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The Ultimate Bearing Housing Guide: What It Is & Why It Matters

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May 16, 2025
By Central Surplus

When it comes to keeping machinery running smoothly, bearing housings often go unnoticed — but they play a vital role in industrial performance. 

These components serve as the secure framework that supports and protects a bearing, aligning it with the shaft and distributing loads efficiently. Whether you’re dealing with insert bearings, pillow blocks, or complex shaft assemblies, a well-designed housing is essential for reliable performance and long-term durability.

At their core, bearing housings do more than just hold the bearing — they reduce maintenance, protect against contaminants, and ensure that grease or lubricant stays where it needs to be. And with such a wide variety of styles, metals, and mounting methods available, choosing the right one can significantly impact your equipment’s lifespan and efficiency.

In this guide, we’ll break down the types of housings, what bearings fit inside them, the metals used, and sealing options — all with the goal of helping you find the perfect solution for your operation. Plus, discover why Central Surplus’s expansive inventory is the go-to hub trusted by professionals for sourcing all kinds of bearing housings. 

5 Key Considerations for Choosing the Right Bearing Housing

Not all bearing housings are created equal. Choosing the wrong one can lead to premature failure, costly downtime, and safety risks. Below are five critical factors to keep in mind when selecting a bearing housing that fits both your application and environment:

1. Load Capacity

Start with a clear understanding of the mechanical loads your system will place on the bearing housing — including both radial and axial loads. Higher-capacity housings are typically made from durable materials like cast iron or steel, and are designed to distribute pressure evenly across the bearing insert. If your equipment involves heavy loads or shock, overspec the housing slightly to avoid long-term stress and fatigue.

2. Speed Requirement

Operating speed has a direct effect on bearing selection, lubrication needs, and housing type. At high speeds, even small imbalances can lead to vibration, friction, and heat buildup. Look for housings that can accommodate high-speed applications by ensuring proper alignment, thermal dissipation, and dynamic load support.

3. Lubrication

A good housing doesn’t just hold a bearing — it helps retain lubrication and prevent it from leaking or becoming contaminated. Some housings include built-in grease fittings or allow for easy relubrication intervals.

Others feature internal channels designed to circulate lubricant efficiently. Think about whether your operation will use an oil bath, sealed grease, or another method.

4. Operating Environment

Harsh environments — including those with dust, chemicals, moisture, or vibration — require specialized housings with sealing solutions that protect the bearing. In food processing, for instance, stainless or polymer housings are popular for their resistance to corrosion. In mining, flanged cast iron or taconite-sealed housings offer better protection from debris.

5. Mounting & Compatibility

Consider the shaft size, the style of mounting (e.g. flange, adapter sleeve, or cylindrical mounting), and how the housing fits with your existing equipment. Some applications demand adjustable or self-aligning units like take-up housings, while others benefit from set screw or eccentric collar locking methods for stability.

What Types of Bearings Can You Use Inside a Housing?

A bearing housing is only as effective as the bearing it supports — and not every bearing fits every housing. Below are the 9 most common bearing types used inside housings, along with what makes each one uniquely suited for different loads, speeds, and applications.

1. Self Aligning Ball Bearing: Designed to compensate for shaft misalignment, these bearings are ideal for systems where perfect mounting isn’t guaranteed. They reduce friction and wear, even when loads are uneven or installation isn’t perfectly centered.

2. Spherical Roller Bearing: Built to handle heavy radial loads and moderate axial forces, this bearing is commonly housed in cast iron or ductile iron blocks. It performs well in demanding environments like mining, steel mills, or conveyors.

3. Tapered Roller Bearing: These bearings excel in managing combined axial & radial loads, particularly in high-load or high-speed environments. They’re often mounted inside housings that allow for axial adjustment, preload, and precise shaft alignment.

4. Cylindrical Roller Bearing: Cylindrical rollers provide a larger contact surface than ball bearings, making them a top pick for high radial load applications. They require solid support from housings to maintain rigidity and minimize deflection.

5. Insert Bearing: Frequently used in pillow block or flanged housings, this bearing type is easy to install and replace. It’s designed for medium-load applications and supports both rotational motion and light axial stress.

6. Shaft Bearing: A general term for bearings that support rotating shafts, these can take many forms — from plain bearings to rolling element types. When housed properly, they ensure minimal vibration and smooth operation.

7. Pillow Block Bearing: This is both a housing style and bearing type. Pillow blocks feature a mounted insert bearing, often with set screw or eccentric locking, and are ideal for supporting rotating shafts on flat surfaces.

8. Take Up Bearing: Used in sliding mounts or tension-adjustable assemblies, these bearings allow for movement along a guide slot. They’re perfect for conveyor systems or situations where belt/chain tension needs to be adjusted on the fly.

