ARP Engine Connecting Rod

ARP Connecting Rod Bolts: The Fastener Behind Every Reliable Build

When engine builders and racers talk about the "weak link" in a connecting rod assembly, the conversation always circles back to the bolt. ARP (Automotive Racing Products) has spent decades making sure that weak link becomes the strongest one. Their engine connecting rod bolt lineup is one of the most respected in motorsports, trusted by professional engine builders and weekend racers alike across virtually every engine platform imaginable.

A Tiered Material System Built for Every Power Level

What separates ARP from generic fastener suppliers is a rigorously engineered, tiered material hierarchy that matches bolt alloy to application demands:

• 8740 Chromoly Steel – ARP's entry-level performance option is anything but basic. These bolts are made of premium grade 8740 chromoly steel and heat treated to a nominal tensile strength of 200,000 psi. Critically, ARP uses only SDF (seamless and defect-free) and CHQ (cold head quality) grades, even though they cost more than double "Aircraft" quality.
• ARP2000 Alloy – The most popular upgrade for forced-induction and high-revving builds. ARP2000 is capable of achieving a clamp load at 220,000 psi and is used widely in short track and drag racing as an upgrade from 8740 chrome moly in both steel and aluminum rods.
• L19 Alloy – L19 is capable of delivering a clamp load at 260,000 psi and is primarily used in short track and drag racing applications where inertia loads exceed the clamping capability of ARP2000.
• Custom Age 625 Plus – ARP's top-tier exotic alloy. The high cobalt content of this alloy delivers a material with superior fatigue characteristics and typically tensile strength in the 260,000–280,000 psi range, with immunity to hydrogen embrittlement and corrosion.

Patented Wave-Loc Technology and Pro Series Precision

Across the product lineup, ARP incorporates proprietary engineering features that go well beyond raw material strength. The patented Wave-Loc surface design provides superior material grain flow compared to knurled bolts, which have sharp edges and built-in stress risers — virtually eliminating galling and scoring of the rod.

ARP Pro Series connecting rod bolts are precision CNC-machined to exacting specifications and designed for optimum reliability. They are heat-treated and threads are rolled to provide up to ten times more fatigue strength. The large underhead radius enhances clamping strength, while ARP's patented Wave-Loc surface design optimizes material grain flow, reducing the risk of galling or rod scoring.

Broad Application Coverage

ARP's connecting rod bolt catalog spans an enormous range of domestic and import platforms. From classic small-block Chevy and Ford applications to modern GM LS engines, Mopar Hemi Gen III, and a wide array of import Sport Compact engines, ARP engineers application-specific kits rather than one-size-fits-all solutions. A large number of connecting rod manufacturers have chosen ARP bolts as standard equipment and are proud to advertise their products as being equipped with ARP rod bolts.

All ARP fasteners are proudly made in the USA to the industry's highest standards. Whether you're building a street cruiser, a nitrous-fed bracket car, or a full-race powerplant, ARP's connecting rod bolt lineup offers a proven, application-specific solution backed by decades of motorsports engineering. Browse the full selection of engine connecting rod bolts or explore the complete ARP fastener catalog to find the right hardware for your build.