Chromoly Vs Mild Steel

In this short video tim mcamis explains some of the differences between 4130 chromoly and mild steel tubing for use in drag race chassis construction.

Chromoly vs mild steel.

Chromoloy tubing is made from a family of low alloy steels that contain chromium and molybdenum sae 4130 or 4140 along with the iron carbon and other elements. The dragsters usually have to be backhalved after so many laps. This increased strength to weight ratio in chromoly allows for the use of thinner walled tubing to obtain the same structural support. It was designed for and is used extensively in the aircraft industry due to it s high tensile.

Given the same o d. It is a steel that is stronger than carbon steel more commonly used in bike manufacturing so we can use thin wall tubing giving you a lightweight frame that will last through years of riding. Chromoly is a chrome alloy steel with a medium carbon content and 8 1 1 molybdenum for strength. One of the never ending topics of conversation is the use of 4130 steel over mild steel in professional drag racing builds.

The most common source of argument surrounding the construction of a chromoly frame is the welding process. Chromoly steel is often used when more strength is required than that of mild carbon steel though it often comes at an increase in cost. Crome molly i have mild steel in my own car and all the dragsters are 4130 molly. While you probably won t stress them out like we do i have seen them break while riding in the trailer.

Cage mild steel vs. A common misconception is that chrome moly is lighter than mild steel. Chromoly falls under the the aisi 41xx designations and it is important to be aware of the different properties and applications of chromoly steel when deciding which material you need. And wall thickness a chrome moly tube weighs the same as a mild steel tube.