12L14 is a free cutting steel, commonly known as Yiche iron, which belongs to the lead sulfur composite free cutting structural steel.

During the cutting process of 12L14, due to the addition of lead element, strong friction is generated between the tool and the workpiece, causing the lead particles in the steel to precipitate in a molten state, thereby providing lubrication to improve the cutting performance of the steel, making the steel chips finer, reducing tool wear, and ultimately extending tool life.

Executive standard: ASTM A29/A29M-2015/SAE J 403 (2009)

The chemical composition is as follows:

12L14 is mainly used for making instruments, watch parts, automobiles, machine tools, and other various machines with strict requirements for size and smoothness due to low stress. It is used for standard parts with strict requirements for size accuracy and smoothness but relatively low mechanical performance, such as gears, shafts, bolts, valves, bushings, pins, pipe joints, spring seat cushions and machine tool screws, plastic forming molds, surgical and dental surgical tools, etc.

12L14 is usually delivered in the form of hot rolling or cold drawing. From a chemical composition perspective, it is equivalent to the national standard Y15Pb and is not environmentally friendly as it contains lead.