Engineering Calculators
ANSI Hardware Guide | ISO Hardware Guide
Torque Engineering and Design | Strength of Materials

The following calculator will determine the preload engineering data of a stud and nut installtion or other fastener under the load of torque. All engineering units must be entered consistant.

Equations used:

 Input Number Displayed in BOLD, Results in RED, All units in N, mm, degrees Description Input Number of bolts Young's modulus of bolt Poisson ratio of bolt Young's modulus of flange Poisson ratio of flange Upper flange thickness Lower flange thickness Total resulting effective flange thickness Bolt diameter Bolt thread root diameter Bolt clearance hole Bolt head diameter Nut thickness (enter 0 if threaded into flange) Thicknes of bolthead Bolt length assumed equal total effective flange thickness Cone angle Preload force applied to a bolt Maximum bolt stress % of max stress used by bolt preload Description Stiffness Results Tensile stiffness of a bolt shaft Shear stiffness of a bolt head Shear stiffness of a nut Total stiffness of all bolts Compressive stiffness of top flange in series with bottom fl Shear stiffness of top flange in series with bottom flange Total stiffness of all flange elements under all bolts Ratio flange-to-bolt stiffness total joint stiffness Description Force Results Maximum allowable force on a bolt Total force that can be applied to joint till joint preload is l Force added to each bolt preload force by Fleak Total force on a bolt when the joint starts to leak Force on joint at which bolts break Preload stress in a bolt (based on thread root diameter) Total stress in a bolt when joint begins to leak % of max stress used by total bolt load Fbreak/Fleak: resulting safety factor Preload Description Joint stiffness Joint stiffness pressure (N/mm/mm2) Diameter of stress cone at center of flange (joint) Area of stress cone at flange joint Area under bolt head Joint stiffness under bolt head Joint stiffness flange-to-flange