Bolt Pitch Distance Requirement in IS 800:2007

The question asks for the minimum pitch distance required for bolts in structural steel connections, as specified by the Indian Standard code IS 800:2007, based on the bolt diameter denoted as d.

Understanding Minimum Pitch Distance

In structural steel design, the pitch is the distance between the centres of adjacent bolts, measured parallel to the direction of the load or stress application. Ensuring adequate pitch is crucial for several reasons:

• It prevents the steel material between the bolt holes from becoming too weak.
• It ensures proper load distribution among the bolts.
• It facilitates efficient use of the connected members.

IS 800:2007 Specification

According to Clause 6.2.2 of IS 800:2007 (Code of Practice for General Construction in Steel, Rolled, Cold Formed Structurally Shaped Sections), the minimum pitch of bolts is specified to maintain the structural integrity of the connection.

The code mandates that the minimum pitch distance between the centres of adjacent bolts shall be 2.5 times the nominal diameter of the bolt, where the diameter is represented by d.

Mathematically, this requirement is expressed as:

Where:

• $ P_{\text{min}} $ = Minimum pitch distance
• $ d $ = Nominal diameter of the bolt

Analysis of Options

Based on the IS 800:2007 specification:

• 2.5d: This matches the minimum requirement stated in the code.
• 2d: This value is less than the specified minimum.
• 1.7d: This value is also less than the specified minimum.
• d: This value is significantly less than the required minimum pitch.

Conclusion

Therefore, the minimum pitch distance required for a bolt with diameter d, as per IS 800:2007, is 2.5d.