Rebar Dia	Coupler OD	Coupler Length	No. of Shear Bolts	Approx. Weight
16 mm	32 mm	120-150 mm	4 (2+2)	0.8 kg
20 mm	40-45 mm	150-160 mm	6 (3+3)	1.2 kg
25 mm	50 mm	180-200 mm	6 (3+3)	1.9 kg
32 mm	60-62 mm	220-250 mm	8 (4+4)	3.5 kg
40 mm	75 mm	280-300 mm	10 (5+5)	5.8 kg

Thread Information

Thread Type: Not Applicable

The MBT Coupler is a threadless mechanical coupler. Unlike parallel or tapered threaded couplers, the reinforcement bar ends do not need to be threaded before installation.

Connection Method:
Mechanical gripping using serrated saddles and shear bolts.

IS 16172:2023 Test Requirements for MBT

IS 16172 was revised in 2023. MBT falls under Bolted Mechanical Splice.

MBT Couplers used in bridge construction are generally tested according to IS 16172:2014 Mechanical Splices and same in 2023 edition.

Tests you must pass to claim IS 16172 compliance:

1. Static Tensile Test: Must achieve 125% of the rebar's specified yield strength. Failure must be Bar Break outside coupler zone, not in coupler or bolts. Also noted as Must reach 125% of the rebar's specified yield strength.

2. Slip Test: Relative movement between bar and coupler must not exceed 0.10 mm under service loads. As per IS 16172:2023 clause 9.3: Ls 0.10mm for coupler 100mm, Ls 0.20mm for coupler 300mm.

3. Disengagement Test: No thread slip or pull-out under load.

4. Low Cycle & High Cycle Fatigue: For seismic zones. As per IS 16172, Class H couplers meet both low cycle and high cycle fatigue test requirements, while Class L meets only low cycle.

5. Elongation: Minimum 3% elongation before failure of test piece at splice zone.

For your manufacturing file, you need third-party NABL lab report covering all above + chemical test of EN8D.

Standards

Primary Standard

IS 16172:2023 Reinforcement Couplers for Mechanical Splices of Steel Bars in Concrete

BIS's product manual confirms IS 16172:2023 as the current standard and includes Shear Bolting among the recognized reinforcement-coupler types.

Related Standards

Where applicable to the project/product cert.

Advantages of MBT Couplers

• Fast Installation: No threading or bar rotation required, significantly speeding up the splicing process.

• Reliable Quality Check: The shear-off bolt heads provide an instant, visual verification that each connection has been tightened correctly.

• Versatile: Works well in congested areas, for vertical column splicing, and in closure pours where bars cannot be moved.

• Reduces Material Waste: Eliminates the need for lap lengths, saving steel and reducing rebar congestion.

• Corrosion Resistance: Available in stainless steel or with galvanized/epoxy coatings for harsh environments.