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BIS Certified Rebar Coupler Manufacturer

BIS Certified Rebar Coupler Manufacturer Specification

Prop Head
Standard Head

Features
High Strength, Reliable Rebar Connection, Easy Installation, Quality Tested

Color
Metallic Grey / Black

Technique
Forged

Weight
869 Grams (g)

Constitute
Standard

Pin
Other

Product Type
Other

Material
Steel

Components
Couplers

Diameter
12 mm, 16 mm, 20 mm, 25 mm, 32 mm, 40 mm Millimeter (mm)

Length
12 mm, 16 mm, 20 mm, 25 mm, 32 mm, 40 mm Millimeter (mm)

Height
12 Millimeter (mm)

Thickness
2.5 Inch

Surface Treatment
Powder Coating

Application
Construction

Size
12 mm to 40 mm

BIS Certified Rebar Coupler Manufacturer Trade Information

Minimum Order Quantity
10 Pieces

Delivery Time
24 Hours

About BIS Certified Rebar Coupler Manufacturer

BIS Certified Rebar Coupler

A BIS Certified Rebar Coupler is an ISI-Marked mechanical splice device used to join two reinforcement bars (TMT bars) end-to-end, manufactured and tested as per Indian Standard IS 16172 : 2014 - Reinforcement Couplers for Mechanical Splices of Bars for Concrete Reinforcement - Specification.

It is the only type of coupler legally accepted for Government, PWD, CPWD, NHAI, Metro, Railways, Nuclear and High-rise projects in India where mechanical splicing is specified.

Why BIS Certification is Required?

Normal locally-made couplers have no guarantee of strength, thread accuracy, steel quality or slip performance. A BIS Certified coupler guarantees:

Raw material is traceable - High tensile seamless steel, not scrap / MS pipe
Strength > Parent Bar - Joint will not fail before the bar itself
Slip < Permissible limit - Joint will not elongate under load
Seismic Safe - Suitable for Earthquake Zones III, IV, V as per IS 13920:2016
Third Party Audited - Factory inspected by BIS, samples tested in BIS / NABL lab, Licence
ISI Mark on every piece - Full traceability

Relevant codes:

IS 16172:2014 (Reaffirmed): Main specification for coupler
IS 1786:2008: High strength deformed TMT bars Fe415, Fe500, Fe500D, Fe550, Fe550D, Fe600
IS 456:2000 Cl. 26.2.5: Allows mechanical splices as alternative to lap
IS 13920:2016: Ductile detailing - In seismic zones, lap not allowed in plastic hinge zones, only Type-2 mechanical splice allowed
IRC 112, MoRTH Sec. 1600: For bridges

The BIS Standard: IS 17840

The Indian Standard IS 17840 governs mechanical splices. Key testing requirements under this standard include:

Tensile Strength Test: The spliced bar must not break at the joint; it must achieve a strength equal to or greater than the actual yield strength of the rebar.
Slip Test: Under loading, the slip (linear displacement) between the bar and the coupler must be within strictly defined limits (usually less than 0.1 mm) to ensure the joint does not loosen under cyclic loads.
Cyclic Loading Test: The coupler must withstand repeated loading and unloading (simulating seismic activity or wind loads) without failure or excessive slip.
Fatigue Test: Ensures the joint can endure long-term dynamic stresses.

Types of BIS Certified Couplers

All types are covered under IS 16172, but most common BIS licence is for Parallel Thread Rolled Coupler.

1. Standard Parallel Thread Coupler (Roller / Cold-Rolled) - Most Used
Bar end is rib-peeled and cold-rolled to form parallel threads. Coupler with internal parallel threads connects both bars. For 16mm to 40mm. No bar diameter reduction, no weakening.

2. Taper Threaded Coupler
Tapered threads for easy alignment. Older technology, less common now.

3. Upset / Hot Forged Enlarged End Coupler
Bar end is upset (enlarged by forging) then threaded. Core diameter increases, best for 32mm to 50mm heavy bars, nuclear / bridges.

4. Transition / Reducer Coupler
To join two different diameters e.g. 25mm to 20mm, 32mm to 25mm.

5. Position Coupler ( Bolt + Locknut )
When both bars cannot be rotated - e.g. joining to existing column, beam-column junction, precast segment. One side is extended thread with locknut.

6. Weldable / End-Anchor Coupler
One end threaded, other end welded to plate / structural steel. Used as end anchorage instead of 90-degree bend.

7. Headed Bar Coupler
Acts as anchor head to replace development length / bent hooks in congested pile caps, footings.

Raw Material and Manufacturing Process

A genuine BIS coupler is NOT cut from pipe.

Material: High-tensile carbon / alloy steel bars - Grades like C45, EN8D, 16MnCr5, IS 2062 E350 or equivalent. Min. UTS 600-700 N/mm2, higher than TMT bar.

