1. What is Fillet Weld Throat?

The throat of a fillet weld is the shortest distance from the root to the face of the weld. It's a critical measurement that determines the strength of the weld joint, as it represents the minimum cross-sectional area that carries the load.

2. How Does the Calculator Work?

The calculator uses the fillet weld throat formula:

Where:

• \( Throat \) — Throat size (mm)
• \( Leg \) — Leg length of the fillet weld (mm)

Explanation: For an equal-leg fillet weld with a 90° angle between the joined pieces, the throat is calculated as the leg size divided by the square root of 2.

3. Importance of Throat Calculation

Details: Accurate throat calculation is essential for determining weld strength, ensuring structural integrity, and meeting design requirements in welding applications.

4. Using the Calculator

Tips: Enter the leg size in millimeters. The value must be greater than zero. The calculator will compute the corresponding throat size.

5. Frequently Asked Questions (FAQ)

Q1: Why is throat size important in welding?
A: Throat size directly determines the strength of a fillet weld. A larger throat means a stronger weld joint capable of withstanding greater loads.

Q2: Does this formula work for unequal leg fillet welds?
A: No, this formula is specifically for equal-leg fillet welds. For unequal legs, the calculation is more complex and depends on the specific geometry.

Q3: What is the relationship between leg size and throat size?
A: For a 90° fillet weld, the throat is approximately 0.707 times the leg size. This relationship comes from the geometry of a right triangle.

Q4: How does weld penetration affect throat size?
A: If a weld has penetration beyond the root, the effective throat may be larger than the theoretical throat calculated from leg size alone.

Q5: Are there industry standards for minimum throat sizes?
A: Yes, various welding codes (such as AWS D1.1 and ASME Section IX) specify minimum throat sizes based on material thickness and application requirements.