Wave Spring Design Theory
There are 4 critical factors when considering a wave spring –
- Constraints of the application: Bore/shaft, ID/OD etc.
- Load
- Working height at which the load is applied
- Material desired
Wave Spring Design General Considerations
- If a spring is designed for static application, make sure that the % stress at working height is less than 100%. Spring will take a set if subjected to a higher stress.
- If a spring is designed for dynamic application, make sure that the % stress at working height is less than 80%. Spring will take a set if subjected to a higher stress.
- Few things to remember:
- If the work height per turn is less than (2 * Wire Thickness), the spring will operate in a 'non-linear' range and actual loads may be higher than calculated
- Number of turns must be between 2 and 20
- Number of waves per turn (N) must be in ½ increments
- Min. Radial wall = (3 * Wire Thickness)
- Max. Radial Wall = (10 * Wire Thickness)
- It is NOT recommended to compress a wave spring to solid
OD expansion and OD tolerance must be taken into account while designing a spring to fit in a bore and/or over a shaft
Wave Spring Nomenclature:

Formulas:
Operating Stress, 
Design stresses for wave springs: |
Static/Low Cycles |
|
|
No preset |
: |
100% of tensile strength |
Preset springs |
: |
150% of tensile strength |
Dynamic Service |
|
|
104 cycle life |
: |
80% of tensile strength |
105 cycle life |
: |
53% of tensile strength |
106 cycle life |
: |
50% of tensile strength |
107 cycle life |
: |
48% of tensile strength |
Fatigue Stress Ratio, 
Where:
s = Material tensile strength
S1 = Calculated operating stress at lower working height (must be less than s)
S2 = Calculated operating stress at upper working height
X |
|
Estimated Cycle Life |
< .40 |
: |
Under 30,000 |
.40 - .49 |
: |
30,000 – 50,000 |
.50 - .55 |
: |
50,000 – 75,000 |
.56 - .60 |
: |
75,000 – 100,000 |
.61 - .67 |
: |
100,000 – 200,000 |
.68 - .70 |
: |
200,000 – 1,000,000 |
> .70 |
: |
Over 1,000,000 |
Deflection,
Spring Rate, 
Multiple Wave Factor (K): |
N |
2.0-4.0 |
4.5-6.5 |
7.0-9.5 |
10.0 & Over |
K |
3.88 |
2.9 |
2.3 |
2.13 |
OD Expansion = (0.02222 Rw N T) + b
Where:
