Headlock Locking Header Bolt Mr Gasket 2231G 3/8-16 x 3/4 Set of 16

Description

Product Overview

The Mr Gasket 2231G Headlock Locking Header Bolt is engineered for the demanding environment of high‑performance automotive exhaust systems. Constructed from Grade 8 steel, these bolts deliver a tensile strength of 150,000 PSI and a maximum shear strength of 86,550 PSI, ensuring they can withstand the intense pressures and temperatures generated by modern engines. Each bolt measures 3/8‑16 × 3/4 inches, a standard size that fits a wide range of exhaust headers, and the set includes sixteen pieces, providing ample spares for future repairs or upgrades.

One of the standout features of this bolt is the serrated teeth on the head, which lock directly onto the header flange. This mechanical grip creates a positive locking action that resists loosening caused by vibration, a common issue in high‑rpm applications. Complementing the serrated teeth is a proprietary thread‑lock patch that coats the threads, preventing torque loss and providing a reliable seal against exhaust gases. The combination of these two technologies ensures a secure, leak‑free connection that maintains performance over the life of the vehicle.

The bolt’s hex head design offers both strength and convenience. With a hex socket compatible with standard 13 mm (½ inch) tools, installation and removal are straightforward, reducing labor time and minimizing the risk of stripping the head. The polished exterior finish not only adds a professional appearance but also helps resist corrosion, extending the service life of the fastener even in harsh road conditions.

Each package is compact, measuring 6.1 × 4.4 × 1.9 inches and weighing just 0.7 pounds, making storage and handling easy for both professional mechanics and DIY enthusiasts. The product is backed by a warranty from Mr Gasket, reflecting confidence in its durability and performance.

Usage

These locking header bolts are ideal for a variety of automotive applications, from street‑legal performance cars to race‑ready builds. They excel in environments where exhaust heat can exceed 600 °F (315 °C), such as turbocharged or supercharged engines, where traditional bolts may soften or lose grip. The robust design also makes them suitable for off‑road vehicles that experience frequent vibration and shock.

Installation is simple: after preparing the header surface, align the bolt with the pre‑drilled holes, insert the serrated head, and torque to the manufacturer‑specified value using a standard hex socket wrench. The thread‑lock patch eliminates the need for additional locking compounds, streamlining the assembly process. Once installed, the bolts maintain a tight seal, preventing exhaust leaks that can reduce engine efficiency and increase noise.

Because the set includes sixteen bolts, it is perfect for projects that require multiple headers, such as dual‑exhaust systems or custom fabricated manifolds. The extra bolts also serve as replacements for future maintenance, ensuring that the original performance characteristics are preserved throughout the vehicle’s lifespan.

Why Choose Us

Mr Gasket is a recognized name in the automotive fastener market, known for delivering high‑quality components that meet rigorous industry standards. Each Headlock Locking Header Bolt undergoes a multi‑stage quality assurance process, including material certification, dimensional inspection, and torque testing, to guarantee consistency and reliability.

Our commitment to durability is reflected in the use of Grade 8 steel, a material grade that surpasses many OEM specifications. The bolts are heat‑treated to achieve a hardness that resists deformation under extreme temperatures, while the polished finish protects against rust and corrosion, even in coastal or winter environments.

Beyond the product itself, we provide responsive customer support and a clear warranty policy. If you encounter any issues with fit or performance, our technical team is ready to assist, ensuring that you receive the confidence and peace of mind that comes with a premium fastener solution.

Key Features

• Grade 8 steel construction delivers exceptional tensile and shear strength for demanding exhaust applications.
• Serrated teeth on the head lock directly onto the header flange, eliminating loosening from vibration.
• Integrated thread‑lock patch provides a permanent seal and prevents torque loss without additional compounds.
• Hex socket head allows quick, tool‑friendly installation with standard 13 mm (½ inch) wrenches.
• Comprehensive 16‑piece kit includes spares, and our dedicated support team ensures reliable after‑sales service.

FAQ

What size headers are compatible with the 2231G bolt?

The 2231G bolt is sized 3/8‑16 × 3/4 inches, which fits the majority of performance exhaust headers that use a 3/8‑16 thread pitch. It is commonly used on both stock and aftermarket manifolds for V‑type engines.

Do I need to apply additional thread locker when installing these bolts?

No additional thread locker is required. The bolt features a built‑in thread‑lock patch that provides a permanent, high‑strength bond, simplifying installation and ensuring consistent torque retention.

Can these bolts be used on diesel engines?

Yes. The high‑strength Grade 8 steel and corrosion‑resistant finish make the bolts suitable for diesel applications, where exhaust temperatures and vibration levels can be especially demanding.

How do I know the correct torque specification?

We recommend consulting the vehicle or header manufacturer’s service manual for the exact torque value. As a general guideline, a torque of 30–35 lb‑ft (40–48 Nm) is appropriate for most performance exhaust installations, but always verify with the specific application requirements.

What warranty does Mr Gasket offer on these bolts?

Mr Gasket provides a limited warranty covering material and workmanship defects. If a bolt fails under normal use within the warranty period, we will replace it at no cost, subject to the terms outlined in the warranty documentation.