High-viscosity Base Oil SN 500 is a workhorse feedstock for blending automotive and industrial lubricants.
This guide clarifies specs, Group I vs Group II performance, applications, compliance, and sourcing.

INTRODUCTION

SEO Snippet: A quick, plain-English primer on what Base Oil SN 500 is, where it fits in the base-oil landscape, and why it’s widely used in blended lubricants.

SN 500 is a mid-to-heavy viscosity mineral base oil, classified as solvent-neutral, and widely applied in blending automotive engine lubricants, transmission and gear oils, hydraulic fluids, and a variety of industrial greases. Positioned between lighter grades (e.g., SN 150) and heavier cuts (e.g., SN 600), SN 500 offers a practical balance of viscosity, volatility, and cost for formulators. In today’s lubricants market, you’ll find SN 500 produced as both Group I (solvent-refined) and Group II (hydroprocessed) variants. While both carry the SN 500 viscosity grade label, their refining routes lead to meaningful differences in saturates content, sulfur level, oxidation stability, and low-temperature behavior.

This article breaks down specifications, applications, Group I vs Group II trade-offs, test methods and compliance, plus handling and procurement tips—rounded out with a comprehensive FAQ section.

LSI Keywords: SN500 meaning, SN500 base stock, SN grades, solvent neutral base oil, base oil viscosity, base oil applications, mineral base oil.

External links (kept light for SEO safety):
• <a href="https://www.api.org/" target="_blank" rel="noopener">American Petroleum Institute (API) — specifications & industry programs</a>

BASE OIL SN 500

SEO Snippet: Understand SN 500 fundamentals—viscosity positioning, refining shorthand (“SN”), and what “500” really implies for formulators.

What it is: The “SN” in SN 500 stands for solvent neutral, a legacy refining descriptor. The “500” broadly signals the product’s viscosity cut: a heavier neutral suitable when formulators need higher film thickness and load-carrying potential compared with lighter neutrals like SN 100–150. Practically, formulators rely on SN 500 as a core ingredient in heavier automotive lubricants such as SAE 40 and SAE 50 engine grades, as well as in gear oils, circulating and compressor oils, grease formulations, and certain metalworking blends where a stronger viscosity foundation is required.

Why it matters: Viscosity strongly influences hydrodynamic film formation, friction, and energy loss. SN 500’s viscosity helps maintain protective films at operating temperatures, which is critical in mixed or boundary lubrication regimes. Its volatility is typically lower than lighter cuts, which helps with oil consumption control and flash point targets.

Typical (not guaranteed) characteristics:

• Viscosity range (indicative): KV40 often in the high double-digits to low 100s cSt; KV100 commonly in the low-teens cSt range.
• Viscosity Index (VI): frequently in the ~90–105 range for Group I; often higher for Group II.
• Sulfur & saturates: Group I tends to have higher sulfur and lower saturates than Group II, affecting oxidation stability and color.
• Pour point & volatility: vary by crude source and refinery; Group II often shows better low-temp and volatility metrics.

Always use the supplier’s certificate of analysis (CoA) for exact numbers, since crude selection, refining route, and additive packages influence final properties.

LSI Keywords: SN500 viscosity, heavy neutral base oil, KV100, KV40, viscosity index, solvent neutral oil, base stock properties.

External link:
• <a href="https://www.astm.org/standards/d445" target="_blank" rel="noopener">ASTM D445 — Kinematic Viscosity Test Method</a>

BASE OIL SN 500 GROUP 2

SEO Snippet: Group II SN 500 delivers higher saturates, lower sulfur, and better oxidation stability vs. Group I—often enabling longer oil life.

Refining & composition: Group II base oils are typically hydroprocessed or hydrocracked, yielding high saturates (≥90%) and low sulfur (≤0.03%). For SN 500, this means a cleaner, more stable base compared with Group I in the same viscosity bracket. The improved oxidation stability can enhance deposit control and support longer drain intervals (subject to additive system and OEM approvals).

Performance benefits commonly seen in Group II SN 500:

• Higher oxidation stability → better resistance to thickening/sludge.
• Lower volatility (often) → helps reduce oil consumption and emissions.
• Improved low-temperature fluidity vs. comparable Group I cuts.
• More consistent color and appearance due to lower aromatics and sulfur.

Use cases: Modern diesel and gasoline engine oils, industrial hydraulics targeting tighter cleanliness specs, ashless circulating oils, and anti-wear hydraulic oils. In many formulations, a Group II SN 500 can reduce dispersant/antioxidant loadings or facilitate higher performance classifications—provided base-oil interchange and viscosity-grade read-across rules are satisfied.

