National Torque Tools NZ Ltd.

Bolt Torque Calculator

Bolt Torque Calculations      Conversion Factors        
  Input here       Input here        
Diameter (D) inches   Diameter (mm) = Inches  
Thread Pitch T.P.I.   Pitch (mm) = T.P.I.  
Yield Strength (Sy) P.S.I.   Sy (kgf/mm2) = P.S.I.  
Joint type (P)     Sy (N/mm2) = P.S.I.  
Stress Area (As) in^2            Instructions for use  
Nut Factor (K)     Select relevant factors from the tables below for joint type, yield strength & nut factors. This calculator is for imperial fasteners, use the conversion factors above if you have metric fasteners.          
This calculator is intended as a guide only. If the application is critical then use the services of a design engineer.                            
 
         
Bolt Torque T = ft/lbs    
= in/lbs    
= Nm    
                   
Joint Type P     Sy (Imperial) P.S.I.   Sy (Metric) P.S.I.  
Shear 0.1 to .02     A193 B16 (2.5" & under) 105000   3.6 25602  
Tension (gasket) 0.35 to 0.4     A193 B16 (2.5" to 4") 95000   4.6 34136  
Tension (no gasket) 0.5 to 0.6     A193 B16 (over 4") 85000   4.8 45515  
Vibration 0.7 or more     A193 B7 (2.5" & under) 105000   5.6 42670  
Bolt Stretch measured 0.85 to 0.95     A193 B7 (2.5" to 4") 95000   5.8 56893  
Structural Shear 1.0 or more     A193 Gr B8 30000   6.8 68272  
        A193 Gr B8C 30000   8.8 91030  
Nut Factor K     A193 Gr B8M 30000   9.8 102408  
Moly paste 700F 0.067     A193 Gr B8T 30000   10.9 128010  
Anti-seize HD 2400F 0.085     J429 Gr 4 100000   12.9 153612  
Copper anti-seize 1800F 0.10     SAE J429 Gr1 36000        
Nickel anti-seize 2600F 0.11     SAE J429 Gr2 (3/4" to 1-1/2") 36000        
Copper-graphite anti-seize 1800F 0.10     SAE J429 Gr5 (1" to 1-1/2") 81000        
API SA2 0.117     SAE J429 Gr8 (1/4" to 1-1/2") 130000        
Machine oil 0.15     SAE J429 Gr8.1 (1/4" to-1/2") 130000        
As received, Alloy or Mild Steel .20     SAE J429 Gr8.2 (1/4" to 1") 130000        
As received, Stainless Steel .30                
Cadmium plate (dry) .20                
Zince plate (dry) .30                
                   

Torque Conversion

Input   Torque Conversion Factors                
Data     Imperial     S.I.     Metric  
Here Units ozf.in lbf.in lbf.ft N.m cN.m mN.m gf.cm kgf.cm kgf.m
ozf.in =
lbf.in =
lbf.ft =
N.m =
cN.m =
mN.m =
gf.cm =
kgf.cm =
kgf.m =

Automatic recalculation 

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