Process in BIS factory:

Cut seamless round bar to length
CNC drilling + chamfering + internal threading with gauges
100% Go / No-Go thread gauge checking
Rust preventive oil coating + plastic caps
Laser / Punch marking: Size, Brand, IS 16172, ISI Logo, CM/L No., Batch No.
Batch testing: Tensile, Slip, Dimensional, Chemical

Outer Diameter is normally ~1.45 to 1.6 x bar dia. Length is ~2D + 10-15mm.

Typical dimensions:

Bar Dia	Coupler OD (approx)	Coupler Length (approx)	Tightening Torque
16 mm	24-26 mm	48-50 mm	100-120 Nm
20 mm	29-31 mm	56-60 mm	160-180 Nm
25 mm	37-39 mm	66-72 mm	220-250 Nm
28 mm	41-43 mm	74-80 mm	260-280 Nm
32 mm	47-49 mm	84-90 mm	300-340 Nm
36 mm	52-55 mm	95-100 mm	360-400 Nm
40 mm	59-62 mm	105-110 mm	400-450 Nm

Technical Requirements as per IS 16172:2014

A lot must pass all these to get ISI Mark:

a) Visual & Dimensional: No cracks, pits, damaged threads. Thread profile checked with Go / No-Go gauges.

b) Chemical Composition: C, S, P, Sulphur & Phosphorus within limits, Carbon Equivalent (CE) controlled for weldability.

c) Static Tensile Test (Most Important):
The coupler + 2 bars assembly is pulled in UTM to failure.
Acceptance: Ultimate tensile strength shall not be less than the actual UTS of the parent unspliced bar, and in no case less than the specified characteristic UTS of the grade (e.g. > 565 MPa for Fe500D). Failure shall occur outside the coupler zone / in the parent bar. In practice, good BIS couplers achieve 125% of yield (Type-2 splice as per ACI 318).

d) Slip Test:
After loading to 70% of specified yield strength, measured permanent slip between bar and coupler shall be < 0.10 mm. This ensures no cracking in concrete.

e) Cyclic / Fatigue Test for Seismic:
For structures in Seismic Zone III and above, couplers are subjected to high-cycle and low-cycle reversed loading. No failure / excessive slip allowed.

f) Splice Performance Grade:
Manufacturers declare couplers suitable for Fe500D, Fe550D up to specified bar elongation (minimum 12-16%).

Sampling at site as per standard practice: 2 specimens per 500 couplers per dia / per lot sent to NABL lab for tensile + slip test before mass use.

Installation Methodology at Site

BIS certification is for coupler body, but joint strength depends 100% on correct bar threading.

Bar Cutting: Cut bar at 90 degrees with chop saw, not gas cutter.
Rib Peeling: Peel ribs for length = half coupler + 2-3 threads using rib-peeling machine.
Cold Rolling: Cold-roll parallel threads using approved threading machine. No material removal, grain flow is strengthened.
Checking: Check with Go/No-Go ring gauge. Go should pass fully, No-Go should not pass more than 2 turns.
Protection: Put plastic cap immediately to protect threads from dust/rust.
Joining: Screw bars into coupler manually, then tighten with torque wrench / pipe wrench to specified torque. There should be zero exposed threads (max 3-4 mm tolerance / half thread).
Staggering: As per IS 456 / IS 13920, mechanical splices should be staggered - not more than 50% bars spliced at one section in columns, maintain clear spacing >25mm for concrete flow.

Entire threading must be done by supplier-trained operator. Reputed suppliers give machine on rent + operator + gauge free with coupler supply.

Advantages Over Lapping

Saves 20-30% Steel: No lap length (50D) and no wastage. For 32mm bar, lap = 1.6m saved per joint.
Reduces Congestion: Especially in columns, shear walls, pile caps, beam-column joints. Concrete can flow easily, better honeycomb-free concreting.
Load Path Continuity: Lap transfers load via concrete bond, coupler transfers steel-to-steel. Better for seismic, cyclic, fatigue loads.
Faster Construction: No extra shutter size for lapped bars, easy shuttering, easy for precast and higher lifts.
Eco-friendly & Cost Saving: Despite coupler cost Rs. 40 to Rs. 180/pc depending on dia, net saving after steel + labour saving is 15-25% in large dia >20mm.
Mandatory for >36mm: Lapping of 36mm and 40mm bars is practically not allowed due to congestion - couplers are the only solution.

Lap vs Coupler:

Parameter	Lap Splice (50D)	BIS Coupler Splice
Steel consumption	High	Low, saves 2-5 kg per joint
Congestion	Very high	Single bar line
Seismic performance	Poor, bond failure	Excellent, Type-2
Quality control	Visual only	Measurable torque + lab test
Cost for 16mm	Cheaper	Costly
Cost for 25mm+	Costly	Cheaper overall

Thumb rule in India: Use couplers for 20mm dia and above. Continue lapping for 8,10,12,16mm unless congestion is high.

Where It Is Used?

High-rise towers, metro piers, bridges, dams, power plants, refineries, pile foundations, diaphragm walls, precast connections, radiation-shield structures, industrial heavy foundations, retaining walls.