How to measure a compression spring

You measure compression springs by writing down the following parameters step by step.
You will need a compression spring to follow this guide:

Step 1: Measure the spring wire diameter up to 2 decimals. Take wire diameter in the middle of the compression spring ( not one of the ends )

Measure Wire diameter

Step 2: Measure the outside diameter of one of the coils in horizontal state. Coils can have a slight variation of outside diameter always take the largest one.
Note, if the outside diameter changes to mutch, please look at conical compression springs, or other kinds of compression springs.

Measure Outside diameter

Step 3: Measure the length in its uncompressed condition. (without any force applied)

Measure free length

Step 4: Determine the ends on the compression springs. Compression springs can have the following ends:

    • Open
    • Open and grinded
    • Closed
    • Closed and grinded

Read more about the ends on compression springs.

Step 5: Count the number of coils. Also take in account the coils on each end.

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Counting ends on Compression springs

     

 

Open

Open and grinded

Closed

Closed and grided

Nt

Na

Na + 1 (0,5 + 0,5)

Na +2

Na+2

Hoogte
(Na
Nt

(Na+1) d

 

(Nt+1) d

Na d

 

(Nt+1) d

(Na+3) d

 

(Nt+1)d

(Na+2) d

 

Nt d

Pitch

p

(FL-d)/ Na

FL/ Na

(FL-3*d)/ Na

(FL-2*d)/ Na

number of coils

 

Step 6: Determine the spring wire material type. Wire types can be determined with an magnet, or by operation (high/low temperature exposure, corrosive materials, ect. ) In absence of that, most common material is music wire.