Product selection
Reviewed by MAXILUB · 5 min read · Updated 2026-08-28
What the viscosity grade means
AW hydraulic oils are commonly identified by an ISO viscosity grade. AW 32 is lighter than AW 46, while AW 68 is the heaviest of the three at the grade's reference temperature. The grade affects cold-start flow, operating film thickness and energy efficiency. It does not identify a universal quality level, so viscosity should be evaluated together with the product data sheet and the equipment manufacturer's specification.
Where each grade is commonly considered
AW 32 is often considered for colder starts or equipment designed for a lighter hydraulic fluid. AW 46 is widely used in moderate operating conditions and is a common starting point for many industrial systems. AW 68 may be considered where equipment, ambient temperature or operating load calls for a heavier grade. These are general patterns, not substitutions for the equipment manual.
Do not select by climate alone
Ambient temperature matters, but reservoir temperature, pump design, duty cycle, contamination control and seal compatibility also influence selection. A fleet with several equipment types may require more than one grade. Before consolidating products, confirm that every affected asset permits the proposed viscosity and performance level across the full operating range.
Information to include in a quote request
Provide the equipment make and model, the required ISO grade, annual or monthly volume, package preference and delivery ZIP code. If the manual lists an OEM specification or hydraulic-fluid standard, include that wording. MAXILUB can then match the request to available product documentation and commercial package options without guessing at the application.