Marine Grade Stainless Steel Bearings – 304 & 316 Corrosion Resistant Solutions
Ensure smooth operation and extended service life in harsh maritime environments with All-K Marine Stainless Steel Bearings. Engineered from premium AISI 316 and 304 stainless steel, these bearings offer exceptional resistance to saltwater corrosion, chemical exposure, and high humidity. Ideal for winches, deck cranes, water pumps, steering systems, and offshore machinery.
Product Overview
Standard chrome steel bearings rapidly fail in marine settings due to rust and pitting. The Stainless Steel Bearing series from All-K Marine eliminates this risk. Constructed entirely from marine-grade stainless steel (rings, balls, and cages), our bearings are designed to withstand direct saltwater spray and submersion without compromising structural integrity.
We offer both Full Stainless Steel configurations and Hybrid Ceramic options (Stainless rings with Silicon Nitride balls) for applications requiring higher speeds, lower friction, and electrical insulation. Available in Deep Groove, Self-Aligning, Thrust, and Pillow Block styles to fit any marine application.
For any component exposed to seawater, AISI 316 is the industry standard. Its molybdenum content provides superior resistance to chlorides compared to 304 grade, preventing crevice corrosion and ensuring reliable performance in critical shipboard systems.
Key Features & Advantages
- Maximum Corrosion Resistance: Made from AISI 316L or 304 stainless steel, offering outstanding protection against rust, salt spray, and acidic/alkaline chemicals found in marine and offshore environments.
- Hybrid Ceramic Options: Optional silicon nitride (Si3N4) ceramic balls reduce weight by 40%, increase speed limits, eliminate sparking, and provide electrical insulation while maintaining corrosion resistance.
- Advanced Sealing Technology: Equipped with high-quality 2RS (non-contact rubber seals) or ZZ (metal shields) to keep contaminants out and grease in, even under high-pressure washdowns.
- High Load & Durability: Precision-ground races and hardened stainless balls ensure high radial and axial load capacities, matching or exceeding standard chrome steel performance in wet conditions.
- Low Maintenance: Pre-lubricated with marine-grade grease suitable for wide temperature ranges, reducing the frequency of re-lubrication and downtime.
- Versatile Configurations: Available in metric and inch sizes, including single row, double row, self-aligning, and thrust bearing designs.
Material Comparison: Select the Right Grade
AISI 304 Stainless Steel
Best For: Interior marine applications, dry deck areas, food processing equipment on ships, and environments with mild humidity.
Properties: Good general corrosion resistance, cost-effective, non-magnetic (mostly).
AISI 316/316L Stainless Steel
Best For: Exterior deck machinery, submerged components, offshore platforms, and areas directly exposed to saltwater spray.
Properties: Superior chloride resistance due to Molybdenum content, essential for harsh marine survival.
Hybrid Ceramic (SS Rings + Si3N4 Balls)
Best For: High-speed winches, electric motors, pumps requiring electrical insulation, and extreme temperature variations.
Properties: Lowest friction, highest speed rating, non-conductive, zero rust on balls.
Technical Specifications
| Bearing Type | Deep Groove Ball, Self-Aligning, Angular Contact, Thrust, Pillow Block Units |
|---|---|
| Ring Material | AISI 304, AISI 316, AISI 316L Stainless Steel |
| Ball Material | Stainless Steel 316, Silicon Nitride (Si3N4) Ceramic |
| Cage Material | Stainless Steel, PTFE (Teflon), Polyamide (PA66) |
| Seal/Shield | 2RS (Rubber Contact Seal), ZZ (Metal Non-Contact Shield), Open |
| Precision Class | ABEC-1 (P0), ABEC-3 (P6), ABEC-5 (P5), ABEC-7 (P4) |
| Clearance | C2, C3 (Standard for Marine), C4, C5 |
| Lubrication | Marine Grade Grease (Food Safe options available) |
| Temperature Range | -40°C to +120°C (Standard), up to +300°C (High Temp variants) |
| Standards | ISO 15243, DIN 625, JIS B 1530, ANSI/ABMA Std 20 |
Primary Applications
Our stainless steel bearings are critical components in:
- Deck Machinery: Winches, windlasses, capstans, and cranes where salt exposure is constant.
- Propulsion & Steering: Rudder stocks, steering gears, and propeller shaft supports.
- Pumps & Motors: Seawater cooling pumps, bilge pumps, and electric thruster motors.
- Offshore Equipment: Drill rig components, ROV manipulators, and subsea valves.
- Fishing Industry: Net haulers, reel systems, and processing conveyor belts.
- Yacht Fittings: Sail track rollers, sheet blocks, and navigation instrument mounts.
Frequently Asked Questions (FAQ)
Generally, stainless steel has a slightly lower load rating than hardened chrome steel due to material hardness differences. However, our marine-grade stainless bearings are heat-treated to optimize hardness. For most marine applications, they provide sufficient load capacity. If maximum load is critical, we recommend our Hybrid Ceramic option, which combines stainless rings with ultra-hard ceramic balls for superior performance.
2RS indicates dual rubber contact seals, offering the best protection against water, dust, and salt ingress, making them ideal for wet marine environments. ZZ indicates dual metal shields, which offer less friction and higher speed capability but provide minimal protection against liquids. For deck and underwater applications, 2RS is strongly recommended.
Austenitic stainless steels like 304 and 316 are generally non-magnetic in their annealed state. However, cold working during the manufacturing of bearing rings can induce slight magnetism. If strict non-magnetic properties are required (e.g., for mine-sweeping vessels or sensitive instruments), please specify, and we can provide solution-annealed bearings or hybrid ceramic options with minimal magnetic signature.
Yes, we offer complete stainless steel pillow block units (insert bearings + housing). The housings are available in cast 316 stainless steel or high-grade engineering plastics, perfect for mounting on ship railings, frames, and wet structures.
Request a Quote for Your Vessel or Project
Don’t let bearing failure stop your operations. Upgrade to All-K Marine’s corrosion-resistant stainless steel solutions. We offer custom sizing, bulk pricing for shipyards, and fast global shipping.
Contact our technical sales team: Get a Quote or email [admin@all-kmarine.com.cn].
