self-tapping screw is a screw that can tap its own hole when pushed to the material.
Video Self-tapping screw
Mekanisme
Self-tapping screws have a variety of tips and yarn patterns, and are available with almost any possible screw head design. A common feature is a screw thread that covers the entire length of the screw from tip to head and the thread is spoken loudly enough for the intended substrate, often hardened.
For hard substrates such as metal or hard plastic, self-tapping ability is often made by cutting a gap in the continuity of the yarn on the screw, producing a flute and cutting edge similar to those in the tap. Thus, whereas ordinary machine screws can not tap their own holes on metal substrates, a self-tapping can (within reasonable limits of substrate hardness and depth).
For softer substrates such as wood or soft plastics, self-tapping ability can come only from the smaller end to the gimlet point (where no flutes are required). Like the tip of a nail or gimlet, such a point forms a hole by moving the material around it rather than the drilling/evacuation action that forms the chip.
Not all self-tapping screws have sharp edges. The edges of type B are dull and are intended for use with pilot holes, often in sheet material. The lack of sharp edges is very helpful for packaging and handling and in some applications it can help to reduce the required permission on the opposite of the tied panel or to make more threads available on the given long screw.
Maps Self-tapping screw
Self-drilling screw
Some self-tapping screws are also self-drilling , which means that, in addition to the tap-shaped flutes on the main thread, there are also flute tips like the initial drill that looks like a central drill tip. These screws integrate the thrilling action and the mounting of the fastener itself into just one driving motion (not separate drilling, tapping, and mounting motion); they are thus highly efficient in a variety of hard-substrate applications, from assembly line to roof.
Metal sheet screw
The sheet metal screws (sometimes called "metal-sheet shears", or screw PK from the Parker Kalon brand name - pioneered the creation, but did not create, this screw) is a type of self-tapping screws although the threads made in sheet metal become small. Self-tapping PK self-tapping screw Pan-head is commonly used in electrical equipment, while flat-headed truss or self-tapping flat stitching screws are more commonly used in flight applications.
Self-winged tapper
Winged self-drilling has a wider wing that is wider than the thread that formed just behind the drilling head itself. It cuts permit holes in soft materials (such as wood or plastic), but is destroyed by stronger materials (such as metals). Thus, to clamp some materials into metal, drilling drilling, tap drilling, tapping yarn, and mounting itself may occur in one operation from one side, with the material in their final position.
Apps
Self-tapping screws are used in a variety of applications ranging from DIY carpentry to surgery. Many dental implants and orthopedic bone screws are examples of self-tapping screws used in operations.
Thread-forming vs. Cutting
Self-tapping screw can be divided into two classes; ingredients that substitute (especially plastic sheets and thin metal) without removing it are called screw tapping screws themselves; self-tappers with sharp cutting surfaces that remove inserted material are called self-cutting .
See also
- Fasteners with sharp shanks
- Tap
- Pentalobular screws
References
External links
- "Hold Everything", February 1946, Popular Science at the bottom of page 151
Source of the article : Wikipedia
0 Comments