A dental handpiece spins its bur at roughly 200,000 to 400,000 rpm on ball bearings, according to U.S. patent records. Some of those balls are only about one millimeter across. Bearings do most of their work out of sight, in places few people would guess. They sit inside satellites, wind turbines, earthquake-resistant building foundations, and the International Space Station’s water recycling system. Each bearing application demands something different from the part.
This guide explores the most surprising places bearings are used, the smallest and largest bearings on record, and how to match a bearing to the job.
Bearings support rotating or moving parts and reduce friction between them and their holders. Any shaft, wheel, or joint that turns under load typically has one.
Rolling element bearings do this with balls or rollers set between two rings. Our guide to 23 types of bearings covers the designs in detail. The examples below show the range.
A typical wind turbine has more than a dozen bearings, according to the Society of Tribologists and Lubrication Engineers. They support the main shaft, gearbox, and generator. Loads change with every gust. Bearings and gearboxes are designed and certified to last at least 20 years, yet only a small percentage survive that long in the field.
The numbers show how hard that job is. In NREL’s Gearbox Reliability Database, 76 percent of gearboxes failed due to bearings. NREL research found much of that failure happens in as little as 5 to 20 percent of a bearing’s design life. The Department of Energy lists gearbox bearing cracking (often driven by White Etching Cracks or WECs) and premature main bearing wear as leading drivers of wind plant maintenance costs.
One Timken materials specialist in the same article names preloaded tapered roller bearings as a design trend. They make roller skidding and load control easier.
Inside the station’s water recycling system, a centrifuge turns on deep groove ball bearings made from a nickel-titanium alloy called 60NiTi. NASA Glenn engineers chose it for a highly corrosive, lightly loaded, low-speed job.
NASA describes the alloy as hard, corrosion-resistant, and highly resistant to shock loads. It calls that combination unique among bearing materials. A separate NASA report describes 50 mm bore deep groove ball bearings made from 60NiTi for the station’s distillation centrifuge.
Spacecraft turn and point using reaction wheels, flywheels spun by electric motors. Speeding a wheel up or slowing it down rotates the spacecraft without burning thruster fuel. NASA’s guidance and control engineers note that the wheel suspension is almost exclusively lubricated ball bearings.
Those bearings can end a mission. When NASA’s Kepler telescope lost its second reaction wheel in 2013, the mission team pointed to a likely structural failure of the wheel bearing. Reaction wheels typically spin at 1,000 to 4,000 rpm, according to Nature.
Heavy-duty bulk handling conveyors rely on mounted spherical roller bearings housed in pillow blocks or flange units. These applications must withstand intense radial shock loads, severe misalignment caused by belt tension or frame flex, and abrasive airborne dust. Specialized labyrinth seals and heavy greasing purge points keep contaminants from entering the rolling elements.
Roll necks in hot-rolling steel mills carry continuous multi-ton loads at elevated operating temperatures. Multi-row tapered roller bearings and cylindrical roller bearings absorb extreme radial and axial forces while enduring high thermal expansion, steam, and synthetic coolant exposure. Specialty synthetic greases or oil mist lubrication systems prevent catastrophic thermal breakdown during continuous production runs.
Air-driven dental turbines run small ball bearings at extreme speed. One patent record puts ball bearing turbine handpieces at roughly 200,000 to 400,000 rpm. The filing notes the bearing unit runs hot, sees large stress, and must survive repeated autoclave sterilization.
Few jobs combine speed, heat, and cleaning cycles in such a small package.
The standard skateboard bearing is the 608, a miniature deep groove ball bearing. It has an 8 mm bore, a 22 mm outside diameter, and a 7 mm width. Each wheel takes two, so a board carries eight.
Shoppers see ABEC ratings on the package. These classes describe manufacturing tolerance, and higher numbers mean tighter tolerances. Our bearing tolerances guide explains how ABEC classes line up with ISO grades.
Base-isolated buildings sit on seismic isolation bearings that let the ground move while the structure above moves far less. These are not the ball bearings in a motor. The Society of Engineers notes elastomeric bearings, layers of rubber and steel, are the most common type.
Friction pendulum bearings are another option. They slide on a curved surface, and Apple’s headquarters in California is reportedly isolated with them. Simple metallic roller bearings also exist. The source notes base isolation becomes less effective for very tall buildings, so it is more common in low- and mid-rise structures and bridges.
Washing machines, ceiling fans, vacuum cleaners, and power tools all hide bearings inside. Two smaller objects are more surprising.
Most mechanical watches still rely on jewel bearings, plain bearings made from synthetic ruby, at their pivot points. Some designers add miniature ball bearings where a part must turn with very little resistance.
