High quality forged steel con rods for all variants by K1 Technologies. H-Beam section connecting rods are forged from AISI 4340 (En24) steel. Heat treated to HRC 35-38 and then shot peened for a higher fatigue strength. Bores finished to +/- .0001" and weight to +/- 1 gram end to end. Premium bronze small ends are bushed for a fully floating pin and big ends are fitted with high quality ARP fasteners. Sold as a set of 4.