Engineering Reference
Precision Ball & Roller Bearings
(Medium to Large Diameter)
Lubrication
Selecting the best lubricant for a particular application is critical to achieving the full rated life of the bearing and optimal performance of the assembly, but choosing from the hundreds available can be an overwhelming task. The charts published below list a narrow selection of lubricants we use on a regular basis. They cover a wide range of temperatures, rotational speeds, load conditions and assembly designs. Please contact NHBB HiTech's applications engineering department for help with making your final selection.
Oil
Petroleum and synthetic oil lubricants are used in conjunction with a circulating system that maintains the proper oil level and removes heat from the bearing assembly. While oil is suitable for a wide range of operating speeds, it is the preferred method of lubrication for high speed applications. Petroleum oils are still widely used because of their excellent performance characteristics at normal operating temperatures and medium to high speeds. Synthetic oils are used in many critical high speed and high temperature applications because they possess improved thermal properties, lower volatility and superior viscosity. Synthetic oils encompass a wide spectrum of engineered fluids including diesters, silicones and fluorinated compounds.
Grease
Grease is ideal for applications where frequent replenishment of a lubricant is undesirable or impossible. Compared to oil, grease has a limited speed capability because it does not remove heat from the bearing and increases torque. Grease consists of a base oil, thickeners and other additives. The base oil acts as the lubricating agent while thickeners keep the oil in suspension before releasing it under pressure. The additives function as antioxidants, rust inhibitors and stabilizers.
Solid Film
Solid film lubricants are used primarily in situations where oil and grease lubricants would fail, namely in harsh conditions characterized by extremely high or low temperatures, the chance for radiation exposure or the presence of a vacuum (e.g., space). Most solid film lubricants possess a finite operating life because they cannot be replenished once they wear away from the contact surfaces, which make them best suited for light load and low speed applications. Solid film lubricants encompass everything from sacrificial retainers to graphite powders, molybdenumdisulfide powders and ion sputtering. Detailed information on solid film lubricants has not been provided here, as each type must be engineered for the specific application.
Table of Oil Lubricants
| NHBB Code | Brand Name | Type | Military Specification | Operating Temp Max. | General Comments |
|---|---|---|---|---|---|
| LO1 | Windsor Lube L-245X | Diester | MIL-PRF-6085 | -65 — 300°F | General purpose instrument oil, low volatility |
| LO2 | Royco® 885 | Diester | MIL-PRF-6085 | -65 — 250°F | General purpose instrument oil, low volatility |
| LO71 | BP Turbo Oil 2389 | Diester | MIL-PRF-7808 | -65 — 300°F | General purpose aircraft lubricant |
| LY115 | Krytox 143AC | Perfluorinated polyether | -30 — 550°F | High temperature stability. Vacuum applications | |
| LY223 | Braycote® Micronic® 815Z | Perfluorinated polyether | -112 — 400°F | Wide temperature range. Vacuum applications | |
| LY378 | Castrol® 399 | Diester | MIL-PRF-7808 | -65 — 300°F | General purpose aircraft lubricant |
| LY559 | Nye® Synthetic Oil 2001 | Cyclopentane | -45 — 250°F | Special oil for outer space & high vacuum applications |
Table of Grease Lubricants
| NHBB Code | Brand Name | Type | Military Specification | Operating Temp Max. | General Comments |
|---|---|---|---|---|---|
| LG4 | Aeroshell® 22 | PAO/Microgel | MIL-PRF-81322 | -85 — 400°F | Wide temperature range, good low temp. torque. Aircraft, general purpose. NLGI 2* |
| LG20 | Beacon 325 | Diester/Lithium complex | -65 — 250°F | General purpose instrument grease. NLGI 2* | |
| LG49 | Aeroshell® 7 | Diester/Microgel | -100 — 300 °F | General purpose, low temp. torque, wide temperature range. NLGI 2* | |
| LG68 | Royco® 27 | Diester/Lithium complex | MIL-PRF-23827 | -100 — 275 °F | General purpose, low temp. torque, wide temperature range. NLGI 2* |
| LY48 | Mobilgrease® 28 | PAO/Organo-clay | MIL-PRF-81322 | -65 — 350 °F | Wide temperature range, good low temp. torque. Aircraft, general purpose. NLGI 2* |
| LY51 | Isoflex® NBU15 | Ester/Barium complex | -40 — 265 °F | High speed, spindle quality grease. NLGI 2* | |
| LY101 | Krytox® 240AC | Perfluorinated/PTFE | MIL-PRF-27617 Type III | -30 — 550 °F | High temperature stability, wide temperature range. Vacuum applications. NLGI 2* |
| LY308 | Braycote® 601 EF | Perfluorinated/PTFE | -112 — 400 °F | Wide temperature range. Vacuum applications. NLGI 2* | |
| LY548 | Rheolube® 2000 | Cyclopentane/Sodium complex | -45 — 250 °F | Special grease for outer space & high vacuum applications | |
| LY660 | Polyrex® EM | Mineral/Polyurea | -20 — 350 °F | Electric motor grease. Good high temperature grease. NLGI 2* | |
| LY669 | Rheolube® 374-C | PAO/Lithium complex | -40 — 300 °F | Channeling type grease, high speed. Good for vertical applications. NLGI 4* | |
| LY703 | Rheolube® 374-A | PAO/Lithium complex | -40 — 300 °F | General purpose grease. Good speed/temperature range. NLGI 2* | |
| LY706 | Kluberquiet® BQH 72-102 | Ester/Polyurea | -45 — 350 °F | Quiet running, wide temperature range. NLGI 2* |
*National Lubricating Grease Institute—number refers to grease thickness.
Registered Trademarks
Aeroshell® – Royal Dutch Shell Plc.
Brayco® Micronic®, Castrol® – Castrol Limited.
Isoflex®, Kluberquiet® – Klüber Lubrication, a company of the Freudenberg Group.
Krytox® – DuPont de Nemours, Inc.
Mobilgrease®, Polyrex® – Exxon Mobil Corporation.
Royco® – Anderol Company.
Nye®, Rheotemp®, Rheolube® – Nye Lubricants, Inc.
