Profab Machine makes stainless steel exhaust flanges by CNC machining for headers, turbo outlets, downpipes, and V-band joints. We make custom port shapes, bolt patterns, and plate thicknesses for non-standard and rare engines, working from your drawing or sample. Send the drawing, the sample, or the OEM or turbo part number. We will confirm the flange before quoting.
A stainless steel exhaust flange is a machined plate or ring that bolts or clamps two exhaust pipe sections together. The flange also holds the gasket or sealing face between them. The flange sits at joints such as the cylinder head to header, the turbo outlet to downpipe, and the catalytic converter to the pipe.
The port shape, bolt pattern, and thickness of a flange have to match the mating part. For that reason we machine each flange to your drawing or sample. Stainless steel also resists rust and scaling at these hot, wet joints better than mild steel does.
The mating part decides the flange, so choose the joint first, then the size and the grade. A flange with the right bolt count but the wrong port shape will not seal.
A header flange bolts the primary tubes to the cylinder head. Its port shapes, port spacing, and bolt holes must match the head. We machine the plate to your drawing or sample. The drawing also sets the plate thickness, because a thin plate can warp under weld heat.
A turbo outlet flange joins the turbine housing to the downpipe. Its bolt spacing, open or divided passage, and counterbore follow the turbo maker's drawing. We machine the flange from that drawing or from a sample, because a flange sold only as T3 or T4 may not match every turbo.
A V-band exhaust flange is turned and machined as a matched male and female pair that a stainless steel V-band clamp holds together. The flange profile has to match the clamp. We need the clamp model or a profile drawing with the pipe size.
These two-, three-, and four-bolt flanges join the downpipe, catalytic converter, flex pipe, and muffler. We machine them to the hole spacing, port shape, and gasket outline of your sample or OEM part. The replacement then bolts up and seats the same gasket.
A flange sold only as "stainless steel" may be an unknown grade. The grade, the exhaust temperature, and the salt exposure decide how long the joint lasts. For that reason, name the grade on the order.
304 is the usual grade for exhaust flanges on cars, trucks, and generators. In those uses the joint sees heat, moisture, and engine-bay wear, but not salt. 304 machines well and welds readily to 304 tube.
316L suits flanges in coastal, marine, and road-salt service, because its 2 to 3% molybdenum resists chloride pitting. However, 316L is not a higher-temperature upgrade over 304. Because of this, we review the exhaust temperature before we choose the grade.
Some turbo and race exhausts run hotter than 304 or 316L suit. Other stainless grades, such as 321, are available on request. If you give us the peak exhaust temperature and the duty cycle, we will review the grade with you.
Polishing and passivation are available on request when a flange needs a cleaner surface.
Stainless steel exhaust flanges are used at the bolted joints along an exhaust line, from the engine head to the tailpipe. Each joint needs a flange cut to its own port shape and bolt pattern. Stainless steel also keeps that flange from rusting at wet, salty joints.
Header flange plates bolt the primary tubes to the cylinder head. We machine the port shapes, bolt holes, and plate thickness to your head drawing.
Turbo outlet flanges join the turbine housing to the downpipe. We machine the bolt spacing and counterbore to the turbo maker's drawing in 304 or 316L stainless steel.
Converter flanges join the catalytic converter to the downpipe and mid pipe. We machine two-, three-, and four-bolt flanges to your sample so the gasket fits.
Muffler inlet flanges bolt the muffler to the mid pipe, a wet joint where stainless steel resists road salt and condensate. We match the hole spacing to your sample.
Tailpipe flanges join the muffler outlet to the tailpipe at the rear of the car, where stainless steel resists road salt. We machine the flange to your drawing.
Flex pipe flanges join the flexible joint to the downpipe or converter, where engine movement acts on the bolts. We machine the flange to your sample or drawing.
Work through these points before you request a quote.
| Factor | What to Confirm | Why It Matters |
|---|---|---|
| Flange family | Header, turbo, V-band, or two-, three-, or four-bolt | Each family has its own interface. |
| Mating part | Engine head, turbo model, OEM part number, clamp, or a sample | The mating part sets the port and bolt positions. |
| Port or bore | Port shape, bore, and tube outside diameter | The port must line up with the tube without a step. |
| Bolt pattern | Hole count, hole diameter, and spacing or bolt circle | A flange that nearly matches will not bolt up. |
| Thickness | Plate thickness | A thin plate can warp when it is welded. |
| Sealing face | Gasket outline, counterbore, O-ring groove, or V-band profile | The face decides how the joint seals. |
| Grade and temperature | 304, 316L, or another grade, plus the peak exhaust temperature | Temperature and salt exposure set the grade. |
| Files | DXF, DWG, STEP, IGES, PDF, or a sample | A drawing gives us the exact dimensions to cut. |
We CNC mill and turn each stainless steel exhaust flange from plate or bar. The port shape, bolt holes, and thickness follow your head, turbo, or OEM drawing.
A V-band flange pair is machined to the clamp profile you send. The male and female flanges therefore seat in the clamp.
Tell us the peak exhaust temperature and the salt exposure. We will review 304, 316L, or another grade with you before we cut the flange.
An exhaust joint also needs a clamp, hangers, and studs. These products cover them.
A V-band clamp pulls a matched pair of V-band exhaust flanges together to form the joint. Pick the clamp and the flange profile together, because they must match.
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Tube clamps hold the exhaust pipe on its hangers. That keeps the joint from carrying the weight of the pipe.
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Threaded rod cut to length makes studs for bolted flange joints.
Learn MoreNot seeing your question? Email us at [email protected] and we typically reply same day.
Send a drawing, a sample, or the OEM or turbo part number. If you have none of these, send the port or bore shape, the tube outside diameter, and the bolt count. Also send the hole size and spacing, the plate thickness, and the grade. We accept DXF, DWG, STEP, IGES, or PDF files with dimensions.
Yes, we can make the flange when you send the turbo maker's drawing, an engine head drawing, or a sample. We make each flange to the drawing or sample you send. The port and bolt pattern then match your part.
A V-band flange is the machined ring that fits or welds onto the pipe end. The clamp is the separate band that pulls two flanges together. The flange profile has to match the clamp. Please send the clamp model or a profile drawing with the pipe size.
304 suits most exhaust joints, while 316L suits coastal, marine, and road-salt exposure. However, 316L is not a higher-temperature upgrade. If you tell us the peak exhaust temperature, we will review the grade with you.
A flange can warp when a thin plate is welded to the tubes. A warped sealing face then leaks even with a new gasket. A thicker plate, a flat machined face, and a gasket that matches the face reduce that risk. However, a flange that is already cracked or badly corroded should be replaced.
Send the drawing, the sample, or the OEM or turbo part number, plus the port shape, bolt pattern, thickness, and grade.
Our engineers review your stainless steel exhaust flange request or drawing. You receive a specific quote within 24 hours.
Standard lead time for stainless steel exhaust flanges is 30 days. Custom designs are sampled before the full production run.
We ship stainless steel exhaust flanges by sea, air, or express courier. A tracking number follows once the order ships.
We support small-batch and prototype runs with no hard minimum order quantity. A first prototype run is typically around 100 pieces.
If you already have drawings, email [email protected] directly and we will quote from them.
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