Precision Powdered Metal Bearings
As a leading powdered metal bearings manufacturer, we have more than 40 years of experience supplying bearings to the Appliance, Automotive, Lawn & Garden, Tool, and Motor Industries.
Our precision powdered metal bushings and bearings can be found in many applications ranging from control systems to fractional HP Motors. Powdered metal component manufacturing is a great option when your bearing or bushing would benefit from the more even distribution of lubrication throughout and across the working surface or when plastic simply does not meet the strength requirement. Material selections from Bronze to Iron Graphite blends are available to provide the best performance for our customers. Bearings can be impregnated with an oil to increase the life and performance of the assembly.
Benefits of Manufacturing Custom Powder Metal Bearings/Bushings
Manufacturing bearings and bushings with powdered metal provides the opportunity to impregnate the pieces with oil, making supplemental lubrication unnecessary. The addition of internal lubrication to powder metal bearings decreases the friction coefficient, resulting in increased bearing life, extremely low maintenance, and reliable, high performance under load.
Additional benefits of powder metal bearings include meeting tight tolerances, quiet operation, and the capacity for higher volumes. A key benefit of using powdered metal for custom bearings is its cost-effectiveness. The ability to produce pressed metal bearings means that tight tolerances and clean edges eliminate or reduce the need for additional operations. All together results in time and money saved for your application.
With little to no waste, powdered metal is a green process due to its low energy usage and minimal scrap, making it more economical than standard machining or casting. Material selection for powdered metal bearings allows for optimization of the component’s performance for its intended application with little variation in the manufacturing process.
At Atlas Pressed Metals, we specialize in this dynamic process; our team deeply understands more than just metal bearing manufacturing. We also provide a high level of expertise in engineering and the material science surrounding powdered metallurgy. This means that we can recommend metal powders and lubricants that help our customers in designing parts that will optimize performance. When a properly selected material is combined with appropriate process parameters, the result is a bearing that meets the application requirements with proven cost-savings over conventional machining methods.
Applications for Powder Metal Bearings/Bushings
Bearings are used a wide variety of industries and applications as they allow many tools and most equipment to function. Some examples include:
- Windshield wipers
- Power window mechanisms
- Seat adjusters
- Garbage disposals
- Washing machines
- Hand tools
- Space and scientific equipment
- Office furniture
- Construction equipment
Materials Used for Manufacturing Sintered Bushings/Bearings
The powder metallurgy process begins with a collection of metal powder particles.
Metal powders are engineered materials that meet a wide range of performance requirements. Understanding the powder is crucial in powder metallurgy as this is the key input to the production of a final metal component.
The powder is produced through either solid-state reduction, atomization (gas, water, or centrifugal), electrolysis, or chemical treatments of the metallic material.
Atomization is the typical method used today. It involves the conversion of molten metal in a spray of droplets that solidify into powder. Water atomization is the most common form of atomization as it results in irregularly shaped particles, which is beneficial in the compaction of powder metal component production.
Metal powders are classified as elemental, partially-alloyed, or pre-alloyed. Elemental powder is a granular form of pure metal powder. They are the building blocks of creating alloys and composite materials. Partially-alloyed powders are a mixture of elemental powders of different materials blended together, and a prealloyed material is in an alloyed state as produced by atomizing a combination of metals.
In most cases, the powder mixture, whether elemental or prealloyed, also contains additives (lubricants or binders) for increased tool life, to assist in the ejection of the component from the compaction die or to hold the metal part together before the sintering process. These additives are removed from the component desiring the sintering process.
The geometry of the individual powder is defined by particle shape and internal structure, particle size and distribution, and surface area. Particles come in a variety of shapes, from spherical, irregular, flake, dendritic, and sponge. The distribution of particle sizes in the powder influences compaction as smaller particles will fill in the void between larger particles. This combination of sizes improves compaction density and material properties.
These are critical parameters in powder metallurgy as they determine how the powder performs when filling the die, during compaction, and in sintering. These factors must be optimized to achieve the desired strength and density in the green stage and in the final sintered component.
Powder Materials for Bearing Applications
Bronze powder is the most common choice for bearings due to its excellent wear resistance and self-lubricating properties. These materials are made with 12-30% interconnecting porosity to contain the lubricating oil. With a 10% addition of tin, bronze provides corrosion resistance, can be designed to manage shock loading, and provide the necessary ductility to handle staking. Graphite is often added to the mix for improved lubricity. The percentage of graphite, from 1% to 3.5%, used in the mix depends on the component's specific requirements in its application.
Iron or ferrous alloys are harder and stronger than bronze powder. There are several alloys in this category that are designed to address specific component and application requirements. Often these bearings are considered “structural bearings.”
Balancing the requirement of high porosity for lubrication with other operating conditions such as load, temperature, sound, and speed influences the material selection.
Atlas supplies 40 million bearings a year to a variety of industries and applications!
Additional Efficiencies of PM Bearing Manufacturing
Atlas Pressed Metals, a leading custom powdered metal bearing manufacturer, is equipped with a wide range of state-of-the-art automation and material handling systems, adding greater efficiency to an already highly efficient process. We also provide extensive finishing capabilities for bearings; these include machining, sizing, plating, and heat treating. Other finishing options include the impregnation of lubricants, resins, and sealers, as well as standard and specialty coatings.
Onsite equipment used for the manufacture of powder metal bearings and bushings includes a compaction press, sintering furnace, and secondary machine operations if needed.
Additional advantages of the manufacture of powder metal bearings include:
- Economies of scale for mass production
- Repeatability and consistency of required geometry, dimensions, and tolerances
- Better performance of the bearing in its specific assembly
- Use of controlled density or management of porosity per the application requirements
- Self-lubricating if required
- Sound dampening
Custom Powder Metal Bearing Specifications
Our team of skilled engineers has the industry experience and knowledge to guide every stage of your sinter metal bearing requirements – from weight to shape; our flexibility is our expertise.
We have the flexibility to design and manufacture sintered bearings and bushings ranging from, but not limited to:
- Weight: Up to 6800 grams (15 lbs.)
- Diameter: 3mm (0.125”) to 250mm (10”)
- Length: 3mm (0.125”) to 76mm (3”)
- Shapes: structural, spherical, flanged, single to multi-level
Our precise molding capability and manufacturing process allow us to hold tight tolerances for demanding applications.
Understanding Powder Metallurgy
Step One: Collaborative review of your new part design or an evaluation of a potential conversion to powder metal for an existing part
Step Two: Selecting the best powder or powder blend for durability, reliability, and accuracy
Step Three: Compacting the metal powder to precise specifications under controlled pressure
Step Four: Heating or "Sintering" to create a permanent form
125 Tom Mix Dr.
P.O. Box P
DuBois, PA 15801
"After finding Atlas Pressed Metal on the internet and a site visit by our CEO, we were impressed with the Atlas plant, the team and the product. We used them for a powdered metal part for one of our customers and we have continued to use them for about 5 years. We are pleased with their expertise in making good suggestions and with their customer service.”