Practical caveats: Base oil solvency can be lower in Group II than Group I; some additive packages (especially for greases and metalworking) may rely on Group I aromaticity. Blenders might include a Group I cut or naphthenic component to balance solvency where needed.

LSI Keywords: Group II base oil, hydrocracked base stock, high saturates low sulfur, oxidation stability, volatility control, modern engine oils.

External link:
• <a href="https://www.eia.gov/petroleum/" target="_blank" rel="noopener">U.S. EIA — Petroleum & refining background (market context)</a>

BASE OIL SN 500 GROUP 1

SEO Snippet: Group I SN 500 offers robust solvency and proven blendability, making it valuable for greases, metalworking fluids, and legacy specs.

Refining & composition: Group I base oils are primarily solvent-refined and solvent-dewaxed. Relative to Group II, they generally exhibit higher sulfur, lower saturates, and greater aromaticity. This profile translates into stronger solvency, which helps dissolve certain additive chemistries and improves dye or sealant compatibility in specific legacy formulations.

Where Group I SN 500 shines:

• Grease manufacturing: better thickener wetting and additive solubility.
• Metalworking fluids: improved additive carry and lubricity in some emulsions.
• Industrial oils: where solvency trumps ultra-low sulfur, or where standards allow.
• Cost leverage: Group I can be more cost-effective depending on regional supply.

Trade-offs: Relative to Group II, oxidation stability and volatility may be less favorable in Group I SN 500. Achieving modern engine-oil classifications can require heavier additive treat rates and careful base-oil blending.

LSI Keywords: Group I base oil, solvent refined, aromatic content, grease base oil, metalworking base stock, solvency advantages.

External link:
• <a href="https://www.atiel.org/" target="_blank" rel="noopener">ATIEL — European lubricants industry guidance & base oil interchange concepts</a>

BASE OIL SN 500 SPECIFICATIONS & TYPICAL PROPERTIES

SEO Snippet: How to read SN 500 data sheets: viscosity, VI, pour point, volatility, and why ranges vary by crude source and refinery process.

Reading a data sheet (what to check):

1. Kinematic viscosity (KV40, KV100): Core identifiers for the “500” cut; confirm with ASTM D445.
2. Viscosity Index (VI): Indicates viscosity change with temperature; higher VI supports broader operating windows.
3. Pour point & CCS/MRV (low-temp): Cold-start and pumpability performance; often better in Group II.
4. Noack volatility (ASTM D5800): Lower is better for oil consumption and emissions control.
5. Oxidation & RBOT/ROBOT: Metrics that correlate with deposit control and oil life.
6. Flash point (ASTM D92) & fire point: Safety and volatility indicators.
7. Sulfur & saturates: Proxies for refining severity and cleanliness; important for emissions and catalyst compatibility.
8. Color (ASTM D1500): Aesthetic/quality cue; Group II tends to be lighter (lower number).
9. Neutralization number (TAN): Should be low in well-refined base oils; movement can indicate oxidation.
10. Water (Karl Fischer) & cleanliness (ISO 4406): Crucial for hydraulics and precision systems.

Interpretation tips: Always compare like-for-like test methods, read the latest CoA (not an old generic TDS), and confirm additive compatibility—especially when swapping Group I ↔ Group II.

LSI Keywords: SN500 spec sheet, Noack volatility, pour point, flash point, oxidation stability, TAN, ISO 4406 cleanliness, RBOT.

External links:
• <a href="https://www.astm.org/standards/d5800" target="_blank" rel="noopener">ASTM D5800 — Noack Volatility</a>
• <a href="https://www.iso.org/standard/37311.html" target="_blank" rel="noopener">ISO 4406 — Hydraulic fluid cleanliness code</a>

APPLICATIONS: AUTOMOTIVE & INDUSTRIAL USES OF SN 500

SEO Snippet: Where SN 500 fits—engine oils, gear oils, hydraulic oils, compressor oils, greases, and metalworking fluids.

Automotive engine oils: SN 500 provides the backbone viscosity for many mono-grade and high-viscosity multi-grade blends (e.g., SAE 40/50). With appropriate VI improvers and detergent/dispersant/antioxidant packs, formulators can hit OEM targets for oxidation stability, deposit control, and wear protection.

Gear and transmission oils: Heavier base oils like SN 500 help deliver film strength and scuff protection. Pairing with EP additives (e.g., sulfur-phosphorus chemistries) and suitable friction modifiers can meet GL-class and industrial gear requirements.

Hydraulic & circulating oils: In systems where leakage control and thermal stability are paramount, one advantage of SN 500 is its ability to hold viscosity during operation. When blended with lighter neutral oils, it allows formulators to adjust viscosity grades in anti-wear hydraulic fluids

Compressor & vacuum pump oils: SN 500 is frequently used as a foundation stock in compressor and vacuum pump lubricants, thanks to its balance of oxidation stability and low volatility. Group II variants are especially preferred for minimizing deposit formation.

