HP PARTHAN EP GEAR OIL

150 / 220 / 320 / 460

PREMIUM INDUSTRIAL GEAR OILS

Every maintenance engineer who has worked with industrial gearboxes in India has faced the same decision at some point: which gear oil do you use?

The gearbox in your cement mill, rolling mill, sugar factory, or paper plant is one of the most critical and expensive pieces of equipment in your operation. A gearbox failure is never just a maintenance problem. It is a production stoppage, a safety incident waiting to happen, and a six-figure repair bill that nobody wants to explain to management.

The right gear oil is the single most important factor in preventing that failure. And in India, one name consistently comes up at the top of gear oil recommendations for heavy industrial applications: HP Parthan EP.

Manufactured by HP Lubricants (HPCL), the Parthan EP series is a range of premium quality industrial gear box oils that meet some of the most stringent international and Indian standards in the industry. The grades that appear most commonly in industrial procurement lists are EP 150, EP 220, EP 320, and EP 460 — each designed for a specific viscosity requirement and operating condition.

In this guide, we walk you through everything: what makes Parthan EP special, the difference between the four main grades, which industries use which grade and why, and how to make sure you are getting the genuine product. If you are a plant manager, maintenance engineer, or procurement head at an industrial facility in Punjab, Haryana, or Himachal Pradesh, this guide is written specifically for you.

What Is HP Parthan EP? The Foundation Explained

HP Parthan EP is a range of extreme pressure (EP) industrial gear box oils manufactured by Hindustan Petroleum Corporation Limited under the HP Lubricants brand. The EP in the name stands for Extreme Pressure — and that is exactly the performance promise these oils deliver.

At the heart of the Parthan EP formulation is a combination of three things:

• selected for their natural oxidation stability and viscosity retention properties: High quality mineral base stocks
• sulfur-phosphorus compounds that activate under high contact pressures to form a protective tribological film on gear tooth surfaces, preventing metal-to-metal contact under shock and heavy loads: Extreme pressure additives
• including antifoam agents to prevent air entrainment, antirust agents to protect internal surfaces during storage and operation, and antioxidation agents to extend oil life: Performance additive package

The result is an oil that does not just lubricate — it actively protects. When two gear teeth come together under heavy load, the EP additives react with the metal surfaces to form a sacrificial protective layer. This layer takes the brunt of the contact stress, preventing the scoring, scuffing, and micro-pitting that destroy gear surfaces over time.

This is not theoretical. HP Parthan EP grades are used daily in some of the most demanding gear applications in Indian industry — from the gearboxes of rolling mills in steel plants to the kiln drives of cement factories. The product has a proven track record backed by decades of field performance and multiple international approvals.