Bolt Shear & Bearing Calculator

Bolted connection — shear and bearing resistance per EN 1993-1-8 (EC3) §3.6

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Bolt & Connection Parameters

Bolt
pcs
Total bolts in connection
kN
Design value (factored)
Plate (governing for bearing)
mm
Thinnest plate in joint
mm
Min = 1.2 d₀
mm
Min = 1.2 d₀
mm
Min = 2.2 d₀
mm
Min = 2.4 d₀

Results

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Enter values
Shear resistance Fv,Rd per bolt
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Bearing resistance Fb,Rd per bolt
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Governing FRd per bolt
—
Total resistance n × FRd
—
Applied VEd
—
Utilisation η
—
Reserve capacity
—
Bolt area used
—
Edge distance e₁ < 1.2 d₀ — minimum not satisfied (EC3 Table 3.3).
Edge distance e₂ < 1.2 d₀ — minimum not satisfied.
Spacing p₁ < 2.2 d₀ — minimum not satisfied.
Spacing p₂ < 2.4 d₀ — minimum not satisfied.
Utilisation > 80% — consider more or larger bolts.
Shear governs — consider higher bolt grade to improve resistance.
Bearing governs — consider increasing edge distance or plate thickness.

Connection Diagram

Bolt Data Reference

Size d (mm) d₀ (mm) A shank (mm²) As thread (mm²) Min e₁ Min e₂ Min p₁ Min p₂

Calculation Method — EC3 §3.6

Shear resistance per bolt

Fv,Rd = αv · fub · A / γM2

  • Shank (unthreaded) shear plane: αv = 0.6 — all grades
  • Thread (As) shear plane: αv = 0.6 for 4.6, 5.6, 8.8 — else 0.5 (6.8, 10.9, 12.9)
  • A = As (thread) or A (shank) depending on shear plane location
  • γM2 = 1.25

Bearing resistance per bolt

Fb,Rd = k₁ · αb · fu · d · t / γM2

  • k₁ = min(2.8e₂/d₀ − 1.7, 1.4p₂/d₀ − 1.7, 2.5)
  • αb = min(e₁/3d₀, p₁/3d₀ − ¼, fub/fu, 1.0)
  • fu = ultimate strength of plate material

Spacing limits (EC3 Table 3.3)

  • e₁ ≥ 1.2 d₀ (min) / ≤ 4t + 40 mm (max)
  • e₂ ≥ 1.2 d₀ (min) / ≤ 4t + 40 mm (max)
  • p₁ ≥ 2.2 d₀ (min) / ≤ min(14t, 200 mm) (max)
  • p₂ ≥ 2.4 d₀ (min) / ≤ min(14t, 200 mm) (max)

Connection resistance

Governing resistance per bolt is the smaller of the two checks: FRd = min(Fv,Rd, Fb,Rd).

For the whole connection (equal load sharing assumed): n · FRd ≥ VEd, with utilisation η = VEd / (n · FRd).

γM2 = 1.25 (EN 1993-1-8 §2.2). This is a Category A (bearing-type) check assuming the bolts share the load equally.