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Mechanical screw machine

Fully threaded shank, usually used with a nut, usually smaller than a regular screw, designed to secure to an existing threaded hole

Mechanical screw

Mechanical screws, sometimes called mechanical bolts, are usually smaller than ordinary screws. Their size ranges are typically as high as 3/4 inch (19.05 mm), but they can still vary considerably. In general, machine screws are designed to be tightened into existing threaded holes on metal surfaces and are usually used with corresponding nuts. The main distinguishing features of mechanical screws are: overall size, head shape, groove type, length, material and thread type.

The two main drive types associated with machine screws are slotted (flat head) and Phillips. There are also a number of dedicated drives that can be accessed, often associated with tamper resistant screws. Some of these drive types include clubs – hexagonal heads, wrenches, tridents, etc. Once in place, the shape of the head determines the position of the machine screws. The round and pan heads will protrude from the plane, while the flat head machine screws are designed for countersunk holes so that they are flush with the surface.

The machine screw always runs through its entire length. Threads on machine screws are important because the corresponding holes to which they are fastened are usually tapped for specific sizes and types of threads. The two main characteristics of the thread are the size of the thread outer diameter and the pitch, and the distance between each thread. Mechanical screws can be threaded clockwise (right-hand) or counterclockwise (left-hand).

Sheet metal screw sheet

Fully threaded shank, widely used fastener, which can be used for metal, wood and plastic. Most of them are self tapping screws, requiring only one pre drilled hole, and some have self drilling tips

Specially hardened sharp thread, which can cut the material and form its own internal thread

Sheet metal screw

Sheet metal screws have full threaded shank with sharp threads and tips that enable them to cut metal, wood, plastic, and various other materials. The size of a sheet metal screw is usually displayed as a series of three numbers, which represent the diameter, number of threads, and length of the fastener. Listed as 4-32 x 1 -? " The diameter of the sheet metal screw of is 4, there are 32 threads per inch, and the length is 1 -? ".

There are two basic types of sheet metal screws, self tapping screws and self drilling screws. Self tapping screws have a sharp point designed to cut through metal, but the metal must be pre drilled before using these screws. The self drilling screw has a drill point, which can easily cut through the metal without pre drilling.

Sheet metal screw heads can come in many different styles. The head of pan head or round head screw will protrude from the material surface after installation. Flat or oval countersunk head screws shall be installed flush with the top of the material. These screws can be equipped with Phillips, flat head, or combined drives.

Sheet metal screws made of carbon steel are the most common and often the most economical. These screws are prone to rust and corrosion when exposed to moisture or chemicals, so they are usually used indoors only. Galvanized or stainless steel screws are designed to prevent rust and corrosion, but are often more expensive than standard steel screws. Sheet metal screws may be coated with zinc or nickel to change their appearance.

Capscrew Capscrew

Usually used without nut

Provide imperial and metric dimensions

Fastening machine parts - household appliances/consumer electronics

Large head, diameter greater than the threaded part


Capscrews have a large head and a cylindrical shaft with external threads. The diameter of the head is larger than the diameter of the threaded part, which provides a reliable mechanical stop when tightening the screws. Capscrews are screwed directly into threaded holes or tapped holes, usually without nuts. A large amount of clamping force is produced when the cap screws are tightened.

Common styles of cap screws include: hexagon head, hexagon head, and button head. Capscrews are usually made of carbon steel, stainless steel, and metal alloys. The type and size of capscrews selected for a particular application depends primarily on the force required to adequately secure the mechanical connection.
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