iE HoldStrong Head Studs For B9 Audi S4/S5/SQ5 3.0T / RS5 2.9T

KEEP IT TOGETHER
Meet your ultimate defense against head lift. iE HoldStrong Head Studs are engineered and manufactured for structural integrity to go toe-to-toe with the demands of high-output engines. They’re made to keep your engine together and sealed tight using a rolled-thread process, chromium-based H11 tool steel and aircraft grade J-threads for maximum strength.

CHROMIUM H11 TOOL-STEEL
It’s not rocket science, but it’s close. Our chromium-based H11 tool steel alloy is known for its use in aerospace industry applications like helicopter blades and landing gear. H11 is widely used for its crack-resistant properties to prevent thermal fatigue or thermal shock. This alloy’s low-carbon content gives it strength with minimal distortion when tooling. If it’s good enough to land a plane, it’s the right choice for your high-performance engine.

Unlike stock stretch bolts, HoldStrong head studs do not stretch to torque and are reusable.

IT'S ALL IN THE THREADS
iE head studs are manufactured using a rolled method in a pure oil solution. The alloy material is shaped rather than removed (cut) which creates a compressive force that strengthens the thread and eliminates imperfections that could cause stress cracks. Rolled threads are built for strength and extreme fatigue resistance.

1- Precise surface finish
Roll forming the threads in a contained die produces an incredibly smooth thread surface that greatly reduces the chances of stress cracks.

2- Compressed material
Instead of removing material, the alloy is compressed to form the threads which greatly increases strength and fatigue resistance. To maintain the structural integrity of the material during this process, heat caused by friction is reduced using a cooling oil.

3- Accurate thread profile
The precise thread forming also produces a very consistent thread profile and dimensional accuracy, which delivers greater thread engagement and improves the overall performance of the fastener.

TRADITIONAL CUT THREADS

1- Surface imperfections
The thread surface of a machined (cut) fastener is at risk to surface chatter and burrs. These small imperfections can cause stress concentrations and thread failure.

2- Removed material
Forming the threads by cutting material away removes and weakens the alloy. Less material means lower strength and fatigue resistance.

3- Unstable thread profile
While faster and cheaper to produce, cut threads can not maintain a truly consistent thread profile, making them less than ideal for critical clamping loads required for performance builds.

NOT ALL THREADS ARE EQUAL
The sharp edges and corners of standard cut thread can cause stress points that lead to bolt failure. To prevent this, iE head studs have been engineered with J-threads. This higher quality thread profile has a curved minor-diameter structure to reduce stress points and prevent breakage from vibration. J-threads also provide a more accurate sizing for an exact dimensional fit.

WHAT IS HEAD LIFT?
The Audi B9 3.0T EA839 engine is an absolute powerhouse capable of over 739 HP and 710ft-lbs with simple hybrid turbo bolt-on upgrades. These massive gains also result in higher cylinder pressures that put a lot of stress on the factory head bolts. When the factory bolts hit their limit, they stretch and cause head lift. This breaks the cylinder head gasket seal which results in compression loss, oil/coolant contamination, loss of power, and in extreme conditions; catastrophic engine failure.

LEADING FEATURES

• Turn it up -Engineered to meet the demands of high-power engines
• 211 ksi yield strength -Never worry about head lift again
• Ultimate strength -Chromium-based H11 tool steel alloy
• Aerospace-style J threads -Minimizes stress points
• Rolled threads in pure oil solution -Precision thread profile