Assembly and service
Stress, solid height, and stability
Body stress is only one part of mechanical evaluation.
Corrections and limits
In cylindrical helices, curvature and geometry raise stress above an elementary estimate. A body correction does not cover end concentrations, contact, defects, or fatigue criteria. The calculator reports an estimate, not allowable stress.
Closure and buckling
Near solid height, coils may contact and response ceases to be linear. Slender springs can deflect sideways depending on length, supports, and alignment; a slenderness warning is not a critical-load calculation.