Steel rule or scale.
Steel Rule
Almost all of us use scale especially in student life. We know how to use it. But I want to discuss some other details about scale.
Industrial name is Steel rule. The most common measurement that we take is length. The most common instrument to take linear measurement directly is steel rule or steel tape.
STEEL RULE- It is a strip of metal (tempered spring steel or stainless steel) whose sides are right angled to each other and parallel. Standard units are graduated on it. The dimension can be taken directly and many times we use compus or caliper. Steel tape is also defined as a rule of flexible type.
SIZES- The available sizes of steel rule are used in daily life or in daily work is 6’’ ,12”,24” and equivalent to metric size that is in cm. Steel tapes are available in 6 ft,15 ft, 25 ft 50 ft and also available in Indian system.
GRADUATIONS-The English system of Linear unit ,we can get 1/64 of an inch (the least count) .The multiplication of 1/64 inch,1/32 inch,1/16 inch,1/8 inch ,1/4 inch etc are graduated on it.
For units of metric system the least count of steel rule is 0.5mm. The millimeters and centimeters units are also available.
TYPES-The following types of steel rule and tape are available-
a) Standard steel rule- This is the most common type of steel rule. They are made six inch, twelve inch and twenty four inch in length. In CGS system these are available from 150mm to 600mm. The graduation in inch is lowest 1/64 inch and fourth division of an inch is also available. In metric system the graduation is 0.05mm (lowest) and mm, cm are also available.
b) Flexible rule or tape- This type of rule is made of thin steel strip or made of plastic or cloth also with ½ inch width and generally length is 6 feet. These are available in a steel case or open. These tapes are very convenient to measure even curve surface.
c) Hook rule- Hook rule consists of six inches rule with a hook at the end. It is used to take measurement by supporting at the end of any things. The measurement can be taken by inside calipers and can easily get from this rule or scale.
d) Shrink rule-This type of rule has the graduations not in standard units. A slight larger than the standard graduation is made to allow the shrinkage of molten materials. It is mainly used by the pattern makers to make the pattern slight larger than the actual size because the molten materials shrinks always in cold stage. The graduations for different materials are marked on this.
e) Boxwood rule or folding rule-Generally it is used in carpenting shop. These are made of a length of two feet and can be folded for easy handling.
f) Key seat rule- It is a combination of a rule and a fixture. It is used to mark parallel lines on a cylindrical object as the key way of a shaft.
g) Narrow rule- It is used to measure narrow slots as these are made with less width.
CARE- It is an important measuring tool , so handle with great care. Its edge should be plane and should not use any sharp things to mark.
Like it on Facebook, Tweet it or share this article on other bookmarking websites.