9. Ball Bearings: The most versatile option, ball bearings are used inside all kinds of housings — from basic flanges to precision-machined housings in motors, fans, and pumps. They’re compact, affordable & easy to replace.

Find the Right Bearing Housing – Without the Wait

Need a specific housing style, size, or material? 

Central Surplus stocks thousands of industrial bearing housings — including pillow block, flanged, mounted units and  take-up housings — from trusted brands like Timken, NTN, and SKF. Every item ships fast, and our inventory is priced competitively for teams who don’t have time (or budget) to waste.

Browse our eBay store now to find the bearing housing that fits your application — and get it shipped out the same day, with next-day delivery options!

Don’t see the exact housing component you’re looking for? 

No problem – our dedicated support team is here to help you source even the most obscure parts. Swap hassle for helpful – reach out to our team to find the part you need.

7 Metals Used in Bearing Housings & Importance of Each

The material of a bearing housing directly impacts its performance, durability, and resistance to environmental factors. Whether you’re prioritizing strength, corrosion resistance, or cost-effectiveness, here’s a breakdown of the 7 most common metals (and materials) used in bearing housings — and why they matter.

  1. Cast Iron: The go-to material for most standard industrial bearing housings, cast iron offers a solid balance of strength, vibration damping, and affordability. It works well in moderate load conditions and can be used with a wide variety of bearing types.
  2. Cast Steel: For applications requiring higher load capacity or greater toughness, cast steel is a superior option. It’s less brittle than cast iron and better suited to environments where sudden impacts or heavy stress are common.
  3. Stainless Steel: When corrosion resistance is essential — such as in food processing, marine, or chemical environments — stainless steel housings shine. They also pair well with sealed bearings to protect against moisture and contaminants.
  4. Pressed Steel: Lightweight and cost-effective, pressed steel housings are often used in lower-load or compact assemblies. While not as rugged as cast options, they can offer sufficient performance in light-duty applications where space and cost are primary concerns.
  5. Ductile Iron: A stronger, more flexible alternative to cast iron, ductile iron combines tensile strength with resistance to cracking. It performs well under dynamic or variable loading conditions and is commonly used in flange and take-up housings.
  6. Polymer: For lightweight or chemically aggressive environments, polymer housings offer impressive resistance to corrosion and are often FDA-compliant. These are ideal when you need a maintenance-free or non-metallic option.
  7. Malleable Iron: Offering a blend of strength and machinability, malleable iron housings are suitable for specialized industrial applications. They’re often used when custom modifications, such as additional ports or mounts, are required.

6 Styles of Bearing Housings & Uses for Each

Bearing housings aren’t one-size-fits-all. The style of housing you choose depends on your mounting surface, shaft direction, space constraints, and alignment needs. Below are the 6 most common bearing housing styles & 8 locking mechanisms, along with where and why they’re used.

  1. Pillow Block Housings (Plummer Blocks):
  • Design: These are arguably the most common type, featuring a pedestal or base with a mounting surface for the bearing. They often have a split design (upper and lower halves) for easy installation and maintenance, especially for larger sizes. They are typically made from cast iron but can also be found in cast steel or other materials.   
  • Applications: Widely used in conveyor systems, agricultural machinery, general industrial equipment, and applications with moderate to heavy loads.
  • Advantages: Easy to install, versatile, and can accommodate various bearing types, particularly self-aligning and spherical roller bearings. Split designs simplify maintenance.
  1. Flanged Housings:
  • Design: These housings have a flat surface (flange) with holes for bolting directly to a machine frame, wall, or other flat surfaces. They come in various shapes like round, square, oval, and triangular.
  • Applications: Commonly used in pumps, motors, gearboxes, and applications where space is limited or where precise alignment against a surface is required.
  • Advantages: Provide a secure and rigid mount, suitable for applications where a pillow block base isn’t ideal.   
  1. Take-Up Housings:
  • Design: These housings are designed to allow for adjustment of the bearing position along a frame or rail. They typically have a slot or track for movement and a mechanism (like a screw) for tensioning belts or chains.   
  • Applications: Primarily used in conveyor systems, belt tensioning mechanisms, and applications where adjustable shaft positioning is needed.
  • Advantages: Facilitate easy adjustment of belt or chain tension, simplifying maintenance and ensuring proper operation.   
  1. Cartridge Housings:
  • Design: These are compact, self-contained units that often include the bearing and seals within the housing. They are designed for easy installation and replacement.
  • Applications: Commonly found in agricultural equipment, construction machinery, and other applications where a compact and protected bearing unit is required.
  • Advantages: Easy to install and replace, offer good protection against contamination.
  1. Hanger Housings:
  • Design: These housings are designed to be suspended from a support structure, allowing for vertical or angled mounting of shafts.
  • Applications: Used in screw conveyors, grain handling equipment, and other applications where overhead support of a rotating shaft is necessary.
  • Advantages: Enable vertical or angled mounting, saving space in certain layouts.
  1. Split Plummer Block Housings (Heavy Duty):
  • Design: Similar to standard pillow blocks but designed for very heavy loads and demanding applications. They are robustly constructed and often feature multiple bolt fixings.
  • Applications: Used in heavy machinery, mining equipment, steel mills, paper mills, and other severe-duty industries.
  • Advantages: Provide very strong support for large bearings under high loads, with split designs aiding maintenance.

