Honda B18C H-Beam connecting rod Eagle

All Eagle H-beam rods are forged from certified 4340 chromoly steel. While a lot of companies make rods from this material, if you pay close attention, you will notice not all 4340 is the same. For instance, to be classified as "4340 steel" certain alloying elements must be present in certain percentages. AISI/SAE specifications call for 1.65% to 2.00% nickel content. While this seems like a small difference, understand that this is almost an 18% variation. 4340 steel with 1.65% nickel will act a little differently than 4340 steel with 2.00% nickel content. This is just one of many alloying elements involved in creating 4340 steel. Through extensive material testing, Eagle works closely with the foundry we use to achieve a much tighter tolerance of all alloying elements to our specific requirements. Along with this, the heat treatment and tempering process used is vital to producing a stong steel. While exactly what we do is a closely guarded secret, all of this attention to detail results in a stronger and much more consistent material. Our "4340" steel routinely tests 10-15% stronger than "typical" SAE/AISI spec 4340 steel.Another important design feature is all Eagle H-beam rods are manufactured from a 2 piece forging. This is significant because it enhances the strength of the rod cap by orienting the "grain" of the metal with the direction of stress. The stress exerted on the cap is perpendicular to the stress on the beam