Step Tube Solder Joint Calculation Formulas
Allowable stress
Joint shear stress
Minimum step depth
Strength check
σ ≤ σ A
Design of optimum step depth
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:
and the joint factor f: |
| | for h 1 < h 2 : |
| | |
| | for h 1 > h 2 : |
| | 
|
Meaning of used variables for metric units:
S US | Joint strength in shear [MPa] |
k S | Shear safety factor |
S Ub | Tensile strength of basic material [MPa] |
d | Diameter of inner tube or step diameter [mm] |
L | Step depth [mm] |
h 1 | Tube thickness of inner tube [mm] |
h 2 | Tube thickness of outer tube [mm] |
Meaning of used variables for English units:
S US | Joint strength in shear [psi] |
k S | Shear safety factor |
S Ub | Tensile strength of basic material [psi] |
d | Diameter of inner tube or step diameter [in] |
L | Step depth [in] |
h 1 | Tube thickness of inner tube [in] |
h 2 | Tube thickness of outer tube [in] |
Guiding values for solder joint strength
Soft solder alloys
Brazing filler metals
