Davonport Difference: Mortise and Tenon Joints
Rebecca Silburn | 05 April 2016
At Davonport quality of build is of the utmost importance, and that’s why we use the best materials and methods when manufacturing your kitchen furniture. Whilst often it is the quality of wood and the finish that will be noticed first, the way in which it is put together is pivotal to a great kitchen cabinet and will ensure it stands the test of time.
In our new series, each month we will be looking at a technical element of cabinetry craftsmanship, to showcase the quality of our furniture interiors and describe why they make our kitchen cabinets stand out from the crowd.
This month our focus is: Mortise and Tenon Joints
What is a mortise and tenon joint?
A mortise and tenon joint is used most often to join two pieces of wood at 90 degrees, and consists of two parts; the mortise hole and the tenon tongue. On the surface it seems like a very simple join but is one of the strongest there is, and subsequently has been used by cabinetmakers and joiners for generations. All our doors are tenoned together and we sometimes tenon our cabinets together for extra strength. This joint requires expert craftsmanship due to the precision needed to ensure its strength. The mortise has to be exactly one third of the thickness of the wood, in order to avoid it splitting or the tenon breaking. The tenon then has to be cut to fit the mortise hole exactly and usually has ‘shoulders’ which sit flat against the mortise member when the tenon is fully inserted into the hole. Usually the tenon is also taller than it is wide, to ensure stability.
There are many different types of mortise and of tenon, suitable for slightly different applications;
- open mortise - only has three sides
- stub mortise - is a shallow mortise, dependent on the size of the timber
- through mortise - mortise that passes entirely through the wood, so you can see through it
- wedged half-dovetail - where the back is wider or taller than the front, or opening
- through-wedged half-dovetail - a wedged half-dovetail which passes entirely through the mortise piece
- stub tenon - a short tenon
- through tenon - a tenon that passes through the mortise, so it is visible on the back side
- loose tenon - a tenon that is a separate piece of wood, rather than cut out of one piece of timber
- pegged / pinned tenon - the joint is strengthened by driving a peg or dowel through one or more holes drilled through the side of the joint
- tusk tenon - uses a wedge-shaped key to hold the joint together
- teasel / teazel tenon - a specialised tenon usually on top of a post which supports a tie beam (a beam used to support roofing)
- top tenon - occurs at the top end of a post
- half shoulder tenon - an asymmetric tenon with a shoulder on one side only
Why do we use them?
As illustrated by the number of variations of both mortises and tenons above, it’s clear that this joint is one of the most versatile there is. They are also incredibly strong and well tested, meaning that they are also a highly efficient part of a build. In the same way that dovetail joints are favoured for drawer fronts due to their resistance to being pulled apart, mortise and tenon joints are usually used for frames. Thanks to their tensile strength, they are favoured for items such as windows, doors, beds and tables - typically where a sturdy frame is required and wood needs to be joined at 90 degrees. The mortise and tenon joint gives such a secure join in these circumstances that it is key to the longevity of the furniture. In fact the rigidity it gives to our kitchen furniture assists the lifetime guarantee we offer.