Wednesday, November 20, 2013

Self Tapping Screws And Other Linear Actuators

By Bonnie Contreras


Another name for self tapping screws is self drilling screws. The clue is in the name. They drill the hole in the metal for you so you do not have to drill what is called a pilot hole first. This is useful when you want to mount things like computer monitors onto metal shelving because you do not have to fiddle around matching up holes, you just drill the screw through everything and you only have to do it once.

These are wonderful, time-saving devices. You can mount sheet metal or corrugated metal to a steel frame easily and quickly without tearing your hair out or swearing at anybody. They are also useful for mounting surveillance cameras. Other uses for a self-drilling screw include surgery and dental implants.

Self drilling screws may have either crosshead (Phillips) heads or plain ones. Crossheads give the screw more more leverage when being driven through metal. You can see how important it is to make sure you have the correct tool for the job at hand. Such a tiny modification in form can translate to a significant change in function.

Most screws have a right-handed, or clockwise, thread. To tighten, turn clockwise; to loosen, turn counter-clockwise. The easy way to remember this is righty-tighty, lefty-loosey. The same mnemonic works for opening and closing jars as well as adjusting the radiator.

There are a wide variety of screw types. The distance between threads along the shaft, for example, is called the pitch. The metal from which they are made is also a factor; this can be steel, zinc, copper, nickel, brass or chromium. They can have flat or round heads and one or two grooves in the head. The ones with two grooves that are at right angles to each other are called Phillips head or cross head screws.

The guy who invented the ingenious screw was named Henry Phillips. He purchased the rights to the design from his pal, John P. Thompson. He tweaked the design a bit and then had it patented. He first sold the device to General Motors, who used it in the Cadillac. Phillips sold the patent in 1945 to Ford Motor Company for a sum of five million dollars. This is a huge amount of money today and a huge amount of moolah way back then.

When a screw is likely to face strong counterclockwise torque, which would loosen a right-handed screw, a left-handed screw is the correct choice. For instance, the left side of a bicycle has a left-handed thread. Anything with helical threads can legitimately be called a screw. The propeller of a ship is an example, as is an Archimedes' screw water pump.

It is really fun to watch self tapping screws in action. You can get quite a lot of work done in very little time, a satisfying prospect. Juggling two or more pieces of material together and trying to get the screw to hold can be tricky and exasperating. In many ways, simple devices are better than more complicated ones. There are a number of varieties of screw. They have different diameters and different distances between individual threads. They are manufactured from several different types of metal, including copper, nickel, chromium, brass, zinc and steel. Another important difference is in the construction of the screw's head, whether it is flat, round, plain or Phillips headed.




About the Author:





0 التعليقات:

Post a Comment

Search