2022 ARP Catalog

42 A large number of connecting rod manufacturers have chosen ARP bolts as standard equip- ment. They’re proud to advertise their products as being equipped with ARP rod bolts. And for good reason. The “weak link” in a connecting rod has always been the bolt, and racers know that nobody builds a better bolt than ARP. However, it is critically important to monitor the stretch of each bolt and replace it when it has permanently elongated by .001˝. Below you will find an extensive listing of aftermarket connecting rods and replacement bolt specifi- cations. You should also know that ARP rod bolts are superior to those from other manufacturers – especially in the area of fatigue strength. Testing has shown ARP rod bolts to have twenty times the fatigue strength of other bolts. As such, it makes good sense to rely on ARP for optimum connecting rod service and reliability. Make the most of your racing budget and rely on ARP rod bolts. You’ll find the ARP name proudly stamped on each bolt as your assurance of quality. Aftermarket Connecting Rod Bolts ARP Connecting Rod Bolt Material Overview 8740 CHROME MOLY: 8740 chrome moly is seen as a good tough steel, with adequate fatigue proper- ties for most racing applications, only if the threads are rolled after heat-treatment, as is ARP’s standard pro- cedure. Chrome moly can be heat-treated to deliver tensile strengths between 180,000 and 200,000 psi. ARP2000®: ARP2000 is an steel alloy that can be safely heat treated to a higher level than 8740. While 8740 and ARP2000 share similar characteristics – ARP2000 is capable of achieving a tensile strength of 220,000 psi. Stress corrosion and hydrogen embrittle- ment are typically not a problem. L19®: L19 is a very high strength material capable of delivering a tensile strength at 260,000 psi. L19 re- quires special care to avoid hydrogen embrittlement. This material is easily contaminated and subject to stress corrosion. It must be kept well-oiled and not exposed to moisture. ARP3.5® (AMS5844): The high cobalt content of this alloy, while expensive, delivers a material with superior fatigue characteristics and typical tensile strength in the 260,000-280,000 psi range. The immunity to hydrogen embrittlement and corrosion is a significant design con- sideration. This material is primarily used in connecting rods where extremely high loads, high RPM and endur- ance are important factors. CUSTOM AGE 625 PLUS®: This super-alloy demon- strates superior fatigue life, tensile strength and toughness – with complete resistance to atmospheric corrosion and oxidation. ARP is the first to develop manufacturing and testing processes for fasteners with Custom Age 625+. Typical tensile strength is 260,000- 280,000 psi. ROD BOLTS