Edelbrock one-piece hardened steel pushrods are manufactured from high quality 4130 Chromoly steel tubing that has been surface hardened for maximum durability. They have precise formed swedged ends for a high quality fit with the cup seats. A black oxide finish is added for corrosion resistance. All Edelbrock pushrods are 5/16 in diameter, except for #9605, #9618, #9635, #9647 and #9648 which are 3/8 O. D. Sold in sets of 16.