Phillips screwdriver is not an easy story
Screwdriver - a manual bench tool designed to screw and unscrew fasteners with threads, most often screws and screws, on the head of which there is a slot (groove). Usually it is a metal rod with a tip and a handle (plastic or wooden).
A Phillips screwdriver is an indispensable attribute of any tool kit of your father or any workshop. But the history of its invention in the 1930s was not immediately accepted by the community.
The first appearance of classic screws for screwdrivers with a “flat” tip dates back to about the 16th century, and they existed almost unchanged until the beginning of the 20th century. By this time, slotted screws were already causing a lot of complaints, but were out of competition because of their cheapness. The disadvantages of the "classic" screws were especially pronounced during mass assembly, in particular in the automotive industry. Firstly, the sting was not centered, because of this, mechanical screwdrivers often slipped away, leaving scratches on the varnished body parts. Secondly, when tightening the screws and screws often “pulled”, turning the head or damaging the fasteners. It was these limitations that the American inventor John Thompson was going to overcome, in 1933, patenting a screwdriver with a cross-shaped sting and a screw with the corresponding head. However, an attempt to sell the invention to hardware manufacturers was unsuccessful. In 1934, Thompson met the engineer Henry Phillips and told him the essence of his invention. Phillips liked the idea, he bought the rights to Thompson's patent and organized the Phillips Screw Company (it still exists). In 1936, he improved the technology and developed a method for mass production of screws. The cross screws automatically centered the screwdriver, and also did not allow “pulling” - the sting of the tool simply slipped.
However, Phillips everywhere waited for failures. Finally, he managed to interest Eugene Clark, president of American Screw Company, the largest manufacturer of hardware in the United States. Although the company’s engineers objected, Clark was so captivated by the idea that he threatened to “fire anyone who says it’s impossible to do.” The threat took effect, and the company, having invested in the organization of production of half a million dollars, began to produce screws under the "cross". In 1937, GM first used these screws in the production of Cadillac models. The results were so brilliant that by 1940 all American automakers had switched to using cross screws, and metalware manufacturers lined up in dozens of queues to buy a license. During World War II, manufacturers of military equipment, such as tanks and aircraft, also switched to the use of these screws.
Since then, many different screws have been invented - both for polyhedrons and for stars of various shapes. But, despite this, Phillips cross screws and screws (in English sources they are named after the inventor - Phillips) are still the standard, and a Phillips screwdriver is the basis of any tool kit.
The simplest screwdriver is usually a rod with a tip, which when inserted into the slot, the other end of the rod is equipped with a wooden, plastic or rubber handle. The material of the handle and its shape are selected based on considerations of increasing adhesion to the hand.
The diameter of the handle is usually in the range of 10 to 40 mm. Since the relationship between the diameter of the handle and the torque delivered to the part is direct, usually the larger the diameter, the larger the size of the parts for which the screwdriver is designed. Therefore, screwdrivers designed for small parts are equipped with thin handles to prevent tearing of a slot or thread or tearing of a part. Some screwdrivers have a hole in the handle that allows you to increase the torque when using the lever threaded into this hole, or is used to secure the safety cord.
The tip of the screwdriver wears out due to the action of significant mechanical stresses during operation. To increase the life of the tip, it is made from special wear-resistant and durable alloys, for example, from chromium-vanadium-molybdenum steels.
Types of tips
Depending on the type of slot on the part head, screwdrivers with various types of tips are used.
Standard - Gained ubiquitous.
- Straight slot (slotted) is the simplest and historically first type of slot.
- Phillips - Cross-shaped, self-pushing. At the moment, it is outdated, but continues to be widely used in instrumentation, as it is a de facto standard and takes up little space in the head.
- Pozidriv is an advanced version of the Phillips slot, a non-self-pushing. Due to the large depth of the slot, it is used only where the screws are forced to have large heads: in furniture production and construction. However, it is in these industries that a large torque is needed, which is fundamentally impossible for Phillips.
- Hexagonal slot - allows you to get a lot of torque.
- Torx (star-shaped six-beam) - allows you to get great torque, used in the manufacture of household appliances, mechanical engineering.
Special - If special requirements are imposed on the screw, such as beauty, protection against twisting or a huge tightening force in a compact head, special slots are used.
- Tri-Wing (three-blade) - used in the aerospace industry and in the manufacture of electronic devices.
- Torq-Set (asymmetric cruciform) - used only in the aerospace industry.
- One-way - not intended for twisting.
- Two-pin (spanner) - used in elevators and other places where beauty and vandal protection are required at the same time.
- Slotted with a slot, similar to a spanner, is used in electrical appliances, power supplies, where amateurish intervention is undesirable.
- Torx with a pin (Torx Tamper Resistant) is a six-pointed star with a hole in the middle where the pin enters in the middle of the six-pointed screw recess.