API International is your premier partner in supplying industrial fittings for the Exhaust industry. With a commitment to excellence and a wide array of high-quality product offerings, we cater to the unique needs of the Exhaust Industry. Our extensive inventory includes steel flanges, expansion joints, grooved fittings, custom-machined components, and OEM products, all designed to meet the industry's stringent requirements.
We understand the vital role of reliable fittings in ensuring optimal exhaust system performance, longevity, and safety. Our expert team combines years of experience with cutting-edge technology to deliver solutions that exceed expectations. Whether you're looking for precision-engineered parts or specialized components, our comprehensive range and dedication to customer satisfaction make us a leading supplier. Join countless satisfied customers who trust API International for their exhaust fitting needs.
We begin by understanding your goals, whether it's reducing cost, improving quality, or launching a new product. Together, we define technical and commercial requirements to ensure full alignment from the start.
With worldwide manufacturing resources, API International provides both standard and custom flange solutions. Our network of facilities and in-house expertise allow us to deliver the right fit for your needs, whether it’s off-the-shelf or built to specification.
Our engineers work closely with customers to refine designs, reduce costs, and ensure manufacturability. We stay connected with your team throughout to keep progress clear and efficient.
After final review of samples, production begins. Our team oversees quality and delivery coordination to ensure smooth execution and traceability from start to finish.
Exhaust flanges are specified by the bolt pattern and dimensional standard required to match the engine, manifold, or equipment connection, e.g., Caterpillar, Cummins, Detroit, Mitsubishi, etc. Square and round flanges are commonly used in industrial exhaust applications. Flanges built to ANSI/ASME drilled patterns (often referenced by pressure class such as Class 150/300). The material used for these exhaust flanges meet AWWA C207 specifications and are suitable for high temperature applications. This AWWA standard covers steel plate flanges, which are commonly used in custom or standard exhaust fabrication. 1/2″ and 5/8″-thick flanges are also common as well.
Common exhaust flange materials include carbon steel, such as ASTM A36 or ASTM A105. They are often used when cost is a priority, and the risk of corrosion is managed. Stainless steel, such as ASTM grades 304L or 316L, is often selected for better corrosion resistance and longer service life.
It depends on many factors, and risk should be determined in accordance with the project’s specifications. In most exhaust environments, carbon steel (ASTM A36 or ASTM A105) is the standard choice because it offers a strong balance of corrosion resistance, heat performance, and cost. 304L/316L stainless is typically selected when corrosion exposure is more severe, such as salt-heavy environments, coastal/marine exposure, or chemical contact, because it offers improved resistance in harsher conditions.
Yes, gaskets are usually recommended between exhaust flanges to make a tight, leak-free seal. They help compensate for surface imperfections and prevent exhaust gas leaks, which can impact system performance and safety. But you should always refer to your project requirements for exact usage.
You can purchase high-quality exhaust flanges directly from API International. We manufacture and distribute a wide variety of steel and stainless steel plate flanges, including AWWA C207 compliant parts for exhaust applications.
API International is known for:
Fast nationwide shipping from multiple U.S. warehouses
High stock levels of both AIS and imported products
Expert customer service and technical support
Reliable solutions for exhaust, water works, HVAC, and more
Visit our website or contact our team to get the flanges you need.
At API International, our custom manufacturing capabilities set us apart. With an in-house machine shop, we transform your designs into precision parts quickly. From single prototypes to full production runs, we deliver cost‑effective pricing, dependable performance, and rapid turnaround. Flexible material options and rigorous quality checks ensure consistency from part to part.
99.5% order accuracy rate
Our boots-on-the-ground approach ensures close collaboration with our suppliers. Every flange, valve, and fitting undergoes rigorous inspection and thorough documentation, ensuring consistent performance and reduced field issues.
Active customers in all 50 states + Canada and Mexico
When your schedule is on the line, knowing our U.S. warehouses are stocked and orders ship same-day gives you peace of mind, so you can focus on the task at hand, not the clock.
700+ machined-to-spec parts created each year
Collaborate directly with our engineers to bring your unique specifications to life, ensuring every component performs as if it were built with your project in mind.
1,500+ unique customers served over 45+ years
Our dedicated account team partners with you from quote to delivery, answering questions and offering expert advice so you can make confident decisions and avoid costly delays.
