Woodworking joints – Angle joints (Part 3)

The Tusk Tenon

Another type of mortice and tenon joint used is the Tusk tenon. Arranged to weaken the timbers as little as possible, the tusk tenon is used in floor and roof construction. The tenon – which usually has a thickness of one-sixth the width of the material – is strengthened by projections left on the shoulder. The tenon projects through the timber that it is being jointed to and is secured with a wedge or key. A vertical section and plan are shown below (Fig A), and an isometric view (Fig. B). The tusk tenon, although not used as commonly as it once was (due to the likes of joist hangers), can still be found in floor joists.

  1. The wedge or key
  2. The tenon
  3. The tusk

tusk tenon jointWoodworking joints - The box tenon

Box tenon

Sometimes used for corner posts in lantern light windows, the Box tenon (Fig. C) is more complex to make than it looks. The easiest way of cutting the tenon is to cut using a tenon saw, giving, infact, three separate tenons.

Tease tenon

The Tease tenon (Fig. D) is used when two rails are at right angles to each other in a corner post Z. The tenon on the piece X has the top part removed, whilst the piece marked Y has part of the bottom removed. The tenons pass over each other and may be also be wedged. When it is required that the tenons shall not be seen from the outside, then the tenons are kept to the full width and mitred at the ends.

Woodworking joints - the tease tenonWoodworking joints - Chase mortice

Chase mortice

A Chase mortice (Fig. E) is an ordinary mortice for a stub tenon, but the mortice is continued with a chase so that the rail can be swung round into the mortice. It is used for placing intermediate members into position after the framing has already been fixed. One end of the timber is fixed into postion using a normal stub tenon and then the other end is slid into position along the chase.

The Bridle joint

The Bridle joint is basically the reverse of the mortice and tenon joint. In bridle joints, the middle part of one piece of timber is cut out so it will fork on to the other timber, which is cut to receive it.The two pictures below show bridle joints for when the two timbers are at right angles to each other (Fig. E) and also the type of bridle joint that could be used in roofing work where the two timbers meet at an angle.(Fig. F).

Bridle joint

Notched and cogged joints

Notched joints are similar to halving joints, except that the faces of the two pieces are not flush. A straight forward notched joint is shown below (Fig. G), whilst a notched joint that prevents the movement of both pieces (Fig H) is also shown. A Cogged joint (Fig.I) is an extension of both the notched joints shown and is prevents movement of both timbers.

Notched woodworking jointsBirdsmouth joint

Bird’s mouth

The Bird’s mouth joint (Fig. J) is used for timbers that are not in the same plane. A common example can be found in a traditional cut roof, between the foot of the common rafter and the wall plate.

This finishes our look at angle joints; our next post will be looking at joints for joining timber in length.

For quality workmanship by time-served Joiners:

Call Jon & The Team on 01745 362444

or email a question to enquiries@woodworkersuk.co.uk

Comments

  1. Paul Matthews says:

    RE: 2 and 3D CAD Drawings of a Mortise and Tenon joint

    I am a CAD student. I am looking for drawing of a Mortise and Tenon joint.

    I have searched on ‘Google’ for the drawings without any success. I would be very grateful if you could help me in this matter and tell me where I might source these images.

    I look forward to hearing from you.
    Thank you
    Paul

  2. Hello, thanks for a very informative page. About the Tusk Tenon – I always thought tusk tenon and keyed tenon meant the same thing – but your drawing says the tusk is below the keyed tenon. Do you have a source for info on this, I would like to know more about it! Thanks.

  3. The key (or wedge) is used to secure the tenon and stop the tenon from coming apart, most commonly it’s called a tusk tenon but sometimes it is as you mention called a keyed tenon.

    Hope that helps!

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