Anchor Bolts Manufacturer in India | Wedge & Expansion Anchor Bolts

Overview

Wedge & Expansion Anchor Bolts: Manufacturer & Exporter

An anchor bolt fixes steelwork, machines and equipment to concrete. The wedge anchor in the photo is the most common post-installed type. You drill a hole, push the anchor through the part being fixed, and tighten the nut. The cone pulls into the clip and locks the anchor in the hole.

Exotic Alloy manufactures anchor bolts in Mumbai, India. We supply contractors, fabricators, racking and solar installers and MEP firms across India, and export to Indonesia, the Gulf, Africa and Europe. Studs are cold formed with rolled threads. Clips are pressed from spring-tempered strip, and every anchor is packed with its nut and washer, ready to set.

Why a wedge anchor?

It goes in after the concrete has cured, through the fixture, with ordinary tools. It takes load as soon as it is torqued, with no curing time as with resin, and holds with a far stronger grip than a plastic plug.

M6 – M24 Through-fixing A4 / A2 stainless Zinc & HDG steel Sleeve & drop-in

Wedge anchor at a glance

Holds by: Expansion clip forced out by a cone
Drill bit: Same as anchor size (M12 → 12 mm)
Base: Hardened concrete, C20/25 to C50/60
Design: EN 1992-4 / ACI 318 Ch. 17 with ETA or ICC-ES data
Material: A4, A2 stainless; zinc plated, HDG steel
Related: J bolts (cast-in), U bolts, hex bolts

Parts of an M12 × 100 wedge anchor, drawn to scale; clip and cone proportions vary between makes. The nut and washer come assembled. The clip is held loosely on the reduced neck until the nut is tightened.

Specification

Anchor Bolt Specification

The range we manufacture and supply.

ProductsWedge (through bolt) anchors; sleeve anchors; drop-in anchors; studs for chemical anchors; anchors to customer drawing

Size rangeM6, M8, M10, M12, M16, M20, M24; lengths to suit the embedment plus fixture thickness

ThreadMetric coarse, rolled, 6g; nut ISO 4032; washer ISO 7089 or large-diameter washer

MaterialsStainless A4 (1.4401 / 1.4404 / 1.4571), A2 (1.4301), HCR 1.4529; carbon steel

FinishPassivated stainless; zinc plated ≥ 5 µm (ISO 4042); hot-dip galvanized (ISO 10684)

Base materialNormal-weight concrete C20/25 to C50/60, cracked or non-cracked as allowed by the anchor’s assessment

Design & approvalDesign to EN 1992-4 or ACI 318 Chapter 17 using values from an ETA (EAD 330232) or ICC-ES report (AC193 / ACI 355.2)

MarkingSize, length code and material (e.g. A4) on the stud end; embedment mark on request

CertificationMill certificate; EN 10204 3.1 with material, dimensions and coating; PMI for stainless

PackingBoxes of 25 / 50 / 100 assembled anchors, bulk cartons, or private-label packs

Types

Types of Anchor Bolts

How each type holds in the concrete, and when to use it.

Five anchor types in section (schematic). The first three hold by expansion in a drilled hole, the chemical anchor by bond to resin, and the cast-in bolt by its head. See J bolts for cast-in hooked anchors.

Type	How it holds	Load	Cracked concrete	Typical use
Wedge anchor	Cone expands a clip as the nut is torqued	Medium to high	Only versions assessed for it	Steel columns, racking, machinery, handrails
Sleeve anchor	Split sleeve expands along its length	Light to medium	Usually non-cracked only	Fixtures in concrete and solid masonry
Drop-in anchor	Internally threaded shell expanded with a setting tool	Light	Mainly multiple-point, redundant fixings	Pipe and cable tray hangers, threaded rod
Chemical anchor	Threaded rod bonded in resin	High, close to edges	With systems assessed for it	Heavy loads, small edge distances, rebar
Cast-in anchor bolt	Head or hook embedded during the pour	Highest	Yes	Column base plates and foundations

Stainless Wedge Anchors

A4 (316) · A2 (304) · M6 – M24

Outdoor, coastal and wet locations: facades, balustrades, solar frames, marinas.

Zinc Plated & HDG Wedge Anchors

Carbon steel · ISO 4042 / ISO 10684

Warehouses, racking and dry interiors (zinc plated); mild outdoor exposure (galvanized).

Sleeve Anchors

Hex nut, hex bolt or countersunk head

Medium-duty fixing in concrete and solid brick, with hole tolerance taken up by the sleeve.

Drop-in Anchors

M6 – M20 internal thread

Flush with the soffit, ready for threaded rod hangers; supplied with setting tools.

