Are Unbrako structural bolts approved for Indian government projects?

Yes. Unbrako IS 3757 structural bolts are manufactured to Indian Standards and carry NABL ISO/IEC 17025 accredited test certificates. They comply with IS 4000 (Code of Practice for Assembly of Structural Joints using HSFG Bolts) and are accepted by all major Indian construction authorities including NHAI and railway boards.

Where can I buy Unbrako structural fasteners in Noida?

Shri Narayan Machinery LLP in Sector 9, Noida supplies the complete Unbrako structural fastener range including IS 3757 bolts, TC bolts, structural nuts, washers, anchors, and rebar couplers. Call +91-9811104037 for project quotations and material test certificates.

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Structural & Construction Fasteners: Unbrako IS 3757 / CE Approved

Name: Structural & Construction Fasteners: Unbrako IS 3757 / CE Approved
Brand: Unbrako

The sheared-off spline on a TC bolt is your inspection record: Unbrako tension control structural bolts (M12 to M36, Class 10.9) snap their splined end at a calibrated preload, so every joint reaches correct tension without a torque wrench. For conventional HSFG joints, the IS 3757 structural bolt range covers M16 to M30 with matching IS 6623 nuts and IS 6649 hardened washers, assembled per IS 4000 and accepted by NHAI and railway authorities. Drop-in anchors (M6-M20) handle concrete fixing, and rebar couplers splice 12mm to 40mm reinforcement mechanically. Everything is CE approved, tested in a NABL ISO/IEC 17025 lab, and shipped with material test certificates. PEB erectors and metro contractors across NCR source project quantities from us. Stocked at Sector 9, Noida; WhatsApp your bolt list for price.

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Structural Bolt Standard: IS 3757 (High Strength Structural Bolts)Structural Nut Standard: IS 6623Structural Washer Standard: IS 6649TC Bolt Size Range: M12, M16, M20, M22, M24, M27, M30, M36

Key Features

IS 3757 High Strength Structural Bolts, M16 to M30 for steel structures

CE Approved for international structural steel projects

Tension Control (TC) Bolts, M12 to M36, splined end shears at calibrated preload

No torque wrench needed for TC bolts, preload guaranteed by shear-off design

Matching IS 6623 Structural Nuts and IS 6649 Structural Washers

Drop In Anchors for concrete-to-steel connections

Rebar Couplers for reinforcement bar mechanical splicing

NABL ISO/IEC 17025 certified testing with full material test certificates (MTCs)

Hot Dip Galvanized finish available for outdoor/corrosive environments

Manufactured to Indian Standards (IS) for domestic infrastructure projects

Technical Specifications

Structural Bolt Standard	IS 3757 (High Strength Structural Bolts)
Structural Nut Standard	IS 6623
Structural Washer Standard	IS 6649
TC Bolt Size Range	M12, M16, M20, M22, M24, M27, M30, M36
Structural Bolt Size Range	M16, M20, M22, M24, M27, M30
Property Class	8.8 / 10.9 (application dependent)
Material	Medium Carbon Steel / Alloy Steel, Quenched & Tempered
Finish Options	Black Oxide, Hot Dip Galvanized (IS 1367 Part 13 / ISO 10684)
Certification	CE Marking, NABL ISO/IEC 17025 test certificates
Additional Products	Drop In Anchors, Rebar Couplers

Applications

The Structural & Construction Fasteners is used across a wide range of industrial applications:

Steel structure connections, beam-to-column, beam-to-beam, splice plates
Pre-engineered buildings (PEB), primary and secondary steel framing
Bridge construction, girder connections, bearing assemblies, deck fastening
Metro rail infrastructure, viaduct steelwork, station structures
Flyovers and elevated corridors, structural steel connections
Industrial sheds and warehouses, truss connections, purlin bolting
Transmission towers and telecom structures, leg and bracing joints
Concrete anchoring, base plate fixing, equipment foundation bolting

Industries Served

Construction & BuildingInfrastructure & HighwaysMetro Rail & RailwaysPre-Engineered BuildingsBridge & Flyover ConstructionIndustrial Sheds & WarehousesPower Transmission TowersOil & Gas Infrastructure

Need Structural & Construction Fasteners? Get the Best Dealer Price

As your Unbrako dealer, Shri Narayan Machinery LLP offers competitive pricing on the full Structural & Construction Fasteners range. Call us for availability and your best quote.

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C-101, Sector 9, Noida, Uttar Pradesh 201301 | Unbrako Dealer

Frequently Asked Questions: Structural & Construction Fasteners

A Tension Control bolt has a splined extension beyond the nut end. During installation, a special TC wrench grips both the spline and the nut. As the nut is tightened, the spline shears off at a precisely calibrated torque, guaranteeing the correct bolt preload without a separate torque wrench. The sheared spline is visual proof that the bolt is correctly tensioned.

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