If you work with heavy machinery, chances are you’ve encountered the need for a 4-Bolt Flange Bearing. These components play a critical role in supporting shafts and ensuring smooth operation in industrial settings. If you’re considering purchasing 4-bolt flange bearings, there are several key factors you should understand before making your decision.

A Closer Look at 4-Bolt Flange Bearings

• What exactly are 4-bolt flange bearings?: As the name suggests, these bearings are mounted onto a square or circular flange and secured using four bolts. Their primary function is to allow rotational or linear movement while accommodating the length of the shaft they support. The design ensures stability and durability, especially under heavy loads.
• Material options for the housing: The material used for the bearing housing significantly impacts its performance and longevity. Cast iron, commonly found in kitchenware like frying pans, is composed mainly of iron with small amounts of silicon and carbon. The production process influences its properties. Pressed steel, made from low-carbon steel, is formed through pressing rather than machining. Plastic or thermoplastic materials, such as nylon and Teflon, are organic or synthetic substances that become malleable when heated and brittle when cooled. Stainless steel is prized for its resistance to chemicals and corrosion, along with its high-pressure tolerance.
• Materials used for the bearing itself: The choice of material directly affects the bearing’s performance and suitability for specific applications. Aluminum is highly resistant to wear, capable of handling heavy loads, and an excellent heat conductor. It’s widely used in internal combustion engine components like connecting rods and bearings. Steel, which contains iron alloyed with carbon (up to 1.7%), is often used in high-carbon forms that are malleable under certain conditions. Unlike cast iron, steel has a lower carbon content. Stainless steel is known for its chemical resistance and high-pressure capabilities. Powdered-metal bearings are cost-effective and self-lubricating, made from porous bronze and copper alloys that can absorb oil, graphite, or PTFE. While they’re not ideal for heavy-duty applications, they excel in situations where lubrication is a concern. Graphite-metal alloy bearings are self-lubricating and created by melting graphite and metal together. Plastic bearings, as described earlier, offer high strength and molecular weight, eliminating the need for lubrication and making them suitable for numerous applications.
• Applications: We use 4-bolt flange bearings primarily for rotary or linear movements when the mounting area is perpendicular to the shaft. Available in 2-, 3-, and 4-bolt configurations, the 4-bolt design is ideal for heavier loads. When choosing a bearing, it’s essential to consider the shaft’s size and height. The shaft’s maximum diameter or the bearing’s diameter determines its size, while the height above the mounting area becomes crucial if clearance is limited.
• Key performance considerations: Speed is a critical factor—how fast can the bearing operate before failure occurs? Bearing life refers to the lifespan during which the bearing maintains 90% reliability, measured as an L10 rating. Bearing loads involve the radial and thrust forces the bearing must endure. Engineering load describes the forces acting on the supported shaft, including the weight of the shaft itself, belt or pulley tension, and unbalanced loads. Operating temperature pertains to the bearing cage, seal, and grease functioning at elevated temperatures.
• Lubrication needs: All ball bearings require lubrication, whether manually applied or self-lubricating. Manual lubrication involves pumps or grease fittings to ensure proper lubrication of friction-prone areas. Self-lubricating bearings either eliminate the need for external lubrication due to their composition (like those made from materials like bronze or PTFE) or rely on base metals that naturally absorb oil during manufacturing.

For further insights into different bearing types, check out the article “What’s the Difference Between Bearings?” on Machine Design.

Feel free to reach out to us with any questions or additional inquiries regarding 4-bolt flange bearings or other topics.