Sizes

Wedge Anchor Sizes & Setting Data

Size	Drill bit d₀ mm	Stress area A_s mm²	Steel N_Rk,s 5.8 kN	Steel N_Rk,s 8.8 kN	Steel N_Rk,s A4-70 kN	Spanner ISO 4032, mm	Washer ISO 7089, mm
M6	6	20.1	10.1	16.1	14.1	10	12 × 1.6
M8	8	36.6	18.3	29.3	25.6	13	16 × 1.6
M10	10	58	29.0	46.4	40.6	16	20 × 2
M12	12	84.3	42.1	67.4	59.0	18	24 × 2.5
M16	16	157	78.5	125.6	109.9	24	30 × 3
M20	20	245	122.5	196.0	171.5	30	37 × 3
M24	24	353	176.5	282.4	247.1	36	44 × 4

Steel N_Rk,s = stress area × minimum tensile strength of the thread (our calculation); an anchor can fail at its neck first, so use the value in its ETA. The fixture hole is usually 1 to 2 mm larger than the anchor; the approval gives the maximum. Typical published installation torques for steel wedge anchors are 20 N·m (M8), 45 N·m (M10) and 60 N·m (M12); for other sizes follow the anchor’s approval.

Installed M12 × 110 wedge anchor (section, schematic, 40 % scale). h₀: hole depth; h_nom: depth of the anchor below the surface; h_ef: effective embedment, which sets the concrete cone capacity; t_fix: fixture thickness. The anchor length must cover h_nom + t_fix + washer + nut.

Installation

How to Install a Wedge Anchor

Four steps (schematic). Through-fixing means the hole is drilled through the positioned fixture, so the holes always line up.

Do

Drill with a hammer drill and a carbide bit of the anchor’s size
Clean the hole: blow, brush, blow
Keep to the minimum edge distance, spacing and member thickness of the approval
Apply the installation torque with a calibrated torque wrench

Don't

Set anchors in fresh concrete, or cut through reinforcement without approval
Use an oversize or worn drill bit: the clip cannot grip
Over-torque: it can split the concrete near edges
Use zinc plated anchors outdoors or in damp concrete

Design

Anchor Bolt Failure Modes & Concrete Capacity

An anchor in tension has four ways to fail. The design resistance is the lowest of them.

Tension failure modes per EN 1992-4 (schematic). Steel and concrete cone resistance can be calculated. Pull-out and splitting depend on the anchor and are taken from its ETA or ICC-ES report.

Concrete cone resistance N⁰_Rk,c of a single anchor

h_ef mm	C20/25 cracked kN	C20/25 uncracked kN	C30/37 cracked kN	C30/37 uncracked kN	c_cr,N = 1.5 h_ef mm	s_cr,N = 3 h_ef mm
40	8.7	12.4	10.7	15.2	60	120
50	12.2	17.4	14.9	21.3	75	150
60	16.0	22.9	19.6	28.0	90	180
70	20.2	28.8	24.7	35.3	105	210
80	24.6	35.2	30.2	43.1	120	240
100	34.4	49.2	42.2	60.2	150	300
125	48.1	68.8	58.9	84.2	187.5	375

Characteristic values for one anchor away from edges and other anchors: N⁰_Rk,c = k₁ √f_ck h_ef^1.5, with k₁ = 7.7 (cracked) or 11.0 (non-cracked) for post-installed anchors (EN 1992-4; our calculation). Divide by γ_Mc = 1.5 × γ_inst for design. ACI 318 uses the same √f′_c h_ef^1.5 form.

Calculator

Anchor Bolt Tension Capacity Calculator (EN 1992-4)

Single anchor in tension: concrete cone failure (including one edge) and steel failure. Use it for preliminary sizing, then check pull-out, splitting and minimum dimensions with the anchor’s ETA.

Anchor & concrete

Size

Anchor steel

Embedment, mm

Edge distance, mm

Concrete

Concrete state

Reinforcement

Installation safety

Use cracked concrete unless the concrete is proven to stay uncracked. Embedment means the effective embedment h_ef. Take γ_inst from the anchor’s ETA. An edge distance of 1.5 h_ef or more means the edge has no effect.

Design tension resistance

15.0

kN N_Rd · concrete cone governs

Cone N⁰_Rk,c:22.5 kN

Cone, design N_Rd,c:15.0 kN

Steel, design N_Rd,s:31.6 kN

Edge & spalling factors:1.00 × 1.00 × 1.00

Materials

Anchor Bolt Materials & Corrosion Protection

An anchor sits in concrete for the life of the building, so choose the material for the exposure.

Material	Grade	EN 1993-1-4 corrosion class	Typical use
Carbon steel, zinc plated	≥ 5 µm zinc (ISO 4042)	—	Dry indoor concrete only
Carbon steel, hot-dip galvanized	ISO 10684	—	Outdoor in mild environments
Stainless A2	1.4301 (304)	CRC II	Indoor and mild outdoor, no chlorides
Stainless A4	1.4401 / 1.4404 / 1.4571 (316 / 316L / 316Ti)	CRC III	Outdoor, coastal and industrial
High corrosion resistant (HCR)	1.4529 (alloy 926)	CRC V	Road tunnels, indoor swimming pools, offshore

Corrosion resistance classes (CRC) from EN 1993-1-4: the higher the class, the more aggressive the environment the steel can withstand.

