What is the recommended penetration angle for the tungsten tip?

• A. 0° to 15°
• B. 20° to 40°
• C. 60° to 80°
• D. Between 60° and 90°

Answer: (D)

Penetration angle is how you tilt the tungsten electrode relative to the work so the arc enters the joint and heat is directed into the weld root. A steeper angle (closer to perpendicular to the work) concentrates heat into the joint, producing deeper fusion and penetration. That’s why aiming the tungsten tip between 60° and 90° gives the best chance of achieving proper deep penetration—the arc is directed into the joint rather than skimming the surface. Angles much lower than this spread heat across the surface and tend to produce shallower penetration, which can lead to incomplete fusion. So the recommended range is between 60° and 90° because it reliably concentrates heat into the joint to achieve the desired penetration.