relishing bit.

There were single purpose machines made specifically to perform these to functions. A few remain but they are not common. For small runs, the band saw and drill press suffice.

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This shows the relish pretty well.

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This shows the haunch. This is a top rail to stile sash joint in Douglas Fir.

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Joints assembled. These are Western Red Cedar storm sash. The edges are rabbeted to fit into the blind stop in double hung jambs.

This is a hauncher/relisher. I recently brought this machine in from the lean to where I have had it for and embarrassing number of years waiting to be restored. It is a mortiser also on the the other end.

The rails are placed in the sliding table an pushed into the drill (relish) and the cutter (haunch). The cutter has skewed knives.  The little platen supports the tenon at the shear. The relish works in advance of the shear. Some haunching heads have spurs. Not this one.

This is the haunching head. A little worse for wear. For some reason, some operator found it necessary to hammer on this a lot. Those are the knives. Similar to tenoner knives.

This step in window making is absent in cheaper work.

This is the relisher and hauncher at work. The guard is off so you can see what’s going on. It works real fast. But I have some tuning to do. For one thing, the relishing bit is secured from a set screw and the bore is wore on account of that. the haunching head has had it’s spurs removed. It works without but i want to experiment. The heads are cast but not machined under the knives. So it’s a real good thing these are carbon steel knives.

It seems this machine was loathed by it’s operator. Much abuse. Much hammering. I am surprised by the quickness of the milling.

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