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Calcimator

Weld Strength Calculator

Calculate weld strength for fillet and groove welds per AISC. Determine effective area, allowable load, and shear capacity with directional effects.

Inputs

in
in
psi
°

Results

Allowable Load

22,271 lb

≈ 7 small cars

Shear Capacity

22,271 lb

≈ 7 small cars

Effective Throat Area1.06 in²
Allowable Weld Stress21,000 psi
Factor of Safety2
How to Use This Calculator
  1. Enter the Weld Length in inches — for fillet weld returns subtract 2× the weld size per AISC.
  2. Enter the Weld Size (Leg) in inches for fillet welds, or throat thickness for groove welds. Common fillet sizes: 3/16", 1/4", 5/16".
  3. Enter the Electrode Strength (FEXX) in psi: E60XX = 60,000 psi, E70XX = 70,000 psi, E80XX = 80,000 psi.
  4. Select the Weld Type — Fillet for lap and T-joints, Groove (Butt) for full-penetration connections.
  5. Enter the Load Angle in degrees: 0° = longitudinal shear, 90° = transverse loading (strongest for fillets, ~50% stronger).
  6. Review Allowable Load in lb and Shear Capacity — if the applied load exceeds these, increase weld size or length.

How the result changes with Weld Length

Weld LengthAllowable LoadShear Capacity
2074,235 lb74,235 lb
70259,822 lb259,822 lb
130482,528 lb482,528 lb
180668,115 lb668,115 lb

What each input means

Weld Length
Total effective length of the weld. Subtract 2× weld size for fillet weld returns (AISC).
Weld Size (Leg)
Fillet weld leg size or groove weld throat. Common fillet sizes: 3/16", 1/4", 5/16", 3/8".
Electrode Strength (FEXX)
Electrode classification tensile strength. E60XX = 60,000; E70XX = 70,000; E80XX = 80,000 psi.
Weld Type
Fillet welds are triangular and join perpendicular surfaces. Groove welds fill a prepared joint for full penetration.
Load Angle
Angle between the load direction and the weld axis. 0° = longitudinal shear; 90° = transverse (strongest for fillets).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Weld Length = 6, Weld Size (Leg) = 0.25, Electrode Strength (FEXX) = 70000, Weld Type = 1 = 5 input(s) provided
  2. Calculate Allowable Load
    Allowable Load
    22271 = 22271
  3. Calculate Shear Capacity
    Shear Capacity
    22271 = 22271
  4. Calculate Effective Throat Area
    Effective Throat Area
    1.0605 = 1.0605
  5. Calculate Allowable Weld Stress
    Allowable Weld Stress
    21000 = 21000

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