The Japanese brand ŌTSUKA LŌTEC uses the world’s smallest commercial ball bearing in its No.5 KAI watch, according to MinebeaMitsumi. The movement lists 25 jewels plus 2 ball bearings, which shows how the two technologies work side by side.
The tip of a ballpoint pen holds a tiny ball seated in a socket. As you write, the ball rolls and carries ink from the cartridge to the paper. It is a single rolling ball rather than a full bearing assembly but relies on the same idea: let something roll instead of drag.
Every wheel on a car turns on a wheel bearing. Rock the wheel at the 12 and 6 o’clock positions. On vehicles with sealed bearing cartridges or hub assemblies, you should feel no play, says Tomorrow’s Technician.
The classic failure symptom is a cyclic chirp, squeal, or growl that changes with vehicle speed. Our bearing inspection checklist covers all checks for cars and industrial equipment.
Factories worldwide ran a record 5 million industrial robots in 2025, according to the International Federation of Robotics. Every joint turns on bearings, and some are ultra-thin ball bearings that flex into an ellipse as they spin, according to JTEKT’s engineering journal. Our guide to bearings in robotics explains how they work.
The record holders show how wide bearing manufacturing has become. One bearing is smaller than a grain of rice. The other is wider than two 40-foot city buses parked end to end.
| Smallest | Largest | |
| Maker | MinebeaMitsumi (Japan) | Huisman (Netherlands), built at its facility in China |
| Record | Smallest commercially available steel ball bearing, certified by Guinness World Records in 2015 | Described by Huisman as the world’s largest slew bearings, delivered in 2018 |
| Size | 1.5 mm outside diameter, 0.5 mm bore, 0.65 mm wide | 30 meters (about 98 feet) in diameter, segmented |
| Rolling elements | Six steel balls, each 0.25 mm in diameter | Rollers that can be inspected without taking the bearing apart |
| Use | Medical devices, micro-motors, micro-machines, and at least one mechanical watch | Slewing system for two 10,000-tonne tub cranes on Heerema’s crane vessel Sleipnir |
Sources: Guinness World Records, MinebeaMitsumi, KHL International Cranes, and SWZ Maritime. Before the Sleipnir project, Huisman’s largest bearing measured 14 meters.
Most industrial work happens between those extremes, and that is where Central Surplus can help. Whether you need a miniature ball bearing or a large-bore roller bearing, our team can help source the size you need. Enter the bore, outside diameter, and width in the Bearing Finder or send us the measurements and we will track it down.
| Application | What it demands | Source |
| Wind turbines | Heavy, changing loads over a design life of at least 20 years | STLE |
| Space station water system | Corrosion resistance and shock tolerance at low speed | NASA |
| Satellite reaction wheels | Long, lubricated life where repair is impossible | NASA |
| Dental handpieces | 200,000 to 400,000 rpm, heat, and autoclave sterilization | USPTO patent record |
| Earthquake isolation | Large movement under heavy building loads | Society of Engineers |
| Car wheel hubs | Sealed construction and no play | Tomorrow’s Technician |
| Robot joints | Positioning accuracy and stiffness under tilting loads | JTEKT |
Match the bearing to four factors: load direction, speed, misalignment, and environment.
Then confirm size. If the old part’s markings are unreadable, measure the bearing and run the numbers through the Bearing Finder.
Common industrial uses include electric motors, pumps, gearboxes, conveyors, fans, and vehicle wheel ends. The application sets the bearing type. Heavy radial loads call for roller bearings, while lighter, faster loads suit ball bearings. Mounted bearings like pillow block bearings simplify installation on conveyors and fans.
The smallest commercially available steel ball bearing is made by MinebeaMitsumi. Guinness World Records certified it in 2015, with an outside diameter of about 1.5 mm.
Huisman built two 30-meter segmented roller slew bearings for the 10,000-tonne cranes on Heerema’s Sleipnir, which Huisman describes as the world’s largest slew bearings.
Only when load, speed, and environment match. Two bearings can share the same outside dimensions and still behave differently. That is why the Central Surplus Bearing Finder filters by bearing type as well as size.
Ball bearings suit lighter loads at higher speeds, like dental turbines and skateboard wheels. Roller bearings suit heavier loads, like conveyors and heavy industrial gearboxes.
Whatever the application, the part has to match. Search the Central Surplus Bearing Finder by part number or measurements, or contact our team. We locate, cross-reference, and source bearings, including hard-to-find ones.
Our team can locate, cross-reference, and source all parts.
Our team can locate, cross-reference, and source all parts.
