Bolted Connection

A bolted connection joins steel members with bolts and is the dominant site connection method because it needs no skilled welding/inspection in the field and allows fast erection. Ordinary (bearing-type) bolts (property classes per IS 1367, e.g. 4.6, 8.8) transfer shear through the bolt shank bearing on the plate; the connection design per IS 800 Cl. 10 checks each bolt for shear capacity and bearing capacity (on the connected plate), the connected plate for net-section and block shear, and bolts in tension where applicable, taking the least.

Proper detailing — minimum/maximum pitch, edge and end distances, number of bolt rows, and avoiding eccentricity — is essential and a common source of errors and rework. High-strength friction-grip (HSFG) bolts (IS 4000) are a distinct slip-critical category that transfers load by friction from a pre-tensioned clamping force, used where slip, fatigue or reversal cannot be tolerated. The choice of bolt type, grade and arrangement is a balance of capacity, fabrication tolerance, fit-up and erection economy.