Step Solder Joint Calculation Formulas

Metric units

Joint allowable stress

Shear stress from force

Shear stress from moment

Resulting reduced stress

Strength check

τ red τ A

Minimum step depth

Design of optimum overlap length

Anticipates that a joint is designed so 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 tension [MPa]

k S

Shear safety factor

S Ub

Tensile strength of basic material [MPa]

F

Transferred force [N]

d

Step diameter [mm]

L

Step depth [mm]

T

Torque [MPa]

English units

Joint allowable stress

Shear stress from force

Shear stress from moment

Resulting reduced stress

Strength check

τ red τ A

Minimum step depth

Design of optimum overlap length

Anticipates that a joint is designed so 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 tension [MPa]

k S

Shear safety factor

S Ub

Tensile strength of basic material [MPa]

F

Transferred force [N]

d

Step diameter [mm]

L

Step depth [mm]

T

Torque [MPa]

Guiding values for solder joint strength

Soft solder alloys

Brazing filler metals