Structural Bolt Grip Guide

How Grip is Calculated

The "Grip" is defined as the total thickness of all material being connected (steel plies + washers). To determine the ordering length, we follow standard steel detailing practices:

• Grip: Total thickness of steel + thickness of all washers (F436).
• Nut Allowance: The height of an AISC Heavy Hex Nut (varies by diameter).
• Stick-out: A safety allowance (typically 1/4" to 1/2") to ensure full thread engagement.

Rounding Standards

Structural bolts are not ordered in exact decimals. This tool applies "Smart Rounding" logic used by most fabricators:

• Up to 6 inches: Rounds to the nearest 1/4" increment (e.g., 4.25", 4.50").
• Over 6 inches: Rounds to the nearest 1/2" increment. Longer bolts are typically stocked in 1/2" steps to reduce inventory complexity.