Walk into any maintenance workshop across India and ask the technician which hydraulic oil they use — and most will say ‘AW 46’ without hesitation. But is that always the right choice? The difference between AW 46 and AW 68 can mean the difference between smooth machine operation and sluggish, overheated hydraulics. This guide explains exactly when to use each grade.
What Does AW Mean in Hydraulic Oil?
AW stands for Anti-Wear. It indicates the oil contains additives that protect hydraulic pump components — particularly vanes, pistons, and gears — from metal-to-metal contact under pressure. Without AW additives, hydraulic systems that operate at high pressures would suffer rapid wear on pump internals. The number following AW (32, 46, 68, 100) refers to the ISO VG (Viscosity Grade) — a measure of the oil’s thickness at 40°C.
AW 46: The General-Purpose Workhorse
AW 46 (also called VG 46) has a kinematic viscosity of approximately 46 centistokes at 40°C. It is the most widely used hydraulic oil grade globally and in India. It is suitable for: industrial hydraulic systems operating in moderate to warm ambient temperatures, mobile equipment like excavators, loaders, and forklifts in standard duty, injection moulding machines, presses, and general factory hydraulics, and systems where the manufacturer specifies ISO VG 46 or AW 46.
AW 68: For High-Load and High-Temperature Applications
AW 68 is thicker at operating temperature — approximately 68 cSt at 40°C. It is preferred when: ambient or operating temperatures are consistently high (above 40°C ambient, common in Indian summer conditions in unventilated factory floors), the hydraulic system runs at high operating pressures (above 250 bar), heavy-duty equipment like large presses, mining hydraulics, or steel plant machinery is involved, or the OEM specifies VG 68 in tropical climate versions of their equipment manuals.
The Temperature Rule of Thumb
A simple guide: if your machine operates in an environment where ambient temperature stays below 35°C, AW 46 is usually appropriate. If ambient temperatures regularly exceed 40°C — as they do during Indian summers in factory environments without proper cooling — AW 68 provides better film strength and reduces the risk of oil thinning to the point of inadequate lubrication. During winter months in North India, AW 32 may be more appropriate for outdoor equipment.
Industries Using AW 46 and AW 68 in India
Ceramic tile industry: Gujarat’s ceramic belt uses large tonnage hydraulic presses — typically on AW 68 due to high operating pressures and temperatures. Textile industry: ring frame machines and knitting machines use lighter hydraulics on AW 46. Steel plants: rolling mills and press equipment run on AW 68 or higher. Sugar mills: cane crushing hydraulics typically run on AW 68 during peak season when continuous duty generates heat. Paper mills: calender rolls and press sections use AW 46 typically.
Lukeron Hydraulic Oils — Available for All Industries
Lukeron Lubricants supplies hydraulic oils in VG 32, 46, 68, and 100 grades for automotive, marine, mining, textile, ceramic, steel, sugar, power, and paper industries. Our hydraulic oils are available in 20-litre, 200-litre, and bulk supply options for industrial customers across India and for export.
📞 CONTACT & CTA
Enquire about hydraulic oil supply: +91 73832 79438 | info@lukeronlubricants.com
