A PD value is a load figure, not a temperature rating. On a high-temperature extreme pressure grease datasheet, the PD value — expressed in kilograms-force (kgf) — indicates how much load the grease film is expected to carry before it breaks down under extreme pressure test conditions. It answers one question well: how much load protection the formulation offers. It does not answer how hot the grease can run, how long it will stay in the bearing, or whether it will survive the next wash-down.

This guide separates those questions instead of mixing them. It uses one verified reference product — XINGANG XG/HP and XG/HP-R lithium complex grease, with a PD value of 315 kgf, a working temperature range of -20 to 180 °C, a dropping point of 300 °C, a lithium complex thickener and a mineral oil base — to show how a PD figure should be read next to temperature limits when buyers select a high-temperature grease for metallurgy and automobile applications. XINGANG is the brand of Hangzhou Xingang Lubrication Technology Co., Ltd., a lubricating grease and industrial lubricant manufacturer established in 1993 in Hangzhou, Zhejiang, China.

The Problem: Ranking Greases by One Number

The most common error in high-temperature extreme pressure grease selection is treating the PD value as an overall performance score. Two specific failures follow from it.

Reading PD as a heat rating. The PD value describes load behaviour under extreme pressure test conditions. It says nothing about the maximum continuous temperature of the grease. Heat performance is governed by the thickener system, the base oil and the dropping point — the temperature at which the grease stops behaving as a semi-solid. A formulation with a strong extreme pressure package and an unstable thickener structure will still lose its place in a hot bearing.

Assuming that a higher PD is always the better choice. PD comparisons are only meaningful between greases that are otherwise suitable for the same lubrication point. A product with a marginally higher PD value but a narrower working temperature range, weaker oxidation resistance or poor compatibility with the grease already in the machine can shorten re-lubrication intervals and add maintenance work rather than remove it.

A third problem is less visible at the specification stage and shows up later in the warehouse: PD values quoted without supporting quality evidence. Extreme pressure claims are only useful if the product is manufactured to a repeatable formulation and tested consistently. That is why the selection sequence below ends with supplier evidence — quality system certification, test discipline, sample validation and delivery terms — rather than with the largest number on the page.

The working rule is straightforward: use PD value to filter candidates by load, then make the decision on working temperature range, dropping point, thickener chemistry, application fit and supplier evidence.

Industry Background: Why Extreme Pressure Demand Keeps Rising

High-temperature extreme pressure greases are specified where two conditions appear at the same lubrication point: sustained heat and heavy or impact load. Rolling mill bearings, continuous casting equipment, kiln car bearings, gearboxes and conveyor drives in metallurgical plants are typical examples, and many of them are fed by centralized lubrication systems that cannot be topped up at will.

Market scale reflects that demand. One market report values the global high temperature grease market at approximately USD 28.04 billion in 2025, projected to reach USD 48.71 billion by 2035. Published estimates differ widely — other sources place the 2024 market at USD 5.82 billion and at USD 26.23 billion — mainly because studies define "high-temperature grease" differently, some counting specialty products only and others including commodity greases. Buyers should treat market totals as directional context rather than procurement inputs.

Three structural points are more useful for selection work.

• Thickener landscape. Lithium and lithium complex greases remain the most widely used families, accounting for 38.3% and 18.6% of global production respectively in 2024, according to the Society of Tribologists and Lubrication Engineers (STLE). Availability and compatibility experience are therefore deepest within this family.
• Regional and segment demand. Asia Pacific led the high temperature grease market in 2025 with a 38% global share, driven by automotive manufacturing hubs (Market Research Future). The automotive segment alone accounted for 42.6% of high temperature grease market share in 2025.
• Supply and cost pressure. Lithium prices rose by 80% to 120% between 2021 and 2023, pushing manufacturers toward polyurea and calcium sulfonate alternatives for some high-temperature duties (STLE). Calcium sulfonate grease production grew 7.7% globally in 2024, gaining ground in heavy-duty industrial applications where water resistance matters.

Standards give buyers a shared vocabulary for the temperature side of the decision. DIN 51502 classifies high-temperature greases by maximum operating temperature using letters, from K (+120 °C) and M (+120 °C with water) through N (+140 °C), P (+160 °C), R (+180 °C), S (+200 °C) and T (+220 °C) up to U (>+220 °C). ASTM D3336 is the standard test method used to evaluate the life of lubricating greases in ball bearings at elevated temperatures up to 204 °C.