Various locking mechanisms are used in bearing housings to secure the bearing to the shaft, each suited for specific applications:

  1. Set Screw: A popular choice for locking insert bearings to the shaft, set screw housings offer a secure grip without requiring additional components. They’re easy to install and ideal for moderate-speed, low-vibration applications.
  2. Eccentric: Eccentric locking collars provide firm shaft engagement by rotating the collar to lock it in place. They’re especially useful in equipment that operates in dusty or contaminated environments, since they help prevent slippage over time.
  3. Taper Adapter Sleeve: This mounting style allows for flexible shaft fitment and easy installation or removal. By adjusting the taper sleeve, users can fit the bearing to various shaft diameters without machining the shaft — saving both time and labor.
  4. Double Concentric: Designed to ensure true concentric rotation, this style enhances stability and reduces vibration at higher speeds. It’s commonly used in systems with tight balance requirements, such as precision fans and motors.
  5. Double Clamp Rings: Ideal for heavier loads or conditions with repeated shock and vibration, double clamp ring housings provide extra axial holding strength. These are often found in mining and aggregate operations.
  6. Adapter Sleeve: Often confused with taper sleeves, adapter sleeves are more standardized and frequently used with spherical roller bearings. They help meet a wide variety of shaft sizes without requiring customized housings.
  7. Concentric: Concentric locking mechanisms offer even force distribution around the shaft, minimizing distortion and shaft damage. They’re well-suited for high-speed or high-precision applications where even a small imbalance can affect performance.
  8. Cylindrical Mounting: This mounting configuration allows the bearing housing to seat into a cylindrical bore or recess, often in cartridge or split housings. It’s useful when the bearing needs to be fully enclosed for added protection or compact integration.

9 Common Sealing Types of Bearing Housings

Seals are your first line of defense against dust, moisture, and other contaminants. Choosing the right sealing solution for your bearing housing ensures longer life, reduced grease loss, and lower maintenance costs. Below are 9 common seal types and where they work best:

  1. Single-Lip: A simple yet effective option for light-duty applications, the single-lip seal provides a basic barrier against particles and splash. It’s best suited for clean, dry environments with minimal exposure to debris or fluid.
  2. Labyrinth: Designed to create a non-contact, multi-path seal, labyrinth types are ideal for high-speed machinery where friction and heat must be minimized. They work well in dusty environments and can be combined with grease packs for extra protection.
  3. Three-Element with Flinger: This style combines multiple sealing layers with a rotating flinger that actively deflects contaminants. It’s often used in agriculture, mining, and other heavy-duty settings where water, mud, or slurry is present.
  4. Tri-Ply: The tri-ply seal features three layers of protection, typically combining contact and non-contact elements. It’s a solid choice for systems where varying contaminants — such as fine dust or moisture — are frequent.
  5. Triple-Lip: A high-contact sealing option, triple-lip designs use multiple tight interfaces to keep grease in and contaminants out. While it may add a bit of friction, it’s excellent for harsh conditions and grease-retention applications.
  6. Taconite: Built for the dirtiest, most rugged jobs, taconite seals combine labyrinth, grease purge, and metal shielding. These are ideal for mining, bulk material handling, and any place where the bearing faces relentless contamination.
  7. Timken Guard: A proprietary sealing solution from Timken, this system includes smart design elements for extended bearing life. It’s engineered to handle variable loads and maintain performance in fluctuating environments.
  8. Double-Lip: The double-lip seal provides more protection than a single-lip without the full resistance of a triple-lip. It’s ideal for moderate contamination levels where balancing protection with efficiency is important.
  9. VR Seal: A versatile option for a wide variety of shaft diameters, VR seals offer strong resistance against dirt, water, and oil. Their flexible design makes them popular in automotive and industrial applications alike.

Make the Smart Move: Choose the Right Bearing Housing with Confidence

Whether you’re replacing a worn-out housing or building a new system from scratch, the right bearing housing is more than just a support frame — it’s a critical part of your machine’s reliability, efficiency & lifespan. 

From cast iron pillow blocks to sealed stainless units, understanding your options gives you the power to reduce downtime, avoid failure, and get better performance from your equipment.

Need help finding the right fit? 

At Central Surplus, our vast inventory includes insert-ready housings, pillow blocks, and specialty mounting styles — all backed by fast shipping, fair pricing, and knowledgeable support. 

Don’t settle for a guess. Choose the bearing housing solution that gets the job done right.