Foundation bolts manufacturer India — anchor bolts and holding down bolts for structural steel

Foundation bolts — also called anchor bolts or holding down bolts — are the connection between the steel superstructure and the concrete foundation. They are often an afterthought in project procurement, ordered late and on the critical path, but getting the foundation bolt specification wrong can delay the entire steel erection programme. Wrong diameter, wrong projection length, wrong thread specification, or wrong bolt group geometry means the base plates cannot be installed, and the erection crane waits. Suncorporation manufactures foundation bolts for structural steel projects across India, with fast turnaround and the correct documentation.

Foundation bolts manufacturer India — types and configurations

Foundation bolts for structural steel in India come in several configurations depending on the base plate design and the holding-down force required. The most common types in Indian structural steel practice are:

L-bolt (hook bolt) — a straight threaded rod with a 90-degree hook at the bottom, cast into the concrete foundation. The hook provides the mechanical key that resists upward pull-out. L-bolts are used for light to medium column bases where the tension force from wind or seismic loading is modest. The hook length and the embedment depth are designed for the required pull-out resistance.

J-bolt — similar to the L-bolt but with a curved rather than sharp hook at the bottom. J-bolts are used in the same applications as L-bolts and are slightly easier to form consistently because the curved hook does not have a sharp corner that can crack during bending.

Straight rod with nut and washer — a straight threaded rod installed in a pre-drilled hole in the hardened concrete and fixed with a chemical anchor adhesive, or cast into the concrete with a bearing plate at the bottom. Used for post-installed foundation bolt applications where the concrete is already cast before the bolt positions are finalised, and for cases where the pull-out resistance needs to be provided by the adhesive bond rather than a mechanical hook.

Double-ended stud — a bolt threaded at both ends, with a nut and washer assembly at the bottom end that bears against the underside of the base plate or against a washer plate cast into the concrete. Used for heavy column bases where the tension force is high and the base plate design requires a bolt that can be stressed from both above and below the base plate.

Anchor bolt cage assembly — a fabricated assembly of foundation bolts, template plate, and spacer angles, all welded or bolted together to maintain the precise bolt positions during concrete pouring. The cage is positioned in the formwork, the concrete is poured around it, and the template plate is removed after the concrete has cured to leave the bolt tops projecting at the correct height and position. Suncorporation manufactures complete anchor bolt cage assemblies for column bases in structural steel buildings, ensuring the bolt group geometry matches the base plate to within ±2mm.

Foundation bolt materials and IS standards

Foundation bolts for structural steel in India are typically manufactured from IS 1367 property class 4.6 or 5.6 steel rod for standard applications, and from IS 1367 class 8.8 high-strength steel for heavily loaded column bases where the base plate design requires high-strength holding-down bolts. The material specification needs to be confirmed by the structural engineer — using a lower strength bolt than the design requires will result in a base plate connection that cannot develop the design tension capacity.

IS 1367 — the Indian standard for technical supply conditions for threaded steel fasteners — specifies the material properties, dimensional tolerances, and testing requirements for foundation bolts and structural fasteners in India. Suncorporation manufactures foundation bolts to IS 1367 and supplies mill test certificates for the rod material used in each batch.

Hot-dip galvanising of foundation bolts — to IS 1573 — is specified for foundations in corrosive ground conditions or where the exposed bolt thread above the base plate will be in an aggressive atmospheric environment. Galvanised bolts need to be ordered with the correct oversize thread tolerance to allow the nut to run freely on the galvanised thread, which is slightly thicker than an uncoated thread. Suncorporation supplies galvanised foundation bolts with the correct thread tolerancing as standard.

Foundation bolt sizes manufactured by Suncorporation

Suncorporation manufactures foundation bolts from M16 to M64 diameter in standard metric coarse thread, and in UNC or BSW threads on request for projects with legacy bolt specifications. Standard bolt lengths — the dimension from the bottom of the hook to the top of the thread — run from 300mm to 2,500mm, with custom lengths available for deep foundation applications or tall base plates. Projection length above the grout or levelling plate — the free thread length for the nut and washer — is specified by the structural engineer or taken from the base plate design drawing.

Foundation bolts cost and lead time in India — 2026

Foundation bolt manufacturing costs in India in 2026 are approximately Rs 90 to Rs 180 per kg for standard L-bolt and J-bolt assemblies in IS 1367 class 4.6 or 5.6 material, depending on bolt diameter and length. High-strength class 8.8 foundation bolts cost Rs 150 to Rs 250 per kg due to the higher material cost and the additional testing required. Hot-dip galvanised foundation bolts add Rs 18,000 to Rs 25,000 per MT to the base fabrication cost. Anchor bolt cage assemblies — the complete template and bolt group — are quoted on a project basis and typically cost Rs 120 to Rs 220 per kg of the complete assembly.

Lead time for standard foundation bolt orders at Suncorporation is 7 to 14 days for quantities under 500 kg, and 14 to 21 days for larger orders. Rush orders for site-critical foundation bolts can be accommodated in 3 to 5 days for standard sizes and materials. We respond to all foundation bolt enquiries within 24 hours.

Contact Suncorporation for foundation bolts. Also see: Plate fabrication | Industrial shed fabrication | Structural steel Hyderabad