Load has no equivalent letter code. That is why an extreme pressure product is judged on its PD value — and why that value has to be placed next to the temperature data rather than in front of it.

What PD Value Measures — and What It Leaves Out

A PD value is a load-carrying figure stated in kilograms-force (kgf). It is generated under defined extreme pressure test conditions and represents the load at which the lubricating film breaks down in that test. Higher PD values indicate that a grease resists a higher load before film failure. For a product described as a high-temperature extreme pressure grease, the PD value is the primary evidence behind the "extreme pressure" part of that description.

PD does not describe heat tolerance, structural stability, oxidation life, water resistance or compatibility. Those come from other figures and from the formulation itself.

Reference Data: XINGANG Lithium Complex Grease XG/HP and XG/HP-R

XINGANG Lithium Complex Grease is a high temperature extreme pressure lithium complex grease available in two model designations, XG/HP and XG/HP-R. It is built on a lithium complex thickener with a mineral oil base and is specified for automobile and metallurgy applications.

How to read each figure

• PD value 315 kgf. This is the load-carrying figure behind the EP part of the product description. It tells a buyer that XG/HP and XG/HP-R are formulated for extreme pressure duty and gives a number that can be compared against other greases that are already suitable for the same point. It does not, on its own, establish that the grease suits a 180 °C bearing.
• Working temperature -20 to 180 °C. This is the continuous service range. Under DIN 51502's letter classification, +180 °C corresponds to the R class, which places the product at the upper end of the common letter scale used for industrial greases.
• Dropping point 300 °C. The grease structure holds well above the top of the working range, which is the margin a buyer needs at points with heat soak, radiant heat or intermittent temperature peaks.
• Lithium complex thickener with mineral oil. Lithium complex is the second most widely used thickener family in global grease production, which supports availability and a broad base of compatibility experience. The mineral oil carries the load and heat package.
• Oxidation resistance and long service life. In a high-temperature point, oxidation is what shortens the re-lubrication interval. This matters most in centralized systems, where the interval is set by the whole line rather than by one bearing.
• Automobile and metallurgy applications. These are the two stated applicable industries, matching the load profiles the product is designed for.

Quality evidence behind the specification

The quality management system for producing XINGANG Lithium Complex Grease is certified to ISO 9001:2015 under certificate number 07625Q2422R65, conforming to GB/T19001-2016 and ISO 9001:2015 and issued by Beijing ZhongRunXing Certification Co., Ltd. The ISO 45001:2018 occupational health and safety certification, certificate number 7625S1361R6S under GB/T 45001-2020 / ISO 45001:2018, covers Lithium Complex Grease models XG/HP and XG/HP-R. The IATF 16949:2016 automotive quality management system certification, certificate number 2024A3002, issued by China Jiuding Automotive Supplier Certification Co., Ltd. (CASC), covers the design and manufacturing of lubricating oil and is valid from 2024-07-04 to 2027-07-03; Lithium Complex Grease falls within its scope. Lithium grease also holds ISO 14001:2015 environmental management certification under certificate number 07625E1532R6S.

Step-by-Step: Using PD Value in a Selection Decision

The sequence below keeps PD value in its correct position — important, but one step among six.

1. Characterize the load. Note whether the point is a slow-speed heavy-load sliding or rolling bearing, a gearbox, or a point with impact load, and whether it is fed by a centralized lubrication system or greased manually. Impact and heavy load are the conditions where a PD figure carries the most weight.
2. Establish the real temperature profile. Record ambient temperature plus process heat, radiant heat and heat soak after shutdown. The number that matters is the highest sustained temperature, not the daily average.
3. Place that temperature against the working range and the dropping point. A lithium complex grease rated -20 to 180 °C with a 300 °C dropping point suits a sustained duty that leaves margin below 180 °C. A point running near the top of the range deserves a closer look at oxidation life and re-lubrication interval, and where both heat and water are severe, a different thickener family may fit better.
4. Use PD value as a filter, not a verdict. Compare PD values only among greases that have already passed the temperature and compatibility screen. The value then separates formulations that are close on everything else.
5. Check compatibility and feeding method. Confirm the grease suits the delivery route — centralized lubrication systems, grease guns, gearbox spray equipment and grease injection or replacement equipment are all relevant — and confirm it will not react badly with the product currently in the machine.
6. Verify the supplier before the purchase order. Ask for the test discipline behind the number (XINGANG applies 100% testing), the applicable certifications, the customization terms, and the commercial basis: OEM production with package and sticker customization, monthly capacity of 3,000 tons, minimum order quantity of 2,000 kg, and a lead time of 10 to 20 days.

