Welding Brazing and Soldering
Explain the difference between brazing and soldering - Answer-• Soldering and brazing differ only in that
soldering takes place at a temperature below 840 degrees F (450 C) and brazing occurs at a temperature
above 840 degrees F (450 C).
2. How does capillary action separate brazing from braze welding? - Answer-• Capillary action is the
force that pulls water up into a paper towel or pulls a liquid into a very fine straw. Braze welding does
not need capillary action to pull filler metal into the joint.
• Capillary action is required for brazing. The joints being brazed are spaced apart by a very small
amount which allows capillary action to draw the filler metal into the joint when the parts reach the
proper phase temperature.
5. What is the effect of joint spacing on joint tensile strength? - Answer-• As the joint spacing decreases,
the surface tension increases the tensile strength of the joint.
• In Brazing the parts being joined must be fitted so that the joint spacing is very small,
approximately .025 in to .002 in.
6. Why are braze joints subject to fatigue failure? - Answer-• As a joint is bent, the less ductile base
materials cause a shear force to be applied to the filler metal resulting in joint failure. Fatigue failures
may also be the result of vibration.
• Fatigue resistance of a metal is the ability to be bent repeatedly without exceeding its elastic limit and
without failure. For most soldered or brazed joints fatigue resistance is fairly low.
• Ductility - Answer-of a joint is its ability to withstand a force parallel to the joint. For a solder or braze
joint, the shear strength depends upon the amount of overlapping area of the base parts. The greater
the area that is overlapped, the greater is the strength.
Explain the difference between brazing and soldering - Answer-• Soldering and brazing differ only in that
soldering takes place at a temperature below 840 degrees F (450 C) and brazing occurs at a temperature
above 840 degrees F (450 C).
2. How does capillary action separate brazing from braze welding? - Answer-• Capillary action is the
force that pulls water up into a paper towel or pulls a liquid into a very fine straw. Braze welding does
not need capillary action to pull filler metal into the joint.
• Capillary action is required for brazing. The joints being brazed are spaced apart by a very small
amount which allows capillary action to draw the filler metal into the joint when the parts reach the
proper phase temperature.
5. What is the effect of joint spacing on joint tensile strength? - Answer-• As the joint spacing decreases,
the surface tension increases the tensile strength of the joint.
• In Brazing the parts being joined must be fitted so that the joint spacing is very small,
approximately .025 in to .002 in.
6. Why are braze joints subject to fatigue failure? - Answer-• As a joint is bent, the less ductile base
materials cause a shear force to be applied to the filler metal resulting in joint failure. Fatigue failures
may also be the result of vibration.
• Fatigue resistance of a metal is the ability to be bent repeatedly without exceeding its elastic limit and
without failure. For most soldered or brazed joints fatigue resistance is fairly low.
• Ductility - Answer-of a joint is its ability to withstand a force parallel to the joint. For a solder or braze
joint, the shear strength depends upon the amount of overlapping area of the base parts. The greater
the area that is overlapped, the greater is the strength.
