1. What is Bolt Pull Out Strength?

The bolt pull out strength is the force required to pull a bolt out of the material it's embedded in. It depends on the bolt's diameter, embedded length, and the material's shear strength.

2. How Does the Calculator Work?

The calculator uses the bolt pull out strength formula:

Where:

• \( F \) — Pull out force (N)
• \( d \) — Bolt diameter (mm)
• \( L \) — Embedded length (mm)
• \( S \) — Material shear strength (MPa)
• \( \pi \) — Pi constant (~3.1416)

Explanation: The formula calculates the shear area (π×d×L) and multiplies it by the material's shear strength to determine the maximum force before failure.

3. Importance of Pull Out Strength Calculation

Details: Calculating pull out strength is crucial for structural integrity in construction, mechanical design, and engineering applications to ensure fasteners can withstand expected loads.

4. Using the Calculator

Tips: Enter bolt diameter in mm, embedded length in mm, and material shear strength in MPa. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What affects bolt pull out strength?
A: Main factors are diameter, embedded length, material shear strength, thread engagement, and installation quality.

Q2: How accurate is this calculation?
A: It provides a theoretical maximum. Real-world values may vary due to material imperfections, installation factors, and dynamic loads.

Q3: What's typical shear strength for common materials?
A: Concrete: 1-4 MPa, Steel: 200-400 MPa, Wood: 5-15 MPa (parallel to grain).

Q4: Should safety factors be applied?
A: Yes, typical safety factors range from 2-5 depending on application criticality and load characteristics.

Q5: Does thread type affect pull out strength?
A: Yes, coarse threads generally have higher pull out strength in softer materials, while fine threads perform better in hard materials.