Carbon steel

Zinc plated · HDG

Cold-heading steels for studs, spring strip for clips.

1010 1022 1035

Stainless A2

1.4301 · CRC II

Indoor and mild outdoor use without chlorides.

304

Stainless A4

1.4401 / 1.4571 · CRC III

The usual choice outdoors, coastal and industrial.

316 316L 316Ti

HCR steel

1.4529 · CRC V

Road tunnels and indoor pools, where A4 can crack.

Alloy 926 2205

Manufacturing

How Our Anchor Bolts Are Made

1

Wire & strip

Stainless or carbon wire for studs; spring strip for clips; certified by heat.

2

Cold forming

Cone and reduced neck formed on multi-station headers.

3

Thread rolling

Metric threads rolled to 6g with the specified thread length.

4

Clip pressing

Clips stamped, rolled and fitted over the cone neck.

5

Finishing

Zinc plating, hot-dip galvanizing or stainless passivation.

6

Assembly

Nut and washer fitted, anchors gauged and boxed by lot.

Applications

Where Our Anchor Bolts Are Used

Steel structures

Column and beam brackets, mezzanines and canopies fixed to slabs and walls.

Racking & storage

Pallet racking base plates in warehouse floors.

Solar & facades

Rooftop solar frames, cladding brackets and balustrades in A4 stainless.

Machinery

Fixing machines, pumps and tanks to plinths and floors.

Infrastructure

Crash barriers, signs, rail fixings and tunnel services (HCR steel).

MEP services

Pipe supports, cable trays and duct hangers with drop-in anchors.

Quality & testing

Anchor Bolt Inspection & Site Testing

Check	Method	Applied to
Stud, cone & neck	Gauges and callipers to drawing	Every lot
Thread	Ring gauges	Every lot
Clip fit	Assembly and slip check on the neck	Every lot
Material	Mill certificate; PMI for stainless	Every heat
Coating	Magnetic thickness gauge	Plated and galvanized lots
Tensile test in concrete	Pull test on set anchors	On request, per lot

Every shipment includes

Mill certificate with heat number
Dimensional and coating report
Lot number on every box

On site

Proof-load testing of installed anchors to BS 8539 can confirm installation quality
Installer records: hole depth, cleaning, torque

FAQ

Anchor Bolt Questions, Answered

A wedge anchor is a post-installed anchor bolt for concrete: a threaded stud with a cone at one end and an expansion clip around it, supplied with a nut and washer. It is pushed through the fixture into a drilled hole, and tightening the nut pulls the cone into the clip, which presses against the hole wall and locks the anchor in the concrete.

Use a drill bit of the same nominal diameter as the anchor: 10 mm for an M10 anchor, 12 mm for an M12 anchor, and so on. Drill deeper than the anchor's embedment so it can be set fully, and clean the dust out of the hole before installing.

Each anchor has its own approved values, but the concrete cone limit can be estimated with EN 1992-4. For example, an M12 anchor with 70 mm effective embedment in cracked C25/30 concrete, away from edges, has a characteristic cone resistance of about 22.5 kN and a design resistance of about 15.0 kN (partial factor 1.5). Pull-out and splitting values come from the anchor's ETA or ICC-ES report, and the lowest value governs.

A cast-in anchor bolt, such as a J bolt or headed bolt, is set in position before the concrete is poured and holds by its hook or head. A wedge anchor is installed later in a drilled hole in hardened concrete and holds by expansion. Wedge anchors let you fix items anywhere after the concrete has cured, without templates set during the pour.

Use the installation torque given in the anchor's approval or datasheet. Typical published values for steel wedge anchors are about 20 N·m for M8, 45 N·m for M10 and 60 N·m for M12. Too little torque leaves the clip unexpanded; too much can split thin members or close to edges.

Zinc plated anchors are for dry indoor concrete only. Use hot-dip galvanized or A4 (316) stainless anchors outdoors and in damp areas, A4 near the coast and in industrial air, and high corrosion resistant 1.4529 steel for road tunnels and indoor swimming pools.

The full concrete cone capacity needs an edge distance of 1.5 times the effective embedment and a spacing of 3 times the embedment (EN 1992-4). Anchors can be closer, down to the minimum values in their approval, but the capacity is reduced. Close to an edge there is also a risk of splitting.

Only wedge anchors assessed for cracked concrete, for example under an ETA option for cracked and non-cracked concrete or an ICC-ES report to ACI 355.2, should be used in tension zones of beams and slabs. Ordinary expansion anchors are for non-cracked concrete only. Cracked concrete also lowers the concrete cone capacity, as shown in the calculator.