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400 Series Stainless Tube


439 Stainless Steel Tube

439 Stainless Headers

439 stainless steel tube is a ferritic stainless steel that outperforms Type 409 and Type 436 in both oxidation resistance and corrosion resistance. Special attention to chemical composition combined with special processing give 409 stainless steel tube optimum formability that is reproducible, coil after coil, and heat after heat. This provides special advantages when producing difficult-to-form exhaust systems components. Oxidation and corrosion resistance that is superior to Type 409 makes 439 stainless steel tube attractive for numerous automotive exhaust applications.

Typical uses include tubular manifolds and other exhaust system components where temperatures may exceed the oxidation limit of Type 409 and Type 436, or where wet corrosion resistance, particularly to chlorides, is needed.

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Why Choose Middletown Tube?

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More Than Steel

More than steel makes a Middletown tube. Our tubes exceed ATSM and industry standards by as much as 200%. Through destructive testing, we try each tube for weaknesses and strengths. Our XIRIS post-weld inspection uses laser-camera triangulation to measure weld geometry and contour irregularities.

It’s more than steel that makes a tube less likely to fail, split or break. A tube that follows lean manufacturing techniques and reaches a level of implausible lightweighting, allowing you to save resources and create better products. People with over 20+ years of experience make a Middletown tube, keep our 27 mills running to the tune of a 4-week turnaround and on-time delivery.

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Our Steel

Not just any steel becomes a Middletown steel tube. To find the most consistent and reliable steel, we trialed steel from mills both domestic and international. Time and again, AK Steel met our exact standards. Coil to coil, AK Steel adheres to the strictest chemistry and thickness control.

It’s pure American steel, the highest-rated; which is why 85% of our steel is AK Steel. To provide you superior service, we’ve located our mill next door to AK Steel.

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Onsite Metallurgical Lab

Heat and pressure may form Middletown Tube, but it’s research and innovation that mature it. Our onsite metallurgical lab tirelessly works towards higher standards of craft and precision with special attention to your specific requirements.

Our lab also troubleshoots customer and competitor tubing. To determine failure causes, we run an array of tests: Coating, metal composition, chemistries, hardness, gauge and more. With diagnosis in hand, we then provide the right tubing solution.

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Lock Down Steel Pricing

A steel coil warehouse is a rare, money-saving asset for customers. To help insulate you from fluctuations in steel prices, Middletown Tube offers the option of price lock. A large volume purchaser, Middletown Tube fills our dedicated warehouse with coils for contract customers.

Customers may lock in their steel rate for an entire year without worry of an increase in price. Middletown Tube carries the cost and stores the steel.

No Tube Should Be One-Size-Fits-All


Whatever the specification, Middletown Tube can match your exact need.

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