Molybdenum disulfide (MoS₂) coating
Resin-bonded molybdenum disulfide solid lubricant, applied by spray on fasteners and threaded components to control tightening friction.
MoS₂ is lamellar: the layers slide over each other under load, and that is what gives low friction exactly where grease does not stay — threaded joints, high pressure and low speed. It does not run, does not attract particulates and does not depend on reapplication, which is what decides in equipment with no access for corrective maintenance. What it is not: a corrosion barrier. In a wet, saline environment molybdenum disulfide oxidizes, and a solid lubricant alone does not replace a protective layer. That is why, in marine applications, it goes on as a top layer over a metallic base — zinc-nickel or NanoGalv® — in a combined system: the metallic layer protects by sacrifice, the solid lubricant controls tightening friction. We apply it today, under the customer’s specification: state the standard and the friction requirement of your end customer and our sales team confirms what we meet in that case. On a new project, testing to your customer’s standard is part of the development, with our sales team alongside at every step.
Technical data
- Chemistry
- Resin + molybdenum disulfide (MoS₂)
- Color
- Gray
- Application
- Spray, with oven cure
- Function
- Tightening-friction control and anti-seizing
- Preparation
- Blasting and manganese phosphate
- Products applied
- PPG (Whitford) · Molykote · Everlube
- Thickness
- Defined with our sales team, according to the part and the customer’s standard
- In a combined system
- Top layer over zinc-nickel or NanoGalv®
- Application
- Under the customer’s friction specification
What specifiers usually ask.
Does molybdenum disulfide protect against corrosion?
No. It is a solid lubricant, not a corrosion barrier: in a wet and saline environment MoS₂ oxidizes and loses performance. In marine applications it goes on as a top layer over a metallic base — zinc-nickel or NanoGalv® — in a combined system. The metallic layer gives the salt-spray hours; the solid lubricant gives predictable friction at tightening and disassembly.
What is the difference between molybdenum disulfide and PTFE?
They are solid lubricants with different strengths. MoS₂ works better under high load and low speed, which is the case of the threaded joint. PTFE gives low friction with good chemical inertness and a wide thermal range. There is no need to choose: Xylan® 1425, which we apply in production, combines both in the same coating.
Does Sapucaia apply molybdenum disulfide?
Yes. The application capability is installed and the process runs: blasting, manganese phosphate and the pure MoS₂ solid lubricant, grey, with the layer defined by our sales team according to the part and your project’s standard.
Which standards govern the solid-lubricant coating?
The reference standards for the product are MIL-PRF-46010, SAE AS5272 and AMS2526, with wear life assessed by ASTM D2625 and fastener friction measured by ISO 16047. They are the market reference for solid lubricant. State the standard your end customer requires and our sales team replies with what we meet today.
Why apply with you, if the product is off the shelf?
Because Xylan® is not an off-the-shelf product. The line only reaches those the manufacturer qualifies: without that qualification you cannot buy the product or supply the part coated with it. Sapucaia is a PPG (Whitford) approved applicator, and the audit behind that is the manufacturer’s, not ours — it is the same requirement that Petrobras specification I-ET-3010.00-1200-251-P4X-001 makes, in §5.3.4.4, for fluoropolymer on FPSO bolts. Molykote and Everlube have no such requirement: they are freely purchasable. Add the metallic base under the same roof, zinc-nickel and NanoGalv®, and the same work order covers both layers of the combined system, with a single trace and a single responsibility.
Is it suitable for controlling tightening torque?
That is exactly what the oil and gas market specifies it for. Unstable thread friction makes the same torque generate different clamp loads, and what fails afterwards is the joint, not the bolt. The solid lubricant makes friction repeatable. To declare the friction value of your part, a torque-tension test to ISO 16047 is needed, in an external laboratory — and the test on pure MoS₂ is already under way. Our sales team gives you the status and develops the test with you according to the part and the project standard.