Bronze 841

Bronze 841 in CNC Machining

Bronze 841, also known as C84100, is a leaded tin bronze that contains copper, tin, and lead as its main components.

It is a unique powdered metal used in bearings. Unlike most cast or wrought materials, powdered metals are initially cast and then ground into powder. This powder is mixed with oil and a binding agent and then compressed under high heat to form a shape, usually a round rod or hollow bar. Approximately 19% of the material’s volume is SAE 30 weight oil. As the machine with this bearing starts running and warms up, a thin layer of oil emerges from the bearing, coating the shaft for self-lubrication. When the machine is turned off and the bearing cools, capillary action within the bearing pulls the oil back into the metal.

This material is highly machinable, thanks to its lead content, which produces fine chips during machining. This leads to longer tool life and smoother finishes on machined surfaces. It is ideal for CNC machining, including processes like turning, milling, and drilling. Additionally, bronze, in general, offers good corrosion resistance. Our unique blending and sintering process creates a consistent grain structure and spherical pores in the material. This leads to increased strength, reduced friction, and a uniform oil coating on the shaft. Oil-infused bronzes demonstrate excellent wear resistance and durability when regular lubrication is challenging or impossible.

What is Bronze 841?

Bronze 841 is an oil-impregnated bronze that contains SAE 30 oil, so it is self-lubricating and doesn’t require maintenance. They are made using powder metallurgy, forming interconnected pores that act as a lubricant reservoir. When the shaft rotates, a slight temperature increase and applied load cause oil to flow to the bushing surface. This happens because the oil expands more than the metal. When the shaft stops rotating, the oil is re-absorbed into the porous reservoir.

Bronze 841 is composed of Cu (copper) ranging from 87.5% to 90.5%, Sn (tin) between 9.5% and 10.5%, Fe (iron) not exceeding 1.0%, and P (phosphorus) not surpassing 1.75%. This material is designed for use in applications with medium speed and heavy loads, and it can function at a maximum temperature of 250 ℃. It is insensitive to deflection, has uniform bearing capacity under shaft force, and can withstand radial loads simultaneously. Bronze 841, an alloy of copper, has good electrical conductivity, resistance to heating, ensuring safety, and strong fatigue resistance.