Newcomb round-wire torsion-spring basic model

Newcomb round-wire basic formula uses empirical constant10.8 and deflection in revolutions; degree input is divided by360. Linear-elastic spring-body approximation excluding arm flexibility, curvature stress concentration, hysteresis, buckling, fatigue and allowable stress checks. Not a safe-load approval or garage-door spring selection/tensioning guide. Input limits do not establish allowable deflection.

Newcomb round-wire basic formula uses empirical constant10.8 and deflection in revolutions; degree input is divided by360. Linear-elastic spring-body approximation excluding arm flexibility, curvature stress concentration, hysteresis, buckling, fatigue and allowable stress checks. Not a safe-load approval or garage-door spring selection/tensioning guide. Input limits do not establish allowable deflection.

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Result

Enter your values and run the tool to see your result.

How to use this tool

Check the units, enter your values, and run the tool. Results follow the assumptions and method below.

Calculation method

Basic spring rate per degreeyoung*wire^4/(10.8*coils*meanDiameter*360)
Basic-model torqueyoung*wire^4/(10.8*coils*meanDiameter*360)*angle
Nominal bending stress before curvature correction32*(young*wire^4/(10.8*coils*meanDiameter*360))*angle/(pi*wire^3)
Unloaded inside diametermeanDiameter-wire
Unloaded outside diametermeanDiameter+wire

References