Topaz Electric 644S EMT Set Screw Coupling, Steel, 1-1/4 inch:

Specifications

• Model Number: 644S
• Trade Size: 1-1/4 inch
• Material: Zinc-plated steel
• Length: 3.25 inches
• Diameter: 1.69 inches
• Connection Type: Set screw
• Certifications:
  • UL Listed (UL 514B)
  • CSA Certified
  • NEMA FB-1 Compliant
  • Federal Specification: W-F-408E 

Key Features

• Set Screw Design: Secures two lengths of EMT conduit without threading.
• Steel Construction: Durable and corrosion-resistant with zinc plating.
• Concrete-Tight When Taped: Suitable for embedment in concrete.
• Versatile Screw Heads: Compatible with slotted, Phillips, and Robertson drivers.
• Rigid/EMT Compatibility: Works with both EMT and rigid conduit types 

Applications

• Joining EMT conduit sections in electrical raceways.
• Dry and concrete-tight installations in residential, commercial, and industrial settings.
• Indoor conduit runs where secure mechanical connection is needed.
• Retrofits and upgrades requiring quick, tool-based assembly.