Thin section (6700, 6800, 6900), miniature (60x to 69x, small R sizes) and inch (R4 to R24, 1600 series) solid oil bearings are deep groove ball bearings sealed with solid oil. They fit robotics, instruments, medical devices, small motors, encoders, textile and printing equipment, compact automation, and inch-drawing machinery such as agricultural, lawn and garden and conveyor equipment.
All 204 sizes come in Standard and Food Grade, filled to order in Glendale, California. Here is where each family fits and how to read its part number.
What are thin section bearings, and what do 6700, 6800 and 6900 mean?
A thin section bearing is a deep groove ball bearing with a thin wall, or radial section: half the difference between the outside diameter and the bore. For a 17 mm shaft, a standard 6203 measures 17 x 40 x 12 mm (bore x outside diameter x width). The 6903 measures 17 x 30 x 7 mm, the 6803 17 x 26 x 5 mm and the ultra thin 6703 17 x 23 x 4 mm.
A 6900 series bearing is the first step down from a standard bearing, a 6800 series bearing is thinner and narrower, and a 6700 series bearing is for the tightest radial space. Typical uses: robot joints and grippers, encoders, instrument spindles, medical devices, printing and textile equipment, compact automation. Sealed with solid oil, they are maintenance free thin section ball bearings.
What are miniature bearings and where are they used?
Miniature means the three-digit metric sizes with bores from 1 mm to 9 mm (the 60x, 62x, 63x, 67x, 68x and 69x families) plus the smallest inch R sizes, all in our miniature and instrument bearings collection.
A miniature solid oil bearing suits small motors, encoders, instruments, medical devices, robotics, printing and textile equipment, and compact automation. The 608 (8 x 22 x 7 mm) is a typical example.
Why does solid oil suit small, sealed machinery?
Solid oil is a solid polymer lubricant that holds oil in a matrix and releases a thin film to the balls and raceways as the bearing turns. The fill occupies the free space inside the bearing and seals it. There is no grease to relubricate, purge or wash out.
A miniature bearing holds very little lubricant, and once the device is assembled there is no way to add more. Grease can also migrate or fling out onto an encoder, optics or printed sheet, while solid oil stays in place. Solid oil also survives washdown and cleaning chemicals, which matters for devices cleaned often.
One limit: solid oil bearings run at lower maximum speeds than greased bearings, so email us about high-speed applications. More on the solid oil vs grease page.
What are inch R series and 1600 series bearings used for?
Inch bearings are made to fractional inch dimensions for machines designed to inch drawings. The R series runs from R4 (1/4 inch bore) to R24 (1-1/2 inch bore). The maintenance free R8 bearing (1/2 x 1-1/8 x 5/16 inch) is a widely used size.
The 1600 series has an extended inner race: the inner ring is wider than the outer ring and projects past its faces, so it grips more shaft and can seat against a shoulder while the outer ring stays clear. The 1616 bearing shares the R8's 1/2 inch bore and 1-1/8 inch outside diameter, with a listed width of 3/8 inch.
Both fit agricultural equipment, lawn and garden machinery, conveyors built to inch drawings and OEM replacement, often in dirt and water.
How do I read the size from the part number?
Check the bore first: it must match the shaft exactly. When in doubt, enter bore, outside diameter and width in the Bearing Finder.
Metric four-digit numbers (6700, 6800, 6900, 6000, 6200, 6300)
The first digit, 6, means deep groove ball bearing. The second digit is the series: 7, 8 and 9 are thin sections, 0, 2 and 3 standard sections. The last two digits are the bore code: for 04 and up, multiply by 5 for the bore in millimeters, so 6804 has a 20 mm bore. The exceptions are 00 (10 mm), 01 (12 mm), 02 (15 mm) and 03 (17 mm).
Miniature three-digit numbers (60x to 69x)
The last digit is the bore in millimeters: 608, 628, 638, 688 and 698 all have an 8 mm bore and differ in outside diameter and width. A last digit of 1 means a 1 mm bore, our smallest.
Inch R series (R4 to R24)
The number after the R is the bore in sixteenths of an inch: R4 is 4/16, or 1/4 inch, and R8 is 1/2 inch. The smallest R sizes use their own codes, so check the product page.
Inch 1600 series
The 1600 numbers are catalog codes, not a formula, and several sizes share one outside diameter with different bores, so match all three dimensions from the product listing.
How do I order thin section, miniature and inch bearings?
Every size comes in two grades. Standard: chrome steel rings and balls, part numbers ending in SL (6803-SL). Food Grade: stainless steel rings and balls with an NSF H1 registered solid lubricant, part numbers starting with S and ending in FGSL (S6803-FGSL).
Every bearing is filled to order and ships in 7 to 10 business days by UPS or USPS within the United States. For quantity pricing, email info@solidoilbearings.com with the part number, grade and quantity (no minimum order). Fit questions go to the same address or the contact form, answered within one business day.
Frequently asked questions
Is a 6800 series bearing interchangeable with a 6000 or 6200 series bearing?
No. Both fit a 17 mm shaft, but the 6803 is 26 mm across and 5 mm wide while the 6203 is 40 mm across and 12 mm wide. Match all three dimensions.
Do miniature solid oil bearings need relubrication?
No. The bearing is filled with solid oil once, and the polymer releases a thin film of oil as it turns. There is nothing to add, purge or top up.
Can I replace an R8 with a 1616?
Only if the shaft and housing allow it. Both have a 1/2 inch bore and 1-1/8 inch outside diameter, but the 1616 has an extended inner race and a 3/8 inch listed width against 5/16 inch for the R8. Check the drawing first.