Design information for engineers, such as spring calculation formulas,
which are the basis of spring design, can be found here.
The symbols used for spring design are shown in Table 1 below. The values of the transverse elastic modulus (G) are based on Table 2.
Table 1. Symbols and units used in calculations
|Symbol||Meaning of Symbol||Unit|
|a||Material width (perpendicular to the central axis)||mm|
|b||Material thickness (a = b for square cross-section, parallel to the central axis)||mm|
|D||Coil center diameter||mm|
|Di||Coil inner diameter||mm|
|Do||Coil outer diameter||mm|
|Nt||Total number of coils||—|
|Na||Number of active coils||—|
|G||Transverse elastic modulus||N/mm2|
|P||Load applied to the spring||N|
|τ||Torsional correction stress||N/mm2|
|β||Stress calculation coefficient|
|γ||Deflection calculation coefficient|
Table 2. Transverse elastic modulus: G（N/mm2）
|Spring steel material||7.85×104|
The basic formula for calculating the deflection at the time of compression is calculated using
The basic formula for the spring constant is calculated by
The basic formula for stress during compression is The calculation coefficients β and γ differ depending on the spring index (c) and the rectangular shape. Please contact us separately for further details.