Universal Exhausts

Exhaust flange – an essential component of a car’s silencer

For a silencer to effectively absorb the noise emitted by a car’s engine, it must be fitted with a suitable flange. The exhaust flange enables the individual parts of the exhaust system to be connected. We offer a wide range of universal-fit products that are suitable for use in vehicles of various makes. On our website, you’ll find high-quality exhaust flanges. Once securely welded to other components of the exhaust system, they will form a single unit with it and operate reliably for a long time.

Repair your exhaust system using an exhaust flange

We stock INOX stainless steel flanges made from acid-resistant steel grades AISI 304, 1.4301 and 0H18N9, with various technical specifications. Thanks to this material, we can be confident that the exhaust flange we offer will serve you well for many years to come. We offer not only 3-bolt flanges with a thickness of 8 mm and a central bore diameter of 60 mm or 76 mm. Our range also includes 2-bolt exhaust flanges for connecting pipes with diameters of 88/90 mm or 63/5 mm. Stainless steel flanges allow you to fix faults in your car’s exhaust system yourself, without having to dismantle the entire system. If you want your car’s exhaust to run more quietly and efficiently, try an exhaust flange from our range. It is a tried-and-tested solution for restoring the exhaust system’s seal.

When the exhaust system starts to leak exhaust fumes at a joint or requires modification without replacing the entire section, well-chosen pipe flanges allow you to resolve the issue quickly without having to fit random components. This category includes universal exhaust flanges for connecting pipes with diameters ranging from 38 to 90 mm, made from acid-resistant INOX stainless steel.

The differences between models are not limited to diameter alone. The fit is determined by the diameter of the pipe bore, the bolt pattern, the material thickness and the operating conditions of the entire joint, particularly when the exhaust pipe flange is used with pipe fittings, exhaust hoses or an older section of the exhaust system.

How do you select pipe flanges to suit the diameter and type of connection?

Pipe flanges connect sections of the exhaust system and are selected first according to the actual external diameter of the pipe, and only then according to the method of fastening. Even a single millimetre’s difference matters, as a connection that is too loose makes welding or alignment difficult, whilst one that is too tight requires machining, which weakens the edge. In practice, it is best to measure the pipe with a calliper at the cut end, rather than in an area distorted by corrosion or a previous weld.

The pipe diameter takes precedence over the variant name

In this category, flanges are available for pipes with diameters of 38, 45, 50.8 or 51, 54, 57, 60 or 60.3, 63.5, 64, 70, 71, 76 and 88/90 mm. It is also worth checking for deviations following previous repairs, as an old pipe may deviate from its nominal dimension. Exhaust flanges are selected to match the cross-section of the joint, not the make of the car.

When taking measurements, it is best to check three points:

• the pipe diameter on the installation side,
• the spacing and number of bolt holes,
• space for flange gaskets or a weld.

Standard or 3-bolt version?

The standard version is suitable where the joint has a simple layout and is easily accessible to tools. 3-bolt versions provide more even clamping pressure around the circumference and are often more suitable for sections exposed to vibration. The clamping arrangement must be adapted to the other part of the joint, as diameter compatibility alone does not guarantee a leak-tight seal.

Why do stainless steel flanges last longer in the exhaust system?

Stainless steel flanges prove their worth where ordinary steel flanges rust quickly and lose their flatness. AISI 304 INOX acid-resistant steel withstands moisture, salt and heating cycles better, whilst the 8 mm thickness reduces the risk of warping during welding and when operating under thermal stress.

This is a practical benefit. A stiffer flange stabilises the joint, maintains the clamping force and helps to preserve the full cross-sectional area for exhaust gas flow, which aids noise reduction and prevents the formation of an unnecessary step at the joint.

How can you tell if an exhaust pipe flange is leaking?

A leaky exhaust pipe flange usually produces audible symptoms sooner than visual signs appear. A worn or poorly tightened joint causes a metallic hissing sound after starting the engine, soot marks around the joint and more pronounced vibrations when the load changes. During prolonged driving, the leak may cause the bolts to loosen or burn the contact surface.

The most common symptoms include:

• a dark deposit at the edge of the connection,
• louder system noise when cold,
• the smell of exhaust fumes under the car or near the centre console,
• uneven clamping pressure after unscrewing the joint.

Fitting and sealing the joint without common mistakes

Fitting the flange begins by cleaning the pipe edges and checking that both surfaces are coaxial. Simply tightening the bolts will not seal misaligned pipe connections. If the connection requires flange gaskets, these must be selected to match the diameter and bolt hole spacing; if welding is required, it is advisable to carry out spot welding whilst checking the alignment before completing the full circumference.

The most common installation errors include:

• tightening bolts without first ensuring coaxiality,
• joining components of similar but not identical diameters,
• welding on a dirty or corroded edge,
• failing to carry out a check after the first heating cycle.

A well-chosen exhaust flange allows a section of the system to be repaired or rebuilt without replacing the entire assembly. When selecting one, simply compare the pipe dimensions, the mounting type and the operating conditions of the joint.

FAQ

How do you measure a pipe accurately before buying a flange?

Measure the external diameter with a calliper at the cut end, not on a corroded section. Also check the spacing and number of holes, as well as the space for a gasket or weld, to ensure the flange fits without further machining.

When is it worth choosing an 8 mm thick AISI 304 flange?

When the system operates in damp or salty conditions, or undergoes frequent heating cycles — AISI 304 stainless steel and an 8 mm thickness better withstand corrosion and warping, whilst maintaining seal pressure and flue gas flow.

How do you match the flange bolt pattern to an existing connection?

Compare the spacing and number of holes with the other part of the joint; 3-bolt versions provide even clamping force, but check for concentricity before tightening, as the diameter alone is not sufficient.