Why should I use special screws? Here we will find the answers to all the questions we are looking for in a little while. Specially shaped parts are used to connect two or more parts, then disassemble them without destroying them. These are also called special screws. Also screw, on the other hand, is the connecting piece that connects the parts in a detachable way without using a nut. The part of the bolt or screw that is partially or completely threaded is called a screw. In order for these special screws to work properly, special profiled threads have been drilled on their barrel-type cylinder. Why should I use special screws? Special screws have many advantages in our lives. Special screws are used in almost every aspect of daily life. It takes more time and less power to drive a nail into the same material than driving a screw. For builders who use hand tools, these special screws can make a construction project much easier when included. In power tools, the screws require less power and the motor of the electronic tool is less strained.Also , ccrews can be removed and screwed many times.Moreover, they are very easy to obtain as they are fully standardized.Furthermore, they are easy and inexpensive to manufacture.In additon , they are very easy to replace. Now we understand better why we should use special screws.
Usage Areas of Special Screws
· In the gear housing with pinion
· In the mounting of machines
· For connecting pipe flanges, cylinder' gate
· In steel constructions
· Where pre-tensioning is required (tension bolt)
· Closing the oil holes (plugs)
· Where wear and overcenter preload is required (adjustment bolt)
· In measurement processes (such as micrometer, etc.)
· Where large prestress is required with small environmental force
· (vice, screw press, jack etc.)
· Where rotational movement is desired to be converted into progress
Screws According To The Purpose Of Use
1. Metal Screws: Triangular, square, trapezoidal, round and special profile screws are all considered in this group.
2. Sheet Screws: They are used in bolts that are used to connect sheet metal and thin-walled materials to each other in a dissolvable way.
3. Wood Screws: It is used in bolts that are used to connect wooden parts in a loose way.
4. Special Screws (Pipe screws): These screws are a special form of whitwort screw. The pitch of the pipe screw is smaller than the normal whitwort screw, so its threads are tight. In addition, the external thread of the pipe is made conical in the ratio of 1:16. This taper pipe ensures tightness when screwing the pipes.
5.Screws by Number of Screw Head: The number of screw head can be seen when looking at the screw from the forehead. According to the number of screw head, it is classified as one-head, two-head or multi-head screw thread.
Screws According to Thread Profiles
When viewed with respect to the screw axis, the shape of the threads represents the thread profile. Thread can be made in various profiles.
1. Triangular screws: They are isosceles or equilateral triangle profile screws with a apex angle of 55°-60°. It is used in screws for connection purposes. Squared head and triangular screws can also be used while winding spring on the lathe. These screws can be made according to the metric or inch system. According to the metric system; Equilateral triangle profile, apex angle is 60°. The symbol for metric triangular screws isshown by “M”. In short representations, the symbol "M" is placed before the basic size, and the standard number is written after the basic size.
2. Trapezoidal screws: They are screws with a trapezoidal profile, symmetrical role of cross-slip of screw , with wide screw thread tops and bottoms (not pointed). Trapezoidal screws are used as movement screws in presses, jacks, valves, table and console shafts of turning and milling machines, on lathes when making turned parts. The symbol of the trapezoidal screw is expressed with “Tr”. It is used in places such as workbench table, screw press, vice shaft etc. to transmit motion.
3. Saw Tooth Screws: Threaf profiles are screws similar to saw teeth, which are generally used in unidirectional force and motion transmission. The thread profile angle is made unidirectional and the thread bottoms of the external screw are rounded. It is expressed with the symbol "Te" in short notations. After the symbol, the nominal diameter, screw pitch and standard number of the screw are written.
4. Rounded Head Screws: It is a rounded head screw on the bottom and top of the thread. Since the thread profiles are round, the friction surfaces are less. Water valves, hose connectors, cap screws of plastic and glassware, etc. used in places. The rounded head screw is indicated by the symbol "Yv".
5. Squared Head Screws: It is the squared head screw profile with thread filling and backlash. It is used a lot because it is easy to make compared to other screws. It is made according to metric and inch dimensions. Squared head screw can be opened at the desired step, to meet the need on the desired diameter. There is no standard. Its symbol is “Kr”.
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