Set of 6 - 2.5" Inch Mandrel Bend Exhaust Pipe 409 Stainless Steel 3x 45 & 3x 90 Deg

Set of 6 pieces of 2.5" Inch Exhaust Pipe 409SS Mandrel Bends

3pcs of 45 Degree & 3pcs of 90 Degree

Specifications:

Outer Diameter 2.5" Inch, 2-1/2" (63.5mm)

Wall Thickness: 1.6mm

409 Stainless Steel (Unpolished)

Leg Lengths:

45° Leg Length - 120mm

90° Leg Length - 110mm

409 stainless steel is superior to mild steel for exhaust piping due to its higher chromium content, which provides excellent resistance to oxidation and corrosion at elevated temperatures. Unlike mild steel, which quickly deteriorates from heat cycling and exposure to moisture, 409 stainless maintains structural stability, resists scaling up to extreme temps of 675°C, and offers much longer service life. This balance of strength, heat resistance, and corrosion protection makes it the industry standard for OEM and aftermarket exhaust systems.

These 409 stainless steel mandrel bends by GASO provide superior thermal reflectivity and corrosion resistance compared to untreated mild steel. The tube features a 2.5" outside diameter in 409 stainless steel (unpolished), enhancing oxidation resistance at elevated temperatures.  409 SS is also weldable using both MIG and TIG processes, though post-weld cleaning is recommended to minimise surface oxidation. Can be used with clamps also.

Stainless Steel & Magnetism (Important - Please Read)

409 stainless steel is magnetic. This is normal and does NOT mean it is mild steel.

There is a common myth that stainless steel should never attract a magnet. This is incorrect. Magnetism and corrosion resistance are not connected.

Corrosion resistance depends on chromium (and sometimes molybdenum) content - not magnetism.

There are different families of stainless steel:

• 304 & 316 (austenitic) - usually non-magnetic, higher chromium content, higher corrosion resistance

• 409 & 430 (ferritic) - magnetic by nature, designed for automotive and exhaust use

Our mandrel bends are Grade 409 stainless steel, which contains approximately 11% chromium. This is specifically engineered for exhaust systems and is widely used by OEM manufacturers for mufflers and piping due to its:

• Heat resistance

• Strength

• Cost efficiency

• Suitable corrosion resistance for automotive environments

For comparison:

• 409 stainless - ~11% chromium (automotive exhaust systems)

• 430 stainless - ~16% chromium (mostly indoor applications)

• 304 stainless - ~18% chromium (general outdoor use)

• 316 stainless - includes molybdenum (marine environments)

Even “non-magnetic” grades like 304 can become magnetic after bending or forming - try a magnet on your kitchen sink.

Summary

If your magnet sticks - that is expected for 409 stainless.
It does not mean mild steel.
It does not mean incorrect material was supplied.

Grade 409 is an industry-standard exhaust stainless chosen for durability under heat cycling and real-world driving conditions.