Ashless (Zinc Free) Hydraulic Oil

Ashless hydraulic oil, also known as zinc-free hydraulic oil, is a high-performance hydraulic fluid formulated without zinc or other metallic antiwear additives. Instead, it uses non-metallic (ashless) additive technology to provide superior wear protection, oxidation resistance, and system cleanliness—making it ideal for applications where zinc-based oils may cause harm to sensitive components, yellow metals (like brass or copper), or the environment. These oils meet or exceed the performance requirements of traditional antiwear hydraulic fluids, while offering better thermal stability and lower ash content, reducing deposits and varnish in high-speed, high-pressure hydraulic systems.

Ashless hydraulic oil is commonly used in environmentally sensitive areas, indoor manufacturing facilities, and systems with silver or copper-lined components. It's widely approved for use in precision industrial machinery, robotics, pharmaceutical or food-processing equipment (non-food contact), power generation systems, and hydraulic applications with tight tolerances. Zinc-free hydraulic oil is also preferred in equipment with servo valves, vane pumps, or systems running at elevated temperatures, where sludge or varnish buildup could affect performance.

Common Zinc-Free Hydraulic Oil Grades and Their Uses:

• AW 32 (Ashless) – A low-viscosity hydraulic fluid ideal for colder climates, indoor machinery, or precision systems requiring fast startup and low drag.

• AW 46 (Ashless) – A versatile, mid-viscosity option suited for most general-purpose hydraulic systems, offering a balance of flow and film strength in moderate climates.

• AW 68 (Ashless) – A higher-viscosity zinc-free fluid ideal for high-load, high-heat, or outdoor industrial equipment that requires robust film protection.

These ashless hydraulic fluids meet key industry performance standards such as ISO 11158 (HL/HM/HV), DIN 51524-2 (HLP), and OEM requirements for non-zinc hydraulic systems from brands like Denison, Parker, Bosch Rexroth, and Vickers.

Packaging Options Available:

• 5-gallon pails – For shop and mobile service work

• 55-gallon drums – Common for industrial and plant operations

• 275-gallon totes – Bulk supply for high-volume users and fleet maintenance

Zinc-free hydraulic oils offer cleaner operation, longer fluid life, and superior performance in environmentally sensitive or high-precision systems. Whether you need AW 32 ashless oil for high-speed machinery or AW 68 for heavy-duty hydraulic equipment, we carry premium ashless fluids that protect your systems without compromise.