### Solder Joint - Lap Joint Calculation / Formula

**Solder Joint Design Calculations**

Solder lap joint equations for stress in tension, stress in shear, tensile stress in brazed joint.

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Preview Solder Lap Joint Strength Calculator

Allowed Joint stress loading equation:

τ_{A} = S_{US} / k_{s}

Joint shear stress equation:

τ = F / ( b · L )

Minimum overlap length of solder surface formula:

L_{min} = F / ( b · τ_{A} )

Strength check of solder line:

τ ≤ τ_{A}

Optimum overlap length formula:

Anticipates that any breakage occurs in the joint itself, and not in the basic parts material equation:

L_{opt} = max {L_{min}, L_{1} }

where:

L_{1} = ( S_{Ub} · s ) / S_{US}

where:

S_{U} = joint strength in shear of solder [psi, MPa],

k_{S} = shear safety coefficient factor (typically 2 or greater),

F = transferred force [lb, N],

b = width (minimum) of connected parts [in, mm],

s = thickness of connected parts (in, mm],

S_{Ub} = Tensile strength of basic part material in axial loading [psi, MPa],

L = Length of overlap (in, mm).,

L_{1} = Minimum length of over lap on parts strength (in, mm).

Reference:

Kent's Machine Engineers Handbook, 12th Edition Design and Production, 1950 Colin Carmichael

Related web pages:

- Solder Lap Joint Calculator / Formulae
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