The Mystery of the Architect Scale Ruler

Everyone knows how to use an inch ruler. And most people know how to use a metric ruler. It doesn’t matter that there are 2.54 centimeters per inch. A centimeter is a centimeter. But, if you remember when you saw an architect scale ruler for the first time, you will agree that the scales are a

Architect Working on Plans
Architect Working on Plans

mystery. There are several scales on the same ruler. There are (1/8, ¼), (½, 1), (3/8, 3/4), (3, 1½). What do these scales mean?

Let’s bring in a blueprint. Now you need that architect scale ruler to measure the size of objects on the blueprint. Since the objects are drawn at a scale of the original size, you need to match up that scale with the corresponding scale on the ruler.

How do you choose the correct scale? Look in the bottom right corner of the blueprint. There is a box of useful information. It has the name of the drawing, the date drawn, the architect name, and the scale that it was drawn with. If the scale is 1/8, then every 1/8″ on the paper represents 1 foot (or 1 mile, etc) in reality. So you would use the 1/8 scale on the architect ruler. Where the ruler says 16, the reality measurement is 16 feet (or 16 miles, etc). It doesn’t matter right now that the measurement on the paper is 2 inches. That’s too much information. Let the ruler do the work for you.

Congratulate yourself. Now you can consider yourself proficient at using an architect scale ruler.

 

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How to Use an Architect Scale Ruler

An architect scale ruler can come in many sizes and gradations. For now, let’s keep it simple, just to get started. Here is how these handy rulers can make reading a blueprint very easy.

  • First, look in the title block of the blueprint, which is usually located in the bottom right hand corner. It will tell you which scale to use. If it says: 1/4″=1′, then you will be using the 1/4 scale on the architect ruler. That means, 1/4″ on the blueprint represents 1 foot in the actual size of the object. If it says: 1/8″=1′, then you will be using the 1/8 scale on the architect ruler. Many other scales are used, because of the size limits of the paper the drawing is put on, and the actual size of the object or building or landscape.
  • Now, simply use the correct scale to measure the actual size of each part of the drawing.
  • Fine-tuning: You will notice that the zero mark is not the first mark on the scale. It is preceded by some very small gradations. These gradations could have been printed on the entire scale, but that would be very hard on the eyes. Let’s say you are measuring a line that is between 5 and 6 units. Now put the 5 mark on one end of the line. Look now to the other end of the line where it lines up with the very small gradations. Here you can read how much more than 5 units the line is.
  • If this sounds a little confusing, just give it a try, and you will see how easily you will catch on.

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How to Use An Architect Scale Ruler

How To Read Blueprints
How To Read Blueprints

To use an architect scale ruler is not an easy task. Since these rulers come in many configurations, you first must know which scale to use. Here are the basic steps:

    1. Find the scale needed in the Title Block of the blueprint. If it says 1/8″ equals 1 foot, then go to the next step.
    2. Use the right scale. 1/8, 1/4, etc. The 1/8 scale means that the markings are 1/8″ apart. The 1/4 scale means that the markings are 1/4″ apart.
    3. Lay the scale on the blueprint and measure your object. If you are using the 1/8 scale, and the object is at mark 5 on the scale, then it is 5 feet long.
    4. Accuracy. If the object is not an even number of markings on your scale, you can get the accurate measurement by using the fine markings before the zero mark. Say the object is between 5 and 6 on your scale. Just slide the final mark (5 in this case) to the end of the object. Then you can read the answer as 5 marks plus whatever the object lines up with in the fine markings below the zero mark.

There are complete instructions shown here:

How to Use An Architect Scale Tape
How to Use An Architect Scale Tape

 

 

How to Use an Architect Scale Ruler

Architect Scale Rulers
Architect Scale Rulers

To operate an architect scale ruler, first look at the Title Block on the blueprint. It is located in the bottom right corner. This area contains valuable information to help you choose the correct scale: title of the drawing, the owner or customer of the project, names of the designer, drawer, pertinent ID numbers, and the supervisors. It has the page number, if multiple pages are involved, and the version number. It also has areas for the signatures of those who approved the drawing, and the dates they approved it.

There is also a small block that says what scale the drawing was made in.  This is what you really need. Some examples are: 1″ = 30′, 1/4″=1′, 1/8″=1′, 1/2″=1’0″. If it is 1/8=1′, then use the side of the tape (more)……

 

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