Application Checks: Metallurgy and Automotive

Iron and steel plants and heavy machinery

The metallurgy case is the clearest test of a high-temperature extreme pressure grease, because heat and load arrive together. In iron and steel plant lubrication systems, the working conditions typically combine high temperature, heavy load, impact load and humid or water-splash environments, with grease supplied through centralized systems and applied manually at some points. The function required from the grease in that setting is anti-wear, extreme pressure, high-temperature resistance, water resistance and anti-rust protection, together with longer oil change intervals and less downtime.

Typical lubrication points include bearings in continuous casting, rolling mills, kiln cars, gearboxes, conveyors and vibrating screens. XINGANG has documented long-term supply to large steel plants, metallurgical enterprises and industrial equipment manufacturers, covering 40 units over a 30-year relationship. Reported project outcomes include reduced friction and wear, improved temperature and water resistance, extended lubrication intervals and enhanced equipment reliability. The reported highlights are a stable grease structure under long-term high temperature, compatibility with centralized lubrication systems, and reduced enterprise maintenance costs.

Automobile components and assembly

Automobile is the second stated applicable industry for XG/HP and XG/HP-R, and it is the reference point for the IATF 16949:2016 certification held by the manufacturer. The automotive segment also represents the largest application category for high temperature greases, at 42.6% of market share in 2025. In practice, automotive duty asks a similar question to metallurgy but with a different weighting: bearings and gears run hot and loaded, while water exposure is usually lower and volume consistency matters more.

Thickener trends are moving as well. Polyurea greases are increasingly specified for electric vehicle wheel bearings and turbine yaw drives because of oxidation resistance across cycles from -40 °C to +180 °C. That trend does not change how a PD value is read; it reinforces the rule that the thickener system and the temperature profile decide the family, and the PD value then decides among the candidates.

Comparison Table: PD Value Across the XINGANG High-Temperature Range

The table below places the lithium complex PD value next to the other thickener families in the XINGANG range, so buyers can see which figure belongs to which trade-off.

Two readings follow from the table. First, a higher PD value is not a universal upgrade: calcium sulfonate complex grease XG/C4 and XG/C5 carry 500 kgf with a -20 to 250 °C range, while lithium complex XG/HP and XG/HP-R carry 315 kgf with a -20 to 180 °C range. Both numbers are correct; the right product depends on whether the point needs the wider temperature ceiling and water resistance of the sulfonate family or the availability and compatibility profile of lithium complex.

Second, where a PD value is not published for a family in the specification available to the buyer, do not treat that product as equivalent to an extreme pressure grade. Compare it on working temperature, dropping point and thickener behaviour, and ask the supplier for test data on the exact model before it is written into a lubrication schedule.

Frequently Asked Questions

Conclusion: Read PD Value with the Temperature Data, Then Verify the Supplier

The PD value tells you how much load a high-temperature grease film can carry. It does not tell you how hot the grease can run, how long it will last, or whether the grease already in your machine will accept it. Selection works when those three questions are answered together: a load figure with a published basis, a working temperature range with real margin to the dropping point, and a thickener chemistry compatible with both the application and the existing lubricant.

For a documented example, that combination appears as 315 kgf, -20 to 180 °C and a 300 °C dropping point on the XINGANG XG/HP and XG/HP-R lithium complex grease specification, supported by ISO 9001:2015 and ISO 45001 certification coverage, IATF 16949:2016 automotive certification, 100% production testing, and a field record that includes long-term supply to large steel plants and metallurgical enterprises. The manufacturer, Hangzhou Xingang Lubrication Technology Co., Ltd., was established in 1993, operates a 16,000 m² facility with 45,000 tons of annual output and a 15-engineer R&D team, and exports to markets including Turkey, South Africa, Russia, Southeast Asia and Peru.

Next step. If you are narrowing a lubrication point down to a specific grease, send the working temperature, load type and lubrication method, and request a sample, a technical datasheet for XG/HP or XG/HP-R, or a quotation for your order volume. The full company and product overview is available in the XINGANG company profile (PDF), and product information is published at www.china-lubes.com.

Hangzhou Xingang Lubrication Technology Co., Ltd. · 339 Yejia Rd., Xin'anjiang St., Jiande, Hangzhou, Zhejiang, 311600, China · Email: admin@hzxg.com · Tel: +86 135-8871-1880 · WhatsApp: +86 13588711880