MBT Coupler - Bolted Coupler - Threadless Shear Bolt Type for TMT Bars 12mm to 40mm - IS 16172

Product Details

What is MBT Coupler?
MBT Coupler means Mechanical Bolted Type Coupler. It is a threadless mechanical splicing system for joining two reinforcement bars without any bar end preparation. Unlike parallel threaded couplers, it does NOT require a rebar threading rolling machine, forging or welding.

It is also called Shear Bolt Coupler, Bolt-Lock Coupler, Threadless Coupler.

How it Works?
The coupler body contains two serrated saddles inside. Rebars are inserted from both ends. When high-tensile lock shear bolts are tightened with a torque wrench, the bolts embed into the rebar and the saddles bite into both the bar and the shell of the coupler. Installation is complete when heads of all bolts shear off - this gives instant visual proof of correct torque.

Technical Specification:

• Type: ET Series - Same Diameter, Transition available on request
• Sizes: 12mm, 16mm, 20mm, 25mm, 28mm, 32mm, 36mm, 40mm
• Body Material: EN8D Carbon Steel / High Strength Alloy Steel Grade 8.8 / 10.9 - Tensile 650 MPa
• Saddles: Serrated hardened steel
• Bolts: Case-hardened Lock Shear Bolts, break-off type
• Outer Dia x Length: 12mm-110x30mm, 16mm-110x34mm, 20mm-120x38mm, 25mm-125x43mm, 32mm-170x52mm, 40mm-200x62mm
• No. of Bolts: 12mm-2, 16mm-3, 20mm-3, 25mm-4, 32mm-6, 40mm-8 Bolts
• Tool Required: Ratchet wrench for upto 20mm, Nut Runner for 25mm to 40mm. Do not use impact tools.
• Strength: Achieves >115% of characteristic yield strength of Fe500 Grade, failure in bar - outside coupler
• Suitable Bars: Ribbed, Deformed, Plain Round, Imperial, TMT Fe500 / Fe500D / Fe550 / Fe600
• Finish: Black Oxide / Self Colour / Hot Dipped Galvanized for coastal areas
• Standards: IS 16172:2023, IS 456, IS 13920, BS 8110, ACI 318 Type 1 & Type 2, ISO 15835
• Tests: Static Tensile, Slip Test <0.10mm, Low Cycle Fatigue

Key Features & Advantages:

1. No Bar End Preparation: No threading, no forging, no welding, no bar rotation needed.
2. Best for Retrofit: Ideal when one bar is already concreted and cannot rotate - column extension, raft to column, beam extension.
3. Fast & Visual Check: 2-3 minutes per joint. Bolt head shears off at correct torque - any labour can verify.
4. Works in Confined Space: No machine needed at joint, works where threading machine cannot reach.
5. Saves Steel: Eliminates lap length - saves 10-15% steel in 25mm, 32mm, 40mm dia.
6. No Congestion: Allows proper concrete flow, no honeycombing.

MBT vs Parallel Threaded Coupler:
Parallel Threaded needs threading machine + forging + skilled operator but per piece cost is lower. MBT per piece cost is higher but NO machine cost, best for repair sites, small qty, and where threading is not possible.

Installation Steps:

1. Select correct coupler size for rebar dia.
2. Insert first rebar to centre mark inside coupler.
3. Insert second rebar from other side.
4. Tighten bolts sequentially from centre outwards with torque wrench till all heads shear off.
5. Done.

Applications:
High-rise columns, raft foundations, pile cages, retrofitting & repair, bridge piers, metro projects, precast joints, foundation bolts, starter bar extension.

HS Code: 73269099 - Other Articles of Iron & Steel (Coupler), 82077000 - Thread Rolling Tools