What Is JetLube MP-50 Moly Paste and How Does It Work?

JetLube MP-50 Moly Paste is a non-melting, thick-consistency lubricating compound formulated with a high percentage of molybdenum disulfide (MoS2) suspended in an organo clay thickener with a petroleum fluid base. Its blue-to-black paste texture allows application by brush or spatula directly onto metal surfaces, including hot ones, without running off or dripping. The compound can also be applied at temperatures as low as 0°F (-18°C), making it viable across extreme seasonal and operational conditions.

MoS2 is the functional core of MP-50. It “plates” metal surfaces by filling microscopic voids, reducing high points, and increasing the effective load-carrying area. This mechanism directly lowers friction, suppresses galling, prevents seizure and stick-slip, and reduces bearing temperatures under boundary lubrication conditions. The friction coefficient of MP-50 measures 0.06, making it one of the lowest-friction options for extreme-pressure applications.

What Is the Temperature Range of JetLube MP-50 Moly Paste?

MP-50 carries a service rating of -300°F (-185°C) to 750°F (400°C) for anti-seize applications. In mechanical components not exposed to air, good lubrication results can be anticipated up to 2000°F (1090°C). MoS2 itself is nearly inert in operating conditions up to 600°F (315°C). If the grease vehicle is expelled under extreme load, the moly disulfide remains on working surfaces to maintain protection — a critical advantage over petroleum-only or wax-based compounds that leave surfaces bare when displaced.

The non-melting formulation distinguishes MP-50 from asphaltic or wax-based lubricants, which soften and migrate at elevated temperatures. MP-50’s ASTM D-566 dropping point is listed as none, confirming no melt transition across its rated range. The flash point (ASTM D-92) exceeds 430°F (221°C).

How Does JetLube MP-50 Perform Under Extreme Pressure and Load?

MP-50 achieves a 4-Ball Weld Point of 250 kgf minimum (ASTM D-2596), confirming high extreme-pressure performance. The product is rated for high chrome alloys at 60,000 PSI contact stress and carries an NLGI Grade of 2½, with a penetration of 250–270 mm×10⁻¹ at 77°F (ASTM D-217). The nut factor (K) is 0.11, derived from the short-form torque equation T = K × D × F, where T is torque, D is bolt diameter, and F is bolt tension generated during tightening. This controlled nut factor enables predictable bolt load in structural and flange applications.

Oil separation weight-percent loss at 212°F is less than 1.0%, indicating the compound retains its consistency under sustained elevated temperatures. Copper strip corrosion rating is 1A (ASTM D-4048), confirming compatibility with copper alloy components.

What Applications Is JetLube MP-50 Specified For?

MP-50 is the only product specified in NAVSEA TMS S 9958-AA-MMA-100 Volume 10 Book 1 for Marotta control valves — a demanding military specification that confirms its reliability in high-pressure, multiple-actuation service. Many OEM valve manufacturers have selected MP-50 as their premier valve stem lubricant because it shows almost no loss in performance across repeated actuations, where competing products exhibit progressively increasing torque.

Additional documented applications include:

Subsea riser, blowout preventer (BOP), and flange equipment
Structural bolts, onshore and offshore
Cam lubrication
Assembly and disassembly of press and shrink-fit pins, shafts, splines, bushings, sprockets, gears, and bearings
Highly loaded gears, open spur gears, and marine transmission gears prone to scoring

How Does JetLube MP-50 Resist Corrosion and Environmental Exposure?

MP-50 is water resistant and formulated to withstand extreme weather elements. It helps prevent corrosion on parts exposed to water, steam, most acids, and alkalis. The specific gravity of 1.40 and density of 11.7 lbs/gal reflect the high MoS2 loading in the compound.

The compound is lead-free, aligning with environmental and regulatory requirements across industrial and military supply chains. Its tenacious adhesion to metal surfaces ensures the protective film remains intact under vibration, thermal cycling, and repeated mechanical loading — conditions common in offshore, marine, and heavy industrial environments.

When Should You Use JetLube MP-50 vs. Standard Lubricants?

For applications beyond its rated temperature range, a different product family should be evaluated.

The low pour point oil base provides reduced torque compared to asphaltic or wax-based lubricants in extreme cold, while the non-melting, thick consistency allows MP-50 to remain in position under extreme loads and elevated temperatures. Highly loaded gears and components prone to scoring with normal lubricants should be pre-dressed with MP-50 before initial service entry.

JetLube manufactures MP-50 in the USA in an ISO 9001:2015 and ISO 14001:2015 certified facility.

Summary

JetLube MP-50 Moly Paste operates from -300°F to 750°F for anti-seize use, and up to 2000°F in non-air-exposed mechanical components.
The friction coefficient is 0.06 and the 4-Ball Weld Point minimum is 250 kgf (ASTM D-2596), confirming extreme-pressure capability.
MP-50 is the only lubricant specified in NAVSEA TMS S 9958-AA-MMA-100 Volume 10 Book 1 for Marotta control valves.
The lead-free, water-resistant compound resists corrosion from water, steam, most acids, and alkalis, with a copper strip corrosion rating of 1A (ASTM D-4048).
Manufactured in the USA under ISO 9001:2015 and ISO 14001:2015 certification; suitable for subsea, offshore, valve, gear, and structural bolt applications.

Step-by-step

Apply MP-50 by brush or spatula directly to clean metal surfaces, including hot surfaces, ensuring full coverage of contact areas.
Pre-dress highly loaded gears, open spur gears, or components prone to scoring with MP-50 before placing them into initial service.
For press and shrink-fit assemblies, coat pins, shafts, splines, or bushings with MP-50 prior to assembly to facilitate subsequent disassembly.
Apply to valve stems, BOP components, and structural bolt threads, using the nut factor K=0.11 to calculate target installation torque via T = K × D × F.
Store and apply at temperatures as low as 0°F (-18°C); no pre-heating is required due to the low pour point oil base.

Products discussed in this episode

Jet-Lube MP-50

Browse all JetLube products on PE Energy Industrial Supply.

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