GI Wire for Construction — Binding Wire Selection Guide for Contractors

GI Binding Wire for Construction — A Practical Selection Guide

On civil construction sites, reinforcing steel bars (rebars) must be tied securely together to form columns, beams, slabs, and footings before concrete is poured. The wire used to secure these rebars is called binding wire. In India, galvanized iron (GI) binding wire is increasingly preferred over black annealed wire due to its rust resistance, preventing concrete spalling. This guide explains how to select the right wire for your project.

Common Wire Gauges for Concrete Binding

Standard Gauge (SWG)	Diameter (mm)	Typical Application
16 SWG	1.60 mm	Heavy structural rebar binding (foundation mats, column cages)
18 SWG	1.20 mm	Standard slab and beam rebar binding (most common gauge)
20 SWG	0.90 mm	Light binding, mesh tying, stirrup positioning

Soft Annealed Grade: The Non-Negotiable Standard

Construction binding wire must strictly be of a soft annealed grade (tensile strength below 450 N/mm²). Hard grade wire cannot be easily twisted by hand or tying tools, leading to loose joints that slip during concrete pouring. Soft wire bends easily and locks rebars rigidly in place.

Estimated Requirement: How Much to Order?

A common rule of thumb for construction estimation is that you will need approximately 8 kg to 10 kg of binding wire per metric ton (MT) of reinforcement steel. Factors like rebar spacing and thickness will cause minor variations.