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Calcimator

Connection Design Calculator

Calculate bolted steel connection capacity: shear, bearing, and overall connection strength for A325 and A490 bolts.

Inputs

mm
(1=A325, 2=A490)

AISC 360 Table J3.2: A325 Fu=830 MPa (common); A490 Fu=1040 MPa (high-strength); use A325 default

bolts
mm
(1=bearing, 2=slip-critical)

Results

Shear Capacity

264,012 N

Connection Capacity

264,012 N

Bearing Capacity777,600 N
Demand/Capacity Ratio0
How to Use This Calculator
  1. Enter the design shear force and tension force at the connection in kips.
  2. Select the connection type (bolted, welded, or combination).
  3. Input the bolt diameter or weld size and the steel grade.
  4. Review the Number of Bolts Required or Weld Length Required and the Connection Efficiency.
  5. Check the Block Shear Failure output to confirm it does not govern over bolt shear.

How the result changes with Bolt Diameter

Bolt DiameterShear CapacityConnection Capacity
14129,366 N129,366 N
20264,012 N264,012 N
28517,463 N517,463 N
34762,994 N762,994 N

What each input means

Bolt Diameter
Nominal diameter of each bolt. Common sizes: 16, 20, 22, 24 mm.
Bolt Grade
Structural bolt grade per AISC 360 Table J3.2. ASTM A325 (ASTM F3125 Gr. A325): Fu=830 MPa, most common; ASTM A490 (ASTM F3125 Gr. A490): Fu=1040 MPa, for high-strength connections. A325 preferred for economy.
Number of Bolts
Total number of bolts in the connection.
Plate Thickness
Thickness of the thinnest connected plate for bearing check.
Connection Type
Select 1 for bearing-type (higher capacity) or 2 for slip-critical (more conservative).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Bolt Diameter = 20, Bolt Grade = 1, Number of Bolts = 4, Plate Thickness = 12 = 5 input(s) provided
  2. Calculate Shear Capacity
    Shear Capacity
    264012 = 264012
  3. Calculate Connection Capacity
    Connection Capacity
    264012 = 264012
  4. Calculate Bearing Capacity
    Bearing Capacity
    777600 = 777600
  5. Calculate Demand/Capacity Ratio
    Demand/Capacity Ratio
    0 = 0

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