Greases: Strong solvency (especially Group I SN 500) can improve thickener dispersion (e.g., lithium, calcium complex) and additive wetting, impacting mechanical stability and dropping point.

Metalworking fluids: In metalworking, SN 500 is often chosen for emulsions used in cutting, forming, or rolling processes, as its higher viscosity improves lubricating performance across different metallurgical applications .Emulsifier and biocide compatibility must be validated.

LSI Keywords: engine oil base stock, gear oil base stock, hydraulic oil VG, compressor oil base, grease manufacturing, metalworking lubricants.

External link:
• <a href="https://www.sae.org/standards" target="_blank" rel="noopener">SAE Standards — automotive viscosity & performance frameworks</a>

SN 500 VS SN 150 VS SN 600: CHOOSING THE RIGHT CUT

SEO Snippet: Compare SN 500 to lighter SN 150 and heavier SN 600—how viscosity, volatility, and cost guide your blending choices.

SN 150 (lighter): Lower viscosity simplifies cold-start, improves low-temp pumpability, and can reduce energy losses in hydrodynamic regimes. However, film thickness is lower; blends may need viscosity builders for high-temp protection.

SN 500 (mid-heavy): Balanced choice for film strength and volatility control in many industrial oils and heavier engine oils. It often reduces the amount of VI improver needed vs. starting from SN 150.

SN 600 (heavier): Maximizes film thickness and leakage control but can challenge low-temperature properties and increase energy consumption. Useful in heavy gear oils, certain marine and industrial applications, and high-temp chains.

Decision factors:

• Target viscosity grade (ISO VG or SAE).
• Ambient climate & start-up temps.
• Volatility and emissions constraints.
• Additive solvency needs (consider Group I vs II profile).
• Cost & regional availability.

LSI Keywords: SN150 vs SN500, SN600 vs SN500, base oil selection, viscosity trade-offs, ISO VG alignment, energy efficiency.

External link:
• <a href="https://www.iso.org/home.html" target="_blank" rel="noopener">ISO — Viscosity grade & lubricant classification references</a>

QUALITY STANDARDS, TEST METHODS & COMPLIANCE (ASTM, ISO, REACH)

SEO Snippet: Meet specs with the right tests—ASTM methods, ISO cleanliness, and REACH/OSHA safety compliance for global trade.

Test methods you’ll commonly see on SN 500 TDS/CoA:

• A typical SN 500 datasheet will report viscosity (ASTM D445), viscosity index (ASTM D2270), flash point (ASTM D92), pour point (ASTM D97), volatility (ASTM D5800), acidity and base number (ASTM D2896/D974 and ASTM D664), color (ASTM D1500), and density (ASTM D4052).
• ISO standards for viscosity grades (e.g., ISO 3448), cleanliness (ISO 4406), and sampling/conditioning practices.

Regulatory & safety touchpoints:

• REACH (EU) registration and SDS availability for import/export.
• OSHA hazard communication (U.S.) and GHS classification.
• Transport: check UN classifications if applicable, packaging group, and marine pollutant status.

Documentation checklist: Most buyers request TDS, latest CoA, SDS, REACH (where applicable), and quality certifications (e.g., ISO 9001). For OEM-sensitive applications, when changing suppliers or viscosity ranges, OEM rules for base-oil substitution and grade equivalence must first be checked.

LSI Keywords: ASTM standards for base oil, ISO 3448, REACH registration, SDS safety data sheet, OSHA hazard communication, lubricant compliance.

External links:
• <a href="https://echa.europa.eu/regulations/reach/understanding-reach" target="_blank" rel="noopener">ECHA — Understanding REACH</a>
• <a href="https://www.osha.gov/hazcom" target="_blank" rel="noopener">OSHA — Hazard Communication Standard</a>

PROCUREMENT, PACKAGING, STORAGE & SAFETY

SEO Snippet: Smart buying plus safe storage—how to receive, sample, store, and handle SN 500 to preserve quality and worker safety.

Procurement essentials:

• Source consistency: Resist frequent supplier hopping; crude source and refining route materially impact performance.
• Data verification: Ask for current CoA for each lot, and confirm test methods match your spec.
• Trial blending: Pilot blends to confirm additive solvency, filterability, and foam control when swapping Group I ↔ Group II.

Packaging formats: Bulk, ISO tank, IBC totes, drums. Specify lining compatibility, headspace limits, and cleanliness requirements to prevent contamination.

