Types-of-Wood-Joints.pptx

Module ppt

1. Types of Wood Joints

2. What is a wood joint ?  A joint is a natural connection where the ends of two wooden workpieces meet. It's designed to hold the wooden workpieces together, thus eliminating the need for glue or adhesives.

3. Common Types of Wood Joints.

4. Butt Joint The end of a timber board is called the “butt.” Woodworkers forming this joint are placing two ends together at a right angle to create a corner. Mechanical fasteners such as nails or screws are necessary to preserve this joinery. You see this technique used most often when building wall or attic framing. Some picture frames, decking, and sandboxes also use it.

5. Mitered Butt Joint (Miter Joint) This joinery option connects two butts that get cut at an angle. The advantage of using this approach involves the strength of the corner. You receive a seamless look that does not show any end grain. Uses:  Since the miter joint has minimal strength, it is typically used for trim and molding purposes. Depending on the purpose, you may need to strengthen the miter joint by adding nails. A classic example of mitered butt joinery is the wooden picture frames.

6. Half-Lap Joint Woodworkers use this joint to join two boards together to create a flush surface. It happens most often when a connection is needed in the middle of the timber, although corner connections are also possible.

7. Cross-Lap Joinery If the wood joint forms in the middle of both boards, it is called a cross lap joint instead. You see this woodworking joint used for framing and cabinetry quite often. A bird's mouth joint is a common variation used when the connection must be at an angle.

8. Tongue and Groove Joint Carpenters join two flat boards together to create a larger wooden panel using this option. One has a long edge carved at the edge, while the other has a groove cut in to receive the board extension. It can stay secure glue or fasteners for flooring, furniture, and similar applications.

9. Dado Joints The dado joinery method is similar to a tongue and groove joint. The only difference is that the dado is cut across the woodgrain whereas a groove is cut in the grain direction which is usually along the length of the board. Moreover, there is no tongue carved on the edges, instead, the groove is cut wider to accept the thickness of the mating piece. Furniture makers and woodworkers typically use it for  plywood , fiberboard, or other pressed products. Builder’s grade cabinets often use this technique to create a resilient product.

10.   Biscuit Joint Woodworkers use this technique to create a more robust version of the butt joint using tongue and groove principles. Both ends of the timber get a slot cut into them to hold a small wafer that acts as a connection. When the glue gets added to the insert, it starts swelling until the entire carved-out area gets filled. Most tabletops and wooden counters use the biscuit joinery method to create a more reliable joint suitable for daily use. 

11. Mortise and Tenon Joint This woodworking joint was one of the first methods invented for construction. Mortise and Tenon joinery continues to be one of the strongest wood joints to use for framing and building. It requires precise measuring and craftsmanship to complete. The joint typically requires a 90-degree connection to be useful. Uses:  This type of wood joint is often used in furniture making and crafts. Your table legs are most probably joined by a stopped mortise and tenon joint and the chair legs are often attached with the help of angle mortise.

12. Rabbet Joint Woodworkers form this joint by forming a recess into the edge of the timber. It looks like the protruding edge from a tongue and groove joint, except it only has one side cut from it instead of two. While the rabbet joinery is a simple wood joint, it is much stronger than the butt joint. This technique allows a flat piece, such as the back of a cabinet, to sit flush with both sides for a seamless finish. You also see this joint used in doors 

13. Dovetail Joint Woodworkers use this option to add strength to a corner. It uses interlock joinery of a series of pins and tails to create a resilient edge that can be used for furniture, cabinetry, and framing.

14. Half-Blind Dovetail Most drawers use this joint design because it features a trapezoid design for the pins that fit together at the end of the timber. Woodworkers use it to avoid having the connection visible from the front of the piece without compromising their work’s strength.

15. Sliding Dovetail Joint Yet another variation of dovetail joinery is the sliding dovetail joint, which works like a tongue and groove while using the dovetail technique. As you can see in the image, here the dovetail slot is machined in the face of the board while the pin profile is cut at the end of the matching piece.

16. Box Joint This joint works at the end of two timber pieces to build a seamless right angle. You carve out a series of symmetrical slots to form rectangular projections called fingers. Once you glue the connection, the fingers get inserted to create a permanent bond that results in a solid corner. Box joinery is an effective alternative to dovetail joints. The dovetail joinery works best on hardwood and it requires a complex machining process. On the other hand, box joinery is easy to create and works on most types of wood including plywood. You can easily cut the fingers of the box joint on a table saw with a set of dado blades.

17. Bridle Joint This approach uses a modified version of the mortise and tenon joint. Instead of cutting a square piece to form a corner, woodworkers create a lengthy edge that fits into a grooved receptacle. It creates a right angle through this connection with three adequate surfaces that hold adhesive for added strength. When you add rails to the modern bed frame with a headboard and footboard, the most common connection is a bridle joint. You can find several variations of this technique including t-bridle, mitered bridle, and double bridle joints which is commonly used in canvas stretcher bars.

18. Finger Joints This type of wood joinery technique is mainly used to join two pieces of wood to make a longer board. A lengthening joint usually has a larger gluing surface between the joined pieces. First, you have to cut fingers similar to a box joint, but deeper. In the case of a box joint, you join two pieces of wood at 90 degrees to achieve a solid corner. Here you lay the mating wood pieces flat and assemble them with a thin layer of wood glue between the fingers.