Durolub DL – technical details

Variants / Base oil / Designations (Suffix)

Durolub DL base oils are synthetic hydrocarbon oils for universal use, suitable also for the food and beverage and pharmaceutical industry. They meet the CLP-requirements of DIN51517 and are approved NSF/H1 lubricants for which an incidental contact with food cannot be avoided.

The high viscosity VI of the base oil allow to operate Durolub DL lubricated bearings within a broad temperature range. The base oil will not lose its viscosity at higher temperature and reverse, will not thicken too much at low temperatures.

Special properties:

  • Ideal wear protection
  • High oxidation and ageing resistance
  • Very good corrosion protection
  • Expanded temperature range compared to mineral oils
  • Neutral towards elastomers and plastic

Different types available

  • Suffix DL – Standard for ball bearings
    • Kinematic viscosity at 40°C – 68mm²/s (ISO 3104)
    • Kinematic viscosity at 100°C – 11mm²/s (ISO 3104)
    • Viscosity Index VI 153 (ISO 2909)
    • Operating temperature range: -40°C to + 100°C, recommended max. T = 85°C, limiting factor is the compound / oil max = 120°C
  • Suffix DL150 – Standard for roller bearings
    • Kinematic viscosity at 40°C – 140mm²/s (ISO 3104)
    • Kinematic viscosity at 100°C – 19,5mm²/s (ISO 3104)
    • Viscosity Index VI 160 (ISO 2909)
    • Operating temperature range: -35°C to + 100°C, recommended max. T = 85°C, limiting factor is the compound / oil max = 140°C
  • Suffix DL32 – Low temperature execution
    • Kinematic viscosity at 40°C – 32mm²/s (ISO 3104)
      Kinematic viscosity at 100°C – 5,9mm²/s (ISO 3104)
      Viscosity Index VI 130 (ISO 2909)
      Operating temperature range: -50°C to + 100°C, recommended max. T = 85°C, limiting factor is the compound / oil max = 140°C
  • Suffix DLSxx – special executions with other base oils, for application the DL standard is not sufficient
  • Suffix AM – antimicrobial additives
    • the suffix will be placed behind the base suffix, e.g DL150.AM
    • more details about the AM additive you can find here

Speed limits – guiding values

After filling Durolub DL and after the thermal treatment the polymer hardens and rotates together with the cage. This reduces the speed limits of the bearings.

Underneath speed limits are guiding values at a surrounding temperature of 20°C, the bearing will warm up approximately 60°C at the maximum speed and will operate below the recommended max. operating temperature of 85°C.

We experience that the real-life values are often higher, but needs to be tested and verified case by case. The speed limit variation depends on brand of bearing and execution, especially the cage has big influence. Pressed steel cages usually reach higher speed limits than Polyamide (PA) and brass / massive cages.

ndm = speed index [min-1 mm]

n = speed [min-1]

ng = speed limit (guiding value) [min-1]

dm = medium diameter [mm] / D = outer diameter of bearing [mm] / d = bore of bearing [mm]

dm = (d + D) x 0,5

ndm = n x dm

ng = ndm / dm (at 20°C surrounding temperature)

DGBB – deep groove ball bearings / ACBB – angular contact ball bearings / SABB – self aligning ball bearings / CRB – cylindrical roller bearings / TRB – tapered roller bearings / SRB – spherical roller bearings

Speed limit factor at higher surrounding temperatures than 20°C (guiding values)

If Durolub DL filled bearings are used at environmental temperatures above 20°C the speed limits ng will be reduced by factor fT

ng red = ng x fT

Low speed applications / oscillating applications

The general rules for bearing lubrication are valid for Durolub DL as well. For low speeds or oscillating movement anti-wear (AW) or extra pressure (EP) additives may be necessary to reduce wear.

Please contact the Durolub team if you need assistance.

Load carrying capacity / Measurements / Tolerances / Clearance

All these values remain unchanged. Please use the catalogue of the manufacturer chosen.

Bearing friction

By filling Durolub DL the friction torque of the bearings increase slightly at a constant value, the friction behaviour itself is the same as for the bearing type and brand chosen.

Operating temperatures

Maximum temperature

The Durolub DL compound should be operated at less than 85°C operating temperature, peaks up to 100°C can be accepted for a short time.

The Durolub DL base oils are made of synthetic hydrocarbons. In comparison with mineral oil products, this oils allow a much longer operating time, especially at higher temperatures.

Low temperature applications

Durolub DL32 can be used at starting temperatures as low as minus 50°C. At operating temperatures around or less zero degrees the DL32 offers a suitable viscosity for smooth operation at low friction.

At temperatures around and under zero degrees oils are quickly thickening. With the high oil viscosity the friction torque (torque independent from the load) is significantly increasing through the viscosity of the lubricant. This results in mixed friction at start of operation and high energy cost at low temperature operations.

standard grease (mineral oil – lithium soap) as used in DGBB of a premium bearing manufacturer / compound and compound H1 are competitors product

Abutment construction

The abutment construction for Durolub DL filled bearings does not need to changed. Please obey the recommendations of the bearing manufacturers catalogues.


If bearings need to heated up for assembly then induction heaters are highly recommended. Do not use heating plates or hot oil. Do not exceed 120°c for assembly.

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