Free machining materials often yield the fastest speeds and lowest cost to the end user. These alloys often allow for machining quality that is predictable and management, resulting in high quality parts with a quick turnaround. Below is a list of the free machining alloys we most often work with.
The U.S. standard for high machinability. Especially suitable for crimping and knurling applications due to higher lead content.
This popular alloy is often selected for electronic spring contacts due to its high tensile strength. Machines almost as fast as brass.
This high tensile strength alloy is the best machining option of the nickel silver family.
Tough on tools but it creates a highly corrosion resistant part that is equally as tough.
Often chosen for its hardening characteristics after Heat Treat. This alloy can be inconsistent to machine and tough on tools. Machines more like steel rather than a copper based alloy.
This highly conductive material is extremely soft, lowering it’s machineability rating. Popular in electronics and glass to metal applications.
This excellent “free machining” aluminum runs as fast as brass and creates small easy to work with chips.
This very high tensile strength aluminum alloy is more difficult to work with than 2011 due to its tough and long chips.
This aluminum alloy is known for its high strength, solderability and corrosion resistance. Difficult to machine at high speed
This is the best machining alloy of the plastic family.
12L14 is the best machining alloy of the steel group.
This steel can be hardened to Rc 65 and commonly used for shafts and similar applications. It is approximately equal to ASTM A1095.
This tough alloy is commonly used for bearings and other parts requiring high impact resistance.
This is the fastest machining stainless steel , but has a hardening limit of RC 38-42 through heat treatment.
430F is the free machining version of 430. Cannot be hardened by heat treatment.
420F is an excellent choice for a high machining stainless steel. It can be hardened to Rc 52.
This alloy machines well, but slowly. Machine type and part geometry can change this rating dramatically.
This variation of 316L provides a significantly better machining rate and more resistance to corrosion than typical 316 alloys. However, the sulfur content does reduce the weldability compared to standard 316.