Turbo Accessories
T4/T6 COMBO 316 STAINLESS STEEL TURBO INLET FLANGE 3/8″ STANDARD
KEY FACT
The T4/T6 Combo Turbo Inlet Flange is a 3/8″ (9.5 mm) 316 Stainless Steel precision-machined component designed for both T4 and T6 footprint turbos using a single dual-pattern flange. CNC laser-cut to ±0.003-inch flatness, ASTM A240 316 certified, and priced at $68.00 — in stock with same-day dispatch.
SKU: TIFT4T6316STAINLESSSTANDARD
It accepts both T4 and T6 bolt patterns in a single piece (8 × M10/M12), eliminating the need to source two separate flanges across a mixed-platform build. Manufactured from ASTM A240 316 stainless steel with added molybdenum, it handles 925°C (1700°F) continuous and outperforms 304 in chloride-rich and methanol environments. The 3/8-inch standard thickness suits the vast majority of passenger car and light truck builds. Every flange is CNC laser-cut and surface-ground to ±0.003-inch flatness with bolt holes reamed to H7 tolerance, providing a gas-tight metal-to-metal seal without a gasket on properly prepared turbos.
✓ Free shipping on orders over $150
✓ Same-day dispatch on orders before 2 PM EST
✓ 30-day returns for unused items
✓ Pickup available in Miami, FL 33172 — by appointment
Technical Specifications
| Inlet Port Size | 3.32–4.09 in |
|---|---|
| Flange O.D. | 5.45 × 4.55 in |
| Bolt Pattern | 8 × M10/M12 |
| Thickness | 3/8″ (9.5 mm) |
| Max Temperature | 982°C / 1800°F |
| Material | 316 Stainless Steel |
| Standard | ASTM A240 316 |
| Surface Finish | Ra 1.6 μm brushed |
| Flatness | ±0.003 in |
| Bore Tolerance | H7 reamed |
Material Comparison Guide
304 Stainless vs 316 Stainless vs Carbon Steel vs Inconel 625 — your selection is highlighted
| Specification | 304 Stainless | 316 Stainless YOUR SELECTION | Carbon Steel | Inconel 625 |
|---|---|---|---|---|
| Max Continuous Temp | 871°C (1600°F) | 925°C (1700°F) | 425°C (800°F) | 1093°C (2000°F) |
| Corrosion Resistance | Good | Excellent | Poor (needs coating) | Excellent |
| Weldability | Excellent | Excellent | Excellent | Good |
| Cost (relative) | $$ | $$$ | $ | $$$$ |
| Best For | Street / track | Marine / E85 / diesel | Budget builds / coated manifolds | Extreme boost / compound turbos |
| Standard | ASTM A240 304 | ASTM A240 316 | ASTM A36 | AMS 5666 |
| Recommended Gasket | Optional | Optional | Recommended | Optional |
Frequently Asked Questions
About the T4/T6 Combo 316 Stainless Steel Turbo Inlet Flange 3/8″ Standard
Does this flange fit my turbo?
Yes — the T4/T6 combo flange supports both T4-footprint (Garrett T04E, Precision 6262) and T6-footprint (Precision 88mm+, BW S475) turbos using its dual bolt pattern. It is not compatible with T3 or V-Band turbos.
Why should I choose 316 Stainless Steel for a turbo inlet flange?
316 stainless adds molybdenum, which dramatically improves resistance to chloride corrosion and raises the service temperature ceiling versus 304. It is the correct choice for marine environments, diesel builds, and any car running E85 or water-methanol injection.
Should I choose the 3/8-inch or 1/2-inch thickness?
For most builds, the 3/8-inch (9.5 mm) standard thickness is sufficient. Choose the 1/2-inch heavy-duty option only if you have a diesel engine, a large-displacement V8 with a rigid downpipe, or a setup that places significant cantilever stress on the flange joint.
How do I install the T4/T6 Combo turbo inlet flange?
Clean the turbo inlet face and remove all old gasket material. Align the flange with the 8 bolt holes and thread the M10/M12 bolts in finger-tight. Torque in a cross pattern to spec (M8: 18–25 Nm · M10: 30–40 Nm · M12: 50–65 Nm). A 1/16-inch Cometic MLS gasket is recommended on builds over 25 PSI.
Does this flange need a gasket?
A gasket is not strictly required — the face is ground to Ra 1.6 μm, which creates a metal-to-metal seal on most turbos. However, a 1/16-inch multi-layer steel (MLS) gasket is recommended for builds over 25 PSI boost or on turbos with minor surface irregularities.
What is the price of the T4/T6 Combo 316 Stainless Steel Turbo Inlet Flange 3/8″ Standard?
The T4/T6 Combo 316 Stainless Steel Turbo Inlet Flange 3/8″ Standard is $68.00 per piece with free shipping on orders over $150. It is in stock and ships same day when ordered before 2 PM EST.