Types of screwdrivers

The screwdriver has been used as a tool since ancient times. And even today it is impossible to imagine an industry and economy where this simple but useful locksmith tool is not used in typical situations.

The screwdriver belongs to manual locksmith tools and is used for unscrewing and screwing fasteners, mainly threaded, and equipped with a slot. That is, mainly — for working with screws and screws.

The main parts of a screwdriver are — it is a metal rod with a tip and a handle, a handle that can be plastic, wooden or metal with rubber pads... Thus, in its simplest form, a screwdriver is simply a metal rod fitted with a bit to securely fix the tool in the socket, as well as a handle that is comfortable to hold in the hand when using this simple tool and that does not slip at the same time. Most self-respecting men always have at least one screwdriver in their household, or a pretty serious set of them.

The handle of a typical screwdriver is 10 to 40 mm in diameter, depending on the size of the screwdriver itself and the specifics of its reach.The larger the diameter of the handle, the more torque can be transmitted to the spline, so the wider the spline, the wider the handle, as a rule. For working with small parts, small screwdrivers are designed, with small narrow handles, so as not to accidentally tear off the slot or thread.

Large screwdrivers are used to work with large screws and screws, and sometimes, in addition to just a thick handle, they have a special hole on it, where an additional rod is inserted, which serves as a lever and allows you to increase the torque.

As for the tips, for high-quality screwdrivers they are made of special wear-resistant alloys, for example, molybdenum steels or chrome-vanadium. This is necessary so that significant mechanical stresses do not make the tool unusable before time, that is, to extend the life of the screwdriver.

Depending on the type of slot on the screw head or screw, screwdrivers are equipped with different types of tips, mainly straight (slotted) or cross-shaped are the two most popular types of tips on the most common screwdrivers used at any time. There are other types of tips and we will talk about them later.

Straight slot — the simplest, historically it was the first type of slot for a screwdriver and has been used since the 16th century.

The next type of tip is cross-shaped, it was invented in 1933 by the American John Thompson, who proposed such screws to fix the tip of the screwdriver in the center of the head and push it out when the screw is tightened.Today, this type of bit is called "Phillips" because Henry Phillips, the enterprising engineer who founded the Phillips Screw Company, promptly bought out Thompson's patent and introduced Phillips screw and screwdriver technology to Cadillacs in 1937, and later during World War II. screws began to be used in the creation of military equipment.

Slot with cross "Pozidriv"... This is an improved Phillips tip, which was patented by the same company Phillips Screw Company in 1966. Unlike the first option, this slot is not self-tapping, has a large seating depth, is used with screws with large heads and when working with self-tapping screws.

In addition to the standard Phillips bit, it adds sharp beams on the edges to further secure the fastener and allow even more torque to be transmitted. Thanks to Pozidriv slots, furniture production, construction and many others began to have more reliable fasteners.

Hexagon slot… Allows you to further increase the torque. This type of tip was developed in 1936 by the German company «Innensechskantschraube Bauer & Schaurte». Another name for such a tip is «INBUS», in everyday life it is «inbus key». The head of the fastener is in the shape of a hexagon, and the force is up to 10 times greater than with a cruciform solution. In addition, the screwdriver does not slip out of the recess.

Torx slot… This is a hex star spline. The use of screws for this type of tips is widespread in the manufacture of various electronic equipment, household appliances, as well as in mechanical engineering. This type of tip was developed in 1967.from Textron to tighten fasteners with increased strength and significant torque.

Today, there are also special bits used for screws and special purpose screws. For example, it may require enormous clamping force with a small head size or simply an aesthetically pleasing appearance. Special types of advice and will be discussed further.

Tri-Wing Tri-Wing Slot… It was patented in 1958 by the Phillips Screw Company when a spline was needed for assembling wide-body aircraft that did not require axial pressure during tightening. Today, such screwdrivers are freely sold, and screws with a Tri-Wing head are used, for example, in chargers of the NOKIA brand with protection against disassembly.

Asymmetric Cross Torq-Set… It is included in Tri-Wing, same company. Screws with this type of slot are used only in the aviation industry, but screwdrivers for it are freely sold today.

One-way slots found on screws in public places where vandalism is thus prevented. The socket is one-sided, and the screwdriver tip only allows screwing, screwing and tightening. It will be impossible to unscrew the element with a screwdriver; you will have to weld the key or drill a more convenient slot for a simpler, more convenient screwdriver.

Two-pin tip (wrench) These are used where aesthetics and protection against vandalism are important, for example in civilian elevators. Along with these types of bits and splines, there are also slotted flat bits. The functional purpose is the same. Often, screws for such screwdrivers are used in household appliances that do not allow the intervention of amateurs.

Socket Torx bit for Torx slot with pin… Unlike conventional Torx, this slot has a hole in the center.

Of course, regardless of the type of tip, regardless of the type of slot for which this or that screwdriver is intended, the dimensions here may be different. For straight tips this is the width and depth, for others the diameter of the screw. For Torx standardized number etc.

Over the years, the screwdriver has undergone a number of improvements. For example, very convenient screwdrivers with a ratchet, the so-called «ratchet». Thanks to this solution, working with a screwdriver becomes more convenient. There's no need to grip the handle as the rod slides freely in one direction without force, returning the hand without the need to unclip or re-install the screwdriver tip into the slot. You can simply work with one hand, and the direction of free return of the rod is adjusted with a special lever or clutch.

Popular sets with tips... The screwdriver in them is a stick with a handle, at the end of which instead of a tip a bit holder is installed in the form of a clamp or a square or hexagonal tip. The kit includes a set of bits (replaceable bits) of various types and sizes. As a result, we have a screwdriver and a set of tips for it - compact and practical.

Usually, the screwdriver shaft is 10 to 20 cm long, but for hard-to-reach places, sometimes a longer length is required, and sometimes, on the contrary, a shorter one. This is where variable length screwdrivers come in handy. Usually this is a retractable rod that is immersed in the handle and securely fixed in a more convenient position by a special mechanism.

There are different types of unusual handles: L-shaped and T-shaped. They allow you to increase the torque. The L-shaped or T-shaped handle can be tilted on some models so that the torque can be optimally adjusted.

For convenience when working in confined spaces, there are screwdrivers with a flexible shaft instead of a handle and even a gear reduction mechanism for working at an angle.

The shaft of the screwdriver does not have to be round, it can be either square or hexagonal, which allows you to turn the screwdriver not necessarily by hand, but also with a wrench, which will allow you to achieve a more significant torque.

If the operating conditions involve electrical voltages near the work area, or if the fasteners themselves are at dangerous voltages, then a dielectric-coated screwdriver with a handle guard should be selected. These screwdrivers have markings that reflect the voltage level against which protection is guaranteed.

When the screw socket is dirty, you need to tap the screwdriver. Not every screwdriver will handle this. Therefore, there are special screwdrivers with a heel on the handle for hammer blows... In such screwdrivers, the metal shaft passes completely through the handle and has a heel-shaped extension at the end.

For precision instrument work where it is necessary to tighten the adjusting resistor, adjust a small capacitor with adjustable capacitance, adjust the inductance of the inductor by moving the core, use all-ceramic or plastic screwdrivers to avoid distortion in electrical and electronic circuits.

Screwdrivers and electrification were not spared. Today in the market you can find electric screwdrivers, such as screwdrivers, pneumatic screwdrivers, drills - all these are progressive solutions to facilitate locksmith work.