Chromoly Vs Mild Steel Weight

The elongation values of the docol tubes are better than in the 4130 chrom moly tubes.

Chromoly vs mild steel weight.

The docol tubes showed a better behavior at fracture compared to the crmo tubes. Imo the time effort labor side of grinding fitting moly vs mild steel is pretty much a wash in the end. A stronger mild steel rod such as 80s d2 can be used to weld thin walled chromoly without post heat but 70s rod is a better choice for frames as the increased ductility will serve better at absorbing repeated impacts. 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.

And wall thickness a chrome moly tube weighs the same as a mild steel tube. 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. 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. It was designed for and is used extensively in the aircraft industry due to it s high tensile strength and torsional load ratings.

The docol tubes have slightly lower yield strength but higher tensile strength. In conclusion if weight reduction is important in the design of your chopper then chromoly tubing is an excellent choice. One of the never ending topics of conversation is the use of 4130 steel over mild steel in professional drag racing builds. Mild steel with it s thicker wall you don t really want to fit as tight as moly using either a little larger fitted gap or a larger chamfer at the gap to aid heat penetration without cranking up the machine a bunch so less time spent.

Given the same o d. Chromoly is a chrome alloy steel with a medium carbon content and 8 1 1 molybdenum for strength.