Stainless Steel Exhausts Bradford: Pro Flo’s Custom Build Process

People often ask us what separates a custom-fabricated stainless exhaust from a standard replacement part. The honest answer is: everything from the material quality and the weld integrity to the precise fit and the attention paid to your specific vehicle. At Pro Flo on Canal Road, Bradford, we’ve been building stainless exhaust systems since 2004, completing well over 1,000 custom builds in that time. This article takes you through what actually happens when you bring your vehicle to us.

Step 1: Assessment and Measurement

Every build starts on the ramp. We put your vehicle up and examine the existing exhaust system in detail — what’s there, what condition it’s in, and what we need to work around or replace. We check the fitment points, hanger positions, clearances to bodywork, heat shields, and the condition of any sections that are being retained.

Measurement is critical. Unlike an off-the-shelf part that is stamped to a standard template, our builds are measured directly from your vehicle. We note the exact routing the pipe needs to follow, the clearances available, and any particular challenges — a lowered ride height, aftermarket components in the way, bodywork modifications that have changed the standard exit position. This stage is where experience really counts. After 20+ years and hundreds of different vehicles, we know the common issues and the best approaches to resolve them.

Step 2: Material Selection — T304 Grade Stainless

We use T304 grade stainless steel for all custom builds as standard. This is the correct choice for exhaust work — not a marketing claim. T304 is an austenitic stainless steel with 18–20% chromium and 8–10% nickel, giving it genuine corrosion resistance through a self-repairing oxide layer rather than a coating that can fail.

We stock pipe in a range of diameters and wall thicknesses to suit different applications. A performance build on a 2.0-litre turbo uses different bore dimensions than a standard replacement on a 1.2-litre naturally aspirated engine — and we specify accordingly to optimise flow for each specific vehicle.

Step 3: Pipe Bending and Shaping

Stainless steel requires mandrel bending — a technique that supports the pipe internally during the bend to prevent the wall collapsing or kinking. This produces a smooth, consistent bore through the bend rather than the restriction that results from crimped or kinked pipework. Our pipe bending equipment handles this correctly, producing clean, consistent curves that follow the vehicle’s routing requirements without compromising flow.

Where bends are tight or the geometry is complex, we may use pre-formed bend sections and join them precisely to achieve the correct angle. This is normal practice in quality exhaust fabrication and, when done correctly, produces a result indistinguishable from a single-piece bend.

Step 4: TIG Welding

This is arguably the most important step, and it’s where quality fabrication is really distinguished from budget work. TIG (Tungsten Inert Gas) welding produces stronger, cleaner welds than MIG on stainless steel. The process uses a non-consumable tungsten electrode, a separate filler rod, and an argon shielding gas to produce a precise, fully penetrating weld with minimal spatter and excellent appearance.

Our welders are experienced in stainless exhaust fabrication. A good TIG weld on an exhaust joint is structurally stronger than the pipe itself, will not corrode at the join, and seals completely against exhaust gas leakage. Poor welding — weak penetration, porous welds, or excessive heat input that damages the surrounding material — is the primary cause of premature failure on fabricated exhaust systems. We take this stage seriously.

Step 5: Fitting, Sealing, and Mounting

Once the system is fabricated, we fit it to the vehicle and check it at every mounting point. Correct hanging is as important as the fabrication itself — an exhaust that is poorly supported will transmit vibration, move against other components, and eventually fracture at stress points. We use quality rubber hangers, correctly positioned to allow the system to expand thermally without stress.

Flange connections and join points are sealed with high-temperature exhaust paste where appropriate, and joints are torqued correctly. We also check all heat shields are correctly positioned and secured.

Step 6: Sound Test and Final Inspection

Before handing your vehicle back, we run the engine and listen carefully. We check for any leaks (audible as a ticking or blowing), any rattles against bodywork or other components, and the overall sound character. For customers who specified a particular sound target, this is the point where we confirm the result matches expectations.

Same-day fitting is available in most cases — for straightforward builds on common vehicles, it’s normal to arrive in the morning and collect in the afternoon. For more complex custom builds, we may ask you to leave the vehicle with us. We’ll always give you a realistic time estimate before work starts.

If you’re in Bradford or West Yorkshire and want a stainless exhaust built properly, come and see us at 365 Canal Road. We’re open Monday to Saturday, 9am to 6pm.