Ads
related to: 12mm self tapping screws
Search results
Results From The WOW.Com Content Network
A self-tapping screw is a screw that can tap its own hole as it is driven into the material. More narrowly, self-tapping is used only to describe a specific type of thread-cutting screw intended to produce a thread in relatively soft material or sheet materials, excluding wood screws .
self-tapping machine screw: A self-tapping machine screw is similar to a machine screw, except the lower part of the shank is designed to cut threads as the screw is driven into an untapped hole. The advantage of this screw type over a self-drilling screw is that, if the screw is reinstalled, new threads are not cut as the screw is driven. set bolt
Example (inch, coarse): For size 7 ⁄ 16 (this is the diameter of the intended screw in fraction form)-14 (this is the number of threads per inch; 14 is considered coarse), 0.437 in × 0.85 = 0.371 in. Therefore, a size 7 ⁄ 16 screw (7 ⁄ 16 ≈ 0.437) with 14 threads per inch (coarse) needs a tap drill with a diameter of about 0.371 inches.
Two screws in the stock bear in to indentations on either side of the slit, tending to squeeze the slit closed, whilst a third screw with a tapered tip screws in to the slit forcing it open. Working these three screws against each other adjusts the die. Integrated screws appear to be common in the US but are almost unknown in the UK and Europe.
Self-tapping pocket screws are used for pocket hole joints. Pocket screws are generally more expensive, but they are needed for a tight, strong joint. Pocket screws have a wide washer head to spread the load for a firm bond, and prevent screwing too far into the joint and cracking the wood.
The Phillips/square screw drive, also known as the Quadrex, Pozisquare screw drive, is a combination of the Phillips and Robertson screw drives. While a standard Phillips or Robertson tool can be used, there is also a dedicated tool for it that increases the surface area between the tool and the fastener so it can handle more torque.
Ad
related to: 12mm self tapping screws