Pocket Screw

Pocket-hole joinery, or pocket-screw joinery

involves drilling a hole at an angle, which is usually 15 degrees, into one work piece, and then joining it to a second work piece with a self-tapping screw.

A pocket hole jig is generally made of plastic and has a metal insert that the drill bit is inserted through to drill the hole. A jig can be a stationary device that the wooden pieces are clamped into, or a portable device that is clamped onto the wooden pieces

washer head or stop to prevent screwing too far into the joint and cracking the wood.

Be careful when you choose your screw !

What you can do with pocket screw?

Pros 

• Because the screws act as internal clamps holding the joint together, glue is unnecessary (but usually recommended) for most common joints. If glue is used, clamping is not required because of the ‘internal clamps’ holding the joint together while the glue dries.
• Gluing and screwing the joints together prevents gaps from forming as wood shrinks and expands with temperature and moisture.
• Requires only one hole to be drilled, eliminating the need to precisely line up mating workpieces, as is required with dowel and mortise and tenon joints.
• Does not require any complex mathematics or measurements, such as those used in mortise and tenon joints.
• Because pocket-hole joinery doesn't require access to the inside of the joint, quick repairs are possible without completely disassembling the joint. Fixing a squeaky chair or strengthening furniture requires only the drilling of additional pocket holes, and the use of screws to pull the two pieces together.
• Pocket hole joints have been proven to be superior to traditional joinery. A comparable mortise and tenon joint failed at 453 pounds under a shear load while a pocket hole joint failed at 707 pounds. ^[5]

Cons

• A broken pocket-hole joint "likely can’t be repaired".^[6]
• A bit expensive