|
|
|
|
|
Compression
Spring Terminology
Click
here
to
see a Glossary of Spring Terms
|
Formulas
for Spring Characteristics
|
|
|
Symbol
|
Meaning
|
| |
R
= |
Rate
per Inch |
| |
P
= |
Load
in pounds |
| |
S
= |
Stress
(uncorrected) |
| |
H
= |
Solid
height |
| |
G
= |
Torsional
modulus of elasticity |
| |
p
= |
Pitch |
| |
M
= |
Moment
or torque, in-lb |
| |
E
= |
Modulus
of elasticity |
| |
n
= |
Active
coils |
| |
N
= |
Total
coils |
| |
D
= |
Mean
diameter of coil |
| |
d
= |
Diameter
of wire |
| |
p
= |
Pi,
3.14 |
| |
L
= |
Free
length |
| |
T
= |
Revolutions
of spring |
| |
SK= |
Corrected
stress |
|
Torsional Modulus
of Elasticity Data
|
|
Steel
|
11.5
x 106 |
|
Stainless
Steel |
10
x 106 |
|
Chrome
Vanadium |
11.5
x 106 |
|
Chrome
Silicon |
11.5
x 106 |
|
Phosphor
Bronze |
6.25
x 106 |
|
Brass |
5.5
x 106 |
|
| Formula
Key |
|
Characteristic |
Formula |
|
Wire
diameter (d) |
d
= 8PD
3 piS |
|
Active
Coils (n) |
n
= Gd4
8RD2 |
|
Uncorrected
Stress |
S
= 8PD psi
piD3 |
|
Spring
rate (R) |
R
= (P2-P1)
(L-L2) |
|
By
Type of Ends |
|
Pitch
(p) |
Open |
Open
Ground |
Closed |
Closed
&
Ground |
|
p
= L-d
n |
p
= L
N |
p
= L-3d
n |
p
= L-2d
n |
|
Solid
height (H) |
H
= d(N+1) |
H
= dN |
H=d(N+1) |
H
= dN |
|
Active
coils (n) |
n
= N |
n
= N-1 |
n
= N-2 |
n
= N-2 |
|
Total
Coils (N) |
N
= L-d
p |
N
= L
p |
N
= L-3D +2
p |
N
= L-2d +3
p |
|
Free
length (L) |
L
= (pN)=d |
L
= pN |
L
= (pn)+3d |
L
= (pn)+2d |
|
| "K"
Factor |
|
|
|
|
|
|
 |
