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]

Guiding values for solder joint strength

Soft solder alloys

Brazing filler metals