The right hanger bearing is essential for reliable screw conveyor performance, reducing vibration, extending bearing life, and keeping material flow smooth. This guide highlights top pillow block bearings designed for normal-duty service, featuring robust cast-iron housings, relubricatable seals, and solid one-piece housings. We evaluate five Sealmaster NP-series units, known for ready-to-mount installation and durable load handling, plus a practical hardware accessory for wood and furniture projects that illustrates common hanger hardware usage. Use the comparison below to help select the best option for your conveyor’s shaft size and load conditions.
| Product | Bore (in) | Base To Center Height (in) | Bolt Hole Width (in) | Key Feature | Amazon Link |
|---|---|---|---|---|---|
| Sealmaster NP-16 | 1 | 1-7/16 | 4-1/8 | Relubricatable, two-bolt housing | View |
| Sealmaster NP-24 | 1-1/2 | 1-15/16 | 5-3/8 | Cast iron housing, robust for radial loads | View |
| Sealmaster NP-19 | 1-3/16 | 1-11/16 | 4-3/4 | Solid one-piece pillow block | View |
| Sealmaster NP-20 | 1-1/4 | 1-7/8 | 5 | Ready-to-mount, two-bolt design | View |
| Sealmaster NP-12 | 3/4 | 1-5/16 | 3-3/4 | Compact, versatile | View |
Sealmaster NP-16 Pillow Block Bearing
The NP-16 is a non-expansion, normal-duty pillow block with a 1″ bore and a solid two-bolt housing that accommodates ready-to-mount installation. Its cast-iron housing and steel bearing unit support radial loads and, when needed, thrust loads. A relubricatable, solid, one-piece housing minimizes play and maximizes rigidity, ensuring smooth operation for screw conveyors with moderate duty cycles. This unit is designed for straightforward maintenance and dependable service life in typical industrial settings.
Sealmaster NP-24 Pillow Block Bearing
The NP-24 features a 1-1/2″ bore and a base-to-center height of approximately 1-15/16″, with a 5-3/8″ bolt hole spacing. The larger bore and taller base provide improved alignment options for heavier screw conveyors or those carrying higher radial loads. Like other NP-series units, it uses a cast-iron housing with a relubricatable, solid one-piece construction to maximize strength and rigidity, yielding reliable performance in demanding environments.
Sealmaster NP-19 Pillow Block Bearing
The NP-19 provides a 1-3/16″ bore and a base-to-center height of 1-11/16″, with a 4-3/4″ bolt hole spacing. This size balances compact footprint with adequate seating for moderate-duty conveyors. The two-bolt housing and relubricatable design maintain alignment and reduce maintenance downtime, making this model a practical choice for conveyors requiring dependable bearing support without excessive bulk.
Sealmaster NP-20 Pillow Block Bearing
With a 1-1/4″ bore and a base-to-center height of 1-7/8″, the NP-20 offers a 5″ bolt hole spacing width. It is designed for straightforward mounting, durable load-carrying capability, and ease of maintenance. The combination of cast-iron housing and a relubricatable bearing unit provides reliable support for screw conveyors involving medium-duty operation and frequent cycle movement.
Sealmaster NP-12 Pillow Block Bearing
The NP-12 is the compact option with a 3/4″ bore and a base-to-center height of 1-5/16″, plus a 3-3/4″ bolt hole width. Its small footprint makes it suitable for tight conveyor layouts or lighter-duty screw conveyors. As with the other NP-series units, it provides a reliable relubricatable, solid housing to maintain alignment and reduce vibration in continuous operation.
Buying Guide: Key Considerations For Hanger Bearings on Screw Conveyors
Choosing the right hanger bearing for a screw conveyor involves assessing load, speed, alignment, and maintenance needs. The following points offer a balanced, multi-perspective view to help you compare options objectively.
- Load capacity and duty cycle: For high-throughput or long conveyors, prioritize larger bore sizes and taller base-to-center heights to improve stability and accommodate heavier radial and thrust loads. NP-series models cover a broad range of loads while preserving a compact form.
- Mounting and alignment: Two-bolt housings simplify installation and alignment. Ensure bore size matches your shaft diameter, and confirm center height accommodates existing supports and belt or chain drives adjacent to the conveyor.
- Material and construction: Cast-iron housings offer rigidity and durability under vibration. If your environment involves corrosive elements, consider coatings or alternative materials if compatible with the system.
- Seals and lubrication: Regreasable designs extend service intervals. Check seal integrity (felt seals, double-lip seals) to minimize contamination, especially in dusty or humid settings.
- Maintenance access: Bolted covers or relubrication ports should be accessible without disassembling the conveyor system. Plan for routine lubrication intervals to maximize bearing life.
- Footprint and compatibility: Compare bolt hole spacing and base-to-center height to your existing mounting pattern. A slightly larger unit can improve life if space permits, but fitment must be exact to prevent misalignment.
- Availability and service: Availability of replacements and quick shipping matter in maintenance windows. Established brands with broad product lines typically offer faster replacements and better technical support.
When selecting, align your choice with the specific screw conveyor’s shaft diameter, load expectations, and operating environment. For many standard industrial applications, NP-series pillow blocks provide a reliable balance of durability, ease of installation, and maintenance accessibility, making them a common recommendation.