 
Allowable stress
 
Joint shear stress
 
Minimum overlap length
 
Strength check
τ ≤ τ A
Design of optimum overlap length
Anticipates that any breakage occurs in the joint itself, and not in the basic material.
L opt = max {L min , L 1 }
where:
 
Meaning of used variables for metric units:
| S US | Joint strength in shear [MPa] | 
| k S | Shear safety factor | 
| F | Transferred force [N] | 
| b | Width of connected parts [mm] | 
| s | Thickness of connected parts [mm] | 
| S Ub | Tensile strength of basic material [MPa] | 
| L | Length of overlap [mm]. | 
Meaning of used variables for English units:
| S US | Joint strength in shear [psi] | 
| k S | Shear safety factor | 
| F | Transferred force [lb] | 
| b | Width of connected parts [in] | 
| s | Thickness of connected parts [in] | 
| S Ub | Tensile strength of basic material [psi] | 
| L | Length of overlap [in] |