coil spring calculator

➤ calculate spring index
➤ calculate total shear stress
➤ calculate spring axial deflection
➤ calculate spring stiffness

calculate spring index

`C = D/d`
c = spring index
d = spring diameter
d = wire diameter

enter a value:

spring diameter (d):
m
wire diameter (d):
m

calculation result:

spring index (c):

calculate total shear stress

`τ = [8×F×D×K_W]/[π×d^3]`
`K_W = [4C-1]/[4C-4]+[0.615]/C`
τ = total shear stress
f = axial force
d = spring diameter
d = wire diameter
Kw = val coefficient
c = spring index

axial force (f):
spring diameter (d):
wire diameter (d):

calculation result:

total shear stress (t):
Newton/Meter2
spring index (c):
val coefficient (kw):

calculate spring axial deflection

`δ = [8×F×C^3×N]/[G×d](1+0.5/c^2)`
δ = spring axial deflection
f = axial force
d = wire diameter
n = number of effective coils
g = modulus of rigidity
c = spring index

enter a value:

axial force (f):
N
spring diameter (d):
m
wire diameter (d):
m
number of active coils (n):
modulus of rigidity (g):
N / m2

calculation result:

spring axial deflection (δ):

calculate spring stiffness

`K= [G×d]/[8×C^3×N]`
k = spring stiffness
d = wire diameter
n = number of effective coils
g = modulus of rigidity
c = spring index

enter a value:

spring diameter (d):
m
wire diameter (d):
m
modulus of rigidity (g):
N / m2
number of active coils (n):

calculation result:

spring stiffness (k):
coil spring calculator

usage example
input data: spring diameter d: 14 ​​meters; spring wire diameter d: 2 meters, click "calculate" to display the results.

output result: spring index, winding ratio is 7.
spring index c affects the strength, stiffness, stability and ease of manufacturing of the spring. the c value is large, the pitch diameter d is large, the wire diameter is small, the spring is soft, the stiffness is small, and it is easy to deform and wind up. on the contrary, if the c value is small, the spring is harder, has high rigidity and is not easy to wind. it is generally recommended to take 4≤c≤14 during design.
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