When you’re involved in industries that rely heavily on machinery, you’ll inevitably encounter the need for a 4 Bolt Flange Bearing. If you’ve been thinking about purchasing these bearings, it’s essential to understand a few key points first.

Breaking Down 4 Bolt Flange Bearings

• What exactly is a 4 bolt flange bearing?: As the name suggests, these are bearings mounted onto a square or round flange, held in place by four bolts. The design allows the bearing to rotate or adjust to the length of the shaft it supports.
• Material of the housing: The housing of these bearings comes in several materials, each with its own unique properties. Cast iron, familiar to anyone who has worked with kitchenware, primarily consists of iron mixed with small amounts of silicon and carbon. The production method affects its characteristics. Pressed steel is a low-carbon steel that is pressed instead of machined. Plastic or thermoplastic materials, including substances like nylon and Teflon, are organic or synthetic compounds that become malleable when heated and brittle when cooled. Stainless steel is resistant to chemicals and corrosion and can handle high-pressure environments.
• Material of the bearing: The type of material used to construct the bearing directly impacts its performance and application. Aluminum is resistant to wear, capable of handling heavy loads, and an excellent heat conductor. It’s commonly used in engine components such as connecting rods and bearings. Steel, which is iron alloyed with carbon (up to 1.7%), is often used in high-carbon steel forms, which are malleable under specific conditions. Steel differs from cast iron due to its lower carbon content. As noted earlier, stainless steel is resistant to chemicals and corrosion and has excellent pressure ratings. Powdered-metal bearings are cost-effective and self-lubricating. These bearings are porous, allowing them to absorb oil, graphite, or PTFE, making them ideal for situations where lubrication is challenging. Graphite-metal alloy bearings are self-lubricating and made by melting graphite with metal. Plastic bearings, as described above, are strong and durable, don’t require lubrication, and can bear significant weight, making them suitable for many applications.
• Applications: We use 4 bolt flange bearings for both rotary and linear motions when the bearing mounting area is perpendicular to the shaft. There are designs with 2, 3, and 4 bolts, with the 4 bolt version being preferable for heavier loads. When choosing a bearing, it’s crucial to consider the size and height of the shaft. The size refers to the maximum diameter of the shaft or the bearing’s diameter, while the height above the mounting area is important if there are clearance limitations.
• Key performance considerations: Speed is a critical factor, determining how fast the bearing can operate before failing. Bearing life is measured by its lifespan at 90% reliability, known as the L10 rating. Bearing loads refer to the radial and thrust forces it needs to withstand. Engineering load describes the forces acting on the shaft supported by the bearing, including the weight of the shaft, belt or pulley stresses, and unbalanced loads. Operating temperature relates 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 using a pump or grease fitting to apply lubricant to the friction areas of the bearing. Self-lubricating bearings either don’t need lubrication due to their composition (like those made from materials like bronze or PTFE) or are manufactured with base metals that naturally absorb oil.

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

If you’d like to discuss 4 bolt flange bearings or any other topics, feel free to reach out to us.