SpeedFactory Titanium Manifold Stud M8x1.25x55mm (Single)

Bolted a Skunk2 intake manifold or a thermal gasket onto your B18 and found the stock studs barely catch three threads? That's the job this stud exists for. This is a single SpeedFactory titanium manifold stud in M8x1.25x55mm, with a titanium 12-point nut and washer, sold one at a time. The extra 10mm over the standard 45mm stud is there to make up for thicker aftermarket flanges and gasket stacks.

What It Is and Why It Works

SpeedFactory machines these from Ti 6Al-4V, the same Grade 5 titanium used in aerospace hardware. It's stronger than factory steel and it won't rust, which is why the original studs on a 25-year-old Honda snap the moment you put a wrench on them. A 3mm hex key tip is machined into the end of the stud, so it threads into the head with an Allen key instead of the double-nut trick. The complete assembly weighs about 13 g, per manufacturer.

The M8x1.25 thread pitch matches the intake and exhaust manifold studs on Honda and Acura B series (B16, B18, B20), D15 and D16, F20B, the S2000's F20C and F22C, and the Prelude's H22 and H23. It also fits the intake side of a K series head. K series exhaust manifolds use M10x1.25, so this won't work there.

Length is the whole buying decision on these. The 45mm stud handles stock manifolds and standard headers. This 55mm version is for aftermarket intake manifolds, thermal or phenolic gaskets, and stacked spacer setups where the combined flange and gasket thickness eats up thread engagement. If your stack is thicker still, SpeedFactory makes a 65mm single too. Measure your flange plus gasket before ordering and you'll only do this job once.

Specs

Available Options

Fitment

Thread pitch decides fitment on hardware like this, not the chassis. Any Honda or Acura manifold location running an M8x1.25 stud takes this part, including B16 Civics, B18A and B18B Integras, and swapped EG, EK, and DC2 builds on B, D, F, or H series power. Confirm your original hardware is M8x1.25 and measure your flange stack before ordering.

What to Know Before You Buy

Don't default to the longer stud thinking more is better. On a stock manifold or a thin header flange, the extra 10mm of exposed stud can interfere with tight runner bends and makes 12-point nut access worse, and it looks unfinished. Pick 55mm because your stack actually needs it, usually an aftermarket intake manifold or a thermal gasket, otherwise the 45mm is the right part.

Install is the same drill as the rest of the family. Hand-thread the stud into a clean bore, snug it with the 3mm Allen key, and don't lean on the hex tip, it's an install feature, not a torque point. Clamp load comes from the nut, torqued to your factory manifold spec. Titanium in an aluminum head can gall, so use a nickel-based anti-seize on the threads and plan a retorque after a few heat cycles, especially on exhaust or turbo manifold duty. If you're refreshing the whole manifold rather than replacing one bad stud, the SpeedFactory 10-piece titanium stud kit we carry covers a full B, D, F, or H series manifold in one shot.