Measurements

Question 1

What are the two major systems of measurements and where are they used?

Answer 1

The two major systems of measurements are:
* Inch system - US & Canada
* Metric system - 90% of the world

Question 2

Why are people still using the imperial system?

Answer 2

• It will take a long time to convert everything to metric
• All machine tools and measuring devices will have to be redesigned
• Devices created years ago with imperial system are still working
• People are resistaant to change

Question 3

What is the fractional/inch system?

Answer 3

the inch system is still used to identify the sizes of holes produced by drills, standard taps, and screw thread sizes.

Question 4

What makes fractional sizes impractical?

Answer 4

Increased use of CNC and digital data make fractional sizes impractical.

ANSI recommends decimal dimensions.

Question 5

What is the unit of length in the inch system?

Answer 5

The unit length used in this system is the inch.

Question 6

What are common fractions used in the fractional inch system?

Answer 6

Common fractions use in the fractional inch system are 1/2, 1/4, 1/8, 1/16, 1/32 and 1/64

THe fractional inch system is based on the binary system.

Question 7

What are common fractions used in the decimal-fraction inch system?

Answer 7

Common fractions used in the decimal-fraction inch system are:
1/10 (0.1), 1/100 (0.01), 1/1000 (0.001), 1/10000 (0.0001)

The numbers are written as products of 10 or a fraction of 10

Question 8

What is the metric system?

Answer 8

The metric system is a system of linear dimensions expressed in multiples and submultiples of the meter.

The mm is the most common. Fractions of tmm are stated as decimals.

Question 9

What is the metric equivalent of these imperial measurements?

Answer 9

• 1 yard (inches)
• 1 mile (kilometer)

Question 10

What is the imperial equivalent of these metric measurements?

Answer 10

• 1 meter (inches)
• 1 kilometer (miles)

Question 11

What tools are used to measure factional dimensions?

Answer 11

Percision intruments such as rules, vernier calipers and micrometers (for dimensions less than 0.5 mm or 1/64 in.) are used to measure fractional dimension

Question 12

What are the two types of steel rules?

Answer 12

The two types of steel rules are:
* Metric
* Fractional

Question 13

What is a a steel rule and what is used for?

Answer 13

Metric steel rules are graduated in millimeters and half millimeters.

Question 14

What is a disadvantage that comes with using a steel rule?

Answer 14

Steel rules provide linear measurements without greater accuracy

Question 15

What sizes are steel rules available in?

Answer 15

Steel rules are available in sizes from 15cm to 1m