What Is Never-Seez and How Does It Prevent Fastener Seizure?
Never-Seez is Bostik’s line of anti-seize and lubricating compounds, recognized for over 50 years as an industry standard for nut and bolt assembly and disassembly. Applied to fastener threads and mating surfaces, these compounds reduce friction, resist corrosion, and enable non-destructive disassembly even after extended exposure to heat, pressure, and environmental contamination.
The compounds protect against seizure, galling, carbon fusion, rust, galvanic action between dissimilar metals, and degradation from chemical vapors, road salt, steam, and water. They are also inert to most gases including propane, butane, natural gas, helium, freon, and nitrogen, and are impervious to strong alkaline solutions.
How Does Never-Seez Affect Torque and Clamping Force?
Never-Seez compounds reduce the torque required to achieve a target clamping force, or increase clamping force for a given applied torque, compared to unlubricated fasteners. Bostik engineers quantify this using a K-Factor baseline of 0.185 for unlubricated carbon steel fasteners. Dividing a specific Never-Seez product’s Torque Coefficient K-Factor by 0.185 yields the percentage difference in torque value for that product.
The practical result: the same clamping force can be achieved with less applied torque, or greater clamping force is generated when the specified torque is applied. The exact percentage varies by formula — each Never-Seez grade has its own K-Factor value documented in the individual product information sheets at bostik.com/us.
What Are the Nine Never-Seez Grades and Their Applications?
Never-Seez comprises nine distinct grades, each engineered for targeted conditions:
- Regular Grade: The original anti-seize compound. Contains copper, graphite, aluminum, and other ingredients. Rated for 1,600°F–1,800°F. Protects against rust, corrosion, and seizure in high heat, high pressure, and corrosive environments.
- Pure Nickel Special: High-temperature, extreme-pressure compound with flake pure nickel, graphite, and additives. Rated 2,000°F–2,400°F. Copper-free; recommended when chemical resistance is required.
- Nickel Nuclear Grade: Same formulation as Pure Nickel Special but tested and certified for nuclear power plants. Each production lot tested for sulfur, halogens, and low-melt metals; each container labeled with lot and test report number. Meets GE Nuclear Energy D50YP12 / GE D6Y6C1 specifications.
- Black Moly: High concentration of molybdenum disulfide. Withstands pressures up to 500,000 PSI. Rated –150°F–1,500°F. Copper- and graphite-free. Best for extreme-pressure, heavy-load, slow-speed applications prone to boundary lubrication failure.
- Blue Moly: Combines molybdenum disulfide and pure nickel flake in premium-grade grease. Withstands 300,000 PSI. Rated 10°F–750°F. Metal-free formulation; suitable where graphite, zinc, lead, and copper are prohibited. Contains special corrosion inhibitors for harsh environments.
- High Temperature Stainless: Stainless steel, graphite, and aluminum-based compound. Rated 2,000°F–2,400°F. Copper-free; protects against seizure, galling, galvanic corrosion, and severe environmental corrosion.
- High Temperature Stainless Nuclear Grade: Developed with Electricite de France (EDF) for nuclear applications. Tested per lot for sulfur, halogens, and low-melt metals. Meets GE Nuclear Energy D50YP12. For applications that cannot use nickel-based products.
- Mariner’s Choice: Formulated for salt water, salt air, and high-moisture environments. Rated 2,000°F–2,400°F. Copper-free. Developed with marine engineers for above- and below-waterline use without environmental pollution.
- High Temperature Bearing Lubricant: Combines high-temperature grease and lubricating enhancers. Rated 500°F–1,000°F. Recommended for ball and roller bearings, bushings, and open and sealed bearings under high-pressure, high-temperature conditions.
- White Food Grade with PTFE: All ingredients meet FDA requirements. NSF International H-1 Rating. Rated –5°F–475°F. Virtually odorless, colorless, and tasteless. For food handling plants operating under the Federal Meat and Poultry Products Inspection Program.
- Pipe Compound: Contains PTFE and sealant-enhancing additives for maximum thread lubrication. Rated –50°F–525°F. Copper-, metal-, and graphite-free. Recommended for black iron, galvanized, stainless steel, and high-pressure steam pipes in contact with cast iron, malleable iron, brass, stainless steel, or galvanized fittings.
Why Does Never-Seez Reduce Manufacturing and Maintenance Costs?
Bostik cites three value propositions for Never-Seez: superior part protection, manufacturing cost savings, and rapid part disassembly. On the cost-savings side, the compounds’ spreadability enables up to 6,480 square inches of coverage per pound based on a 4-mil film thickness, reducing the per-joint material cost of corrosion protection.
On the maintenance side, these compounds eliminate the common seizure causes during disassembly — thread distortion, galvanic action, and environmental exposure — allowing parts to be removed without destruction. This reduces downtime, lowers scrap rates, and speeds turnaround on bolted equipment.
When Should You Choose a Copper-Free or Metal-Free Never-Seez Grade?
Several industries and applications prohibit copper, graphite, or all metals in lubricant compounds. Never-Seez addresses this with targeted formulations:
- Copper-free options: Pure Nickel Special, Nickel Nuclear Grade, High Temp Stainless, High Temp Stainless Nuclear Grade, Mariner’s Choice.
- Copper- and graphite-free: Black Moly.
- Fully metal-free: Blue Moly.
- Copper-, metal-, and graphite-free: Pipe Compound.
Nuclear applications additionally require tested purity for sulfur, halogens, and low-melt metals, met by both Nuclear Grade variants with lot-level certification.
Summary
- Never-Seez by Bostik comprises nine grades covering temperatures from –150°F to 2,400°F and pressures up to 500,000 PSI (Black Moly).
- Torque reduction is quantified via a product-specific K-Factor benchmarked against an unlubricated carbon steel baseline of 0.185.
- Coverage reaches up to 6,480 sq. in. per pound at 4-mil film thickness, directly reducing maintenance material costs.
- Copper-free, metal-free, and nuclear-certified grades are available for regulated and sensitive applications, including two variants meeting GE Nuclear Energy D50YP12.
- White Food Grade with PTFE carries NSF H-1 registration for incidental food contact; Pipe Compound contains PTFE for positive sealing on steam and high-pressure pipe systems.
Products discussed in this episode
- Bostik Never-Seez NSN-165 Pure Nickel Special
- Bostik Never-Seez NSB-150 Black Moly – 1 lb Flat Top Can
- Bostik Never-Seez NBBT-8 Blue Moly
- BOSTIK Bostik Never-Seez NSSBT-8 High Temperature Stainless – 8 oz Brush Top Can
- Bostik Never-Seez NMCBT-8 Mariner's Choice
- Bostik Never-Seez NPBT-8 Pipe Compound
Browse all BOSTIK products on PE Energy Industrial Supply.