how to read a scale rule?

Answer 1

First, you use a scale to measure a distance on a drawing.

Second, the drawing will indicate the scale. ALWAYS check your scale against the scale bar.

For a typical 12" long engineers scale, for the 10 scale - 1" = 10', the stick is divided up into 10 units, and each unit is divided by 10. Each unit is 1 inch. The difference between an engineers scale and an architects scale is that we enginners use the decimal system. The architects scale uses the fraction system which is good for feet and inches. Engineers don't use inches. We use feet only.

Typical Eng. Scale is 1" = 50'
Typical Arch. Scale is 1/8" = 1'

For instance, 4' - 6" is an Arch. dimension. The same Eng. dimension is 4.5'.

For the engineers scale, say the 10 scale, each unit is divided by 10 so you can measure to the nearest tenth of an inch and thus tenth of a foot.

So for 1" = 40', you turn to the 40 side and for 1" = 100' you turn to the 10 side and multiply your measurement by 10.

For Arch. Scale, it takes practice.

Answer 2

If you looking at an architect's rule or an engineer's rule, they are similar in how they are read. They are triangle shaped and on each side of the triangle you will have two sets of engraved numbers on each side of the scale. The increments are broken down in inches and feet. If you have an engineer's rule it is usually broken down in 10th's. I am not as familiar with that rule as I am in the architectural side and only use an architect's rule.

Architects Rule/Scales are Engraved and numbered in 1/8, 3/32, 3/16, 1/4, 3/8, 1/2, 3/4, 1, 1 1/2, 3" to the foot and inch in 16ths. Usually Color coded and fully divided below zero.