3.5"-4.5" O.D./I.D. Expander Exhaust Pipe Coupler 7" Length

Transition your exhaust system with industrial precision. This Dynaflex expanding coupler is specifically engineered to bridge the gap between 3.5-inch and 4.5-inch exhaust components. Proudly Made in the U.S.A., it is the professional choice for heavy-duty truck repairs, generator venting, and custom high-flow exhaust fabrication.

Product Overview

Built from rugged 16-gauge carbon steel, this 7-inch adapter is designed to handle the extreme thermal stress and high-vibration environments of diesel engines. The O.D./I.D. configuration provides maximum versatility for adapting smaller turbo outlets or piping to larger stacks and mufflers.

• Configuration: 3.5" O.D. to 4.5" I.D.

• Overall Length: 7.0"

• Material: 16 Gauge (.065") Carbon Steel

• Origin: Proudly Made in the U.S.A.

Key Features

• Precision Expansion: The 4.5" I.D. end is precision-expanded to slip directly over a standard 4.5" O.D. pipe.

• Versatile Connection: The 3.5" O.D. end is sized to slip into a 3.5" I.D. component, making it an ideal "male-to-female" adapter.

• Weld-Ready Steel: Ships in a raw, unfinished state—perfect for fabricators who need a clean surface for high-strength welding without the interference of coatings.

• Extended Length: The 7-inch OAL provides a smooth, gradual transition to maintain exhaust velocity and reduce backpressure.

Specifications Table

Applications

• Turbocharged Systems: Adapting 3.5" turbo downpipes to 4.5" exhaust piping.

• Custom Stacks: Transitioning mid-chassis piping to larger diameter vertical stacks.

• Industrial Power: Connecting commercial generator exhaust ports to larger ventilation systems.

Tech Tip: Because this part is raw carbon steel, it is ready for immediate welding. We recommend a high-temperature ceramic paint or VHT coating after installation to protect the exterior from surface oxidation.