12L14 belongs to lead sulfur composite free cutting structural steel. In lead easy to cut steel, lead is distributed as small elemental metal particles in the steel and does not melt in the steel. During the cutting process, 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 fine, reducing tool wear, and ultimately extending tool life.

Compared with steel without lead, the cutting performance of lead containing steel can be improved by 20-50%, while the mechanical and heat treatment properties remain basically unchanged, and it has no effect on cold and hot workability and weldability. Lead free cutting steel has been widely used in the manufacturing of precision instrument parts, automotive parts, and important parts of various machinery. The disadvantage of lead free cutting steel is low contact fatigue, and it is not suitable for components such as gears and bearings that can withstand high fatigue stress loads.

>>Component specifications

12L14 is an American standard steel grade, corresponding to the national standard grade Y15Pb, and the Japanese label number SUM24L.

Brand Y15Pb 12L14 SUM24L

C0.10~0.18≤0.15≤0.15

Si≤0.15（≤0.10）（≤0.10）

Mn0.80~1.200.85~1.150.85~1.15

P0.05~0.100.04~0.090.04~0.09

S0.23~0.330.26~0.350.26~0.35

Pb0.15~0.350.15~0.350.10~0.35

>>Performance Introduction

① 12L14 is essentially low-carbon steel, and due to its low carbon content, its mechanical properties are quite low.

② After processing, the surface smoothness of 12L14 is excellent.

③ 12L14 has excellent cutting performance.

>>Application scope

Mainly used in situations where the force is small but the size and smoothness requirements are strict, such as standard parts used in instruments, watch parts, automobiles, machine tools, and other various machines, such as gears, shafts, bolts, valves, bushings, pins, pipe joints, spring seat cushions and machine screws, plastic forming molds, surgical and dental procedures, etc.