A solid oil bearing is a standard ball bearing whose internal space is filled with a solid polymer lubricant instead of grease. The polymer holds oil in its structure and releases a thin film to the balls and raceways as the bearing turns. The fill seals the bearing, so it needs no relubrication and does not wash out.
Buyers also call them solid lube bearings, solid lubricant bearings or self-lubricating ball bearings. All of these names describe the same product: a single row deep groove ball bearing sealed with solid oil.
How does the solid polymer lubricant work?
Every bearing we sell starts as a single row deep groove ball bearing made to standard dimensions. In our Glendale, California facility, the free space inside the bearing, around the balls, the cage and the raceways, is filled with Syn-Tech solid oil. The fill then sets solid.
Syn-Tech solid oil is a polymer matrix that holds lubricating oil inside its structure. Picture a sponge made of polymer, saturated with oil, that keeps its shape. As the bearing turns, a thin film of oil migrates from the matrix onto the balls and raceways. The rest of the oil stays locked in the polymer.
Because the lubricant is solid, it cannot run out, drip, separate or be flung off the moving parts. There is no grease fitting, no purge and no relubrication interval to schedule. The bearing arrives lubricated and stays lubricated. You can read more about the process on our how it is made page.
Why is a solid oil bearing already sealed?
With a greased bearing, the buyer chooses between an open bearing, metal shields (marked ZZ or 2Z) and rubber seals (marked 2RS). Each option protects the grease differently.
A solid oil bearing works differently. The polymer fill occupies the space between the inner and outer rings, so the bearing is sealed with solid oil. The fill keeps the lubricant in place and keeps wash water and cleaning chemicals from washing it out. There is no shield or seal option to choose: every size we sell is sealed with solid oil, and it fits anywhere a greased bearing of the same bore, outside diameter and width was used before.
Where are solid oil bearings used?
Solid oil bearings earn their keep anywhere grease is hard to keep in, hard to keep clean or hard to reach. Typical applications include:
- Food and beverage lines, where grease purge is a contamination risk and washdown removes conventional lubricant
- Washdown equipment, conveyors and packaging machinery
- Marine and wet environments, where water finds its way into greased bearings
- Hard-to-reach motors, fans and pumps that nobody wants to climb up to regrease
- Textile machinery, where lint and fibers collect on greased parts
- Agricultural equipment exposed to dust, mud and weather
- Robotics and instruments, using our miniature sizes down to 1 mm bore
The common thread is that the bearing is expected to run without attention. For a side by side comparison, see solid oil vs grease bearings.
When should you not use a solid oil bearing?
Solid oil bearings run at lower maximum speeds than greased bearings, so email us about high-speed applications. Send the shaft speed, the bearing size and a short description of the machine to info@solidoilbearings.com or through the contact form, and we will tell you whether a solid oil bearing is a good fit. We reply within one business day.
Every product in the store is a single row deep groove ball bearing. If your machine uses a tapered roller bearing, a needle bearing, an angular contact bearing or a mounted pillow block unit, we do not have a solid oil version of it.
Standard or Food Grade: which grade do you need?
Every one of our 204 sizes comes in two grades.
- Standard bearings use chrome steel rings and balls. The SKU follows the pattern 6203-SL. Choose Standard for general machinery, motors, fans, pumps, conveyors and wet environments outside food zones.
- Food Grade bearings use stainless steel rings and balls and an NSF H1 registered solid lubricant. The SKU follows the pattern S6203-FGSL. Choose Food Grade for food and beverage equipment, and wherever your plant program calls for H1 lubricants and stainless steel components.
Both grades share the same dimensions, so the choice never affects fit. Our food grade bearings guide covers the differences in more detail.
How do you order a solid oil bearing?
Start with the size. Read the number off the old bearing, or measure the bore, the outside diameter and the width with calipers and enter them in the Bearing Finder. You can also browse all 204 sizes by series: metric 6000, 6200 and 6300 series from 10 to 110 mm bore, thin section 6700, 6800 and 6900 series, miniature sizes, inch R series from R4 to R24, and the inch 1600 series with extended inner race.
Pick Standard or Food Grade and place the order. A few things to know:
- Every bearing is filled to order and ships in 7 to 10 business days by UPS or USPS, within the United States only.
- Standard shipping is a $10 flat rate and free on orders over $100. Express shipping with 3 to 5 day transit is $35.
- There is no minimum order. For quantity pricing, email us.
- Because bearings are filled to order, all sales are final. A wrong or defective item is replaced free if you report it within 48 hours with photos, and an order can be cancelled only before filling starts.
More answers are on our FAQ page, or you can ask us directly through the contact form.
Frequently asked questions
Do solid oil bearings need to be greased?
No. The polymer fill holds the oil the bearing uses and releases it as the bearing turns. There is no grease fitting and no relubrication schedule.
Are solid oil bearings the same size as regular bearings?
Yes. The base bearings are made to standard dimensions, so a 6203-SL has the same bore, outside diameter and width as any other 6203. It drops into the same shaft and housing without changes.
How long does an order take to ship?
Every bearing is filled to order in our Glendale, California facility and ships in 7 to 10 business days by UPS or USPS. Express shipping with 3 to 5 day transit is available for $35.