Storage practices:

• Keep tanks dry and sealed; use desiccant breathers where humidity is high.
• Maintain transfer cleanliness (filters, hoses, sample ports).
• Control temperature to avoid wax precipitation (Group I) or condensation.
• Adopt FIFO and regularly test water content and particulate.

Safety & handling:

• Review SDS and train teams in PPE, spill response, and fire safety.
• Manage hot work and static discharge risks during transfers.
• Confirm waste oil handling meets local environmental regulations.

Market dynamics to watch: Regional refinery turnarounds, feedstock spreads, shipping constraints, and seasonal demand (e.g., agricultural and marine cycles) can influence lead times and price negotiations.

LSI Keywords: SN500 procurement, base oil storage, IBC drum handling, SDS safety, CoA verification, desiccant breather, contamination control.

External link:
• <a href="https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications" target="_blank" rel="noopener">API — Engine oil categories & classifications (context for base oil roles)</a>

FREQUENTLY ASKED QUESTIONS (FAQS)

SEO Snippet: Concise responses to the most relevant queries, covering sourcing, technical performance, compatibility with lubricants, and industry standards.

Q1. Is SN 500 a Group I or Group II base oil?
Both exist. “SN 500” defines viscosity; Group I vs Group II defines refining and chemistry (sulfur/saturates/VI), which influences performance.

Q2. Can I replace Group I SN 500 with Group II SN 500 one-for-one?
Not always. Group II often has better oxidation stability and lower volatility but lower solvency. Validate additive compatibility and observe base-oil interchange rules.

Q3. What’s the typical viscosity of SN 500?
Expect a mid-heavy neutral: KV40 in the high double-digits to low 100s cSt and KV100 commonly in the low-teens cSt. Always confirm with the supplier’s CoA.

Q4. Where is SN 500 used most?
Engine oils (especially higher SAE grades), industrial gear oils, hydraulic/circulating oils, greases, and metalworking fluids.

Q5. Does Group II SN 500 improve oil life?
Often yes, thanks to higher saturates and lower sulfur, which bolster oxidation stability—subject to additive system and duty cycle.

Q6. Why is solvency important?
Additives, dyes, and some thickeners dissolve and function differently depending on base-oil aromaticity. Group I SN 500 typically offers better solvency.

Q7. What test methods should I require from a supplier?
At minimum: ASTM D445 (viscosity), D2270 (VI), D92 (flash), D97 (pour point), D5800 (Noack), D1500 (color), D4052 (density), and cleanliness/water as applicable.

Q8. How do I store SN 500 to prevent issues?
Use clean, dry tanks, minimize headspace, control temperature, install desiccant breathers, and monitor water/particulate.

Q9. What’s the difference between SN 500 and SN 600?
SN 600 is heavier—more film strength but poorer low-temp behavior and potentially higher energy draw. Choose based on VG/SAE target and climate.

Q10. Does SN 500 meet modern OEM engine oil specs by itself?
No. Base oil is only part of the formulation. You need additive packages and VI improvers, plus proper testing and approvals.

Q11. Are there environmental or regulatory concerns?
Yes—ensure REACH (where relevant), SDS accuracy, local waste management compliance, and safe handling per OSHA/GHS.

Q12. How do I compare suppliers fairly?
Request the same test slate, same units/methods, fresh CoA, review stability/volatility, and run pilot blends before full adoption.

LSI Keywords: SN500 questions, Group I vs Group II FAQ, SN500 CoA, SN500 storage FAQ, ASTM tests for base oil, OEM approvals, oxidation stability FAQ.

External links:
• <a href="https://echa.europa.eu/support/registration" target="_blank" rel="noopener">ECHA — REACH registration support</a>
• <a href="https://www.astm.org/get-involved/technical-committees/d02-petroleum-products-liquid-fuels-and-lubricants" target="_blank" rel="noopener">ASTM D02 Committee — Petroleum products & lubricants</a>

CONCLUSION

SEO Snippet: SN 500 is a flexible mid-to-heavy base stock. Recognizing the distinctions between Group I and Group II grades helps formulators optimize solvency, thermal stability, and cost efficiency in their blends.

Base Oil SN 500 remains a cornerstone for automotive and industrial lubricants. Selecting the right viscosity cut is essential: Group I is preferred where solvency and additive response are critical, while Group II is chosen for cleaner performance, lower volatility, and superior oxidation resistance. By standardizing on reputable test methods (ASTM/ISO), validating additive compatibility, and enforcing clean storage and handling, buyers can optimize cost, reliability, and product performance. When switching suppliers or Group categories, reduce risk with pilot blends and side-by-side CoA comparisons.

LSI Keywords: SN500 buyer’s guide, base oil formulation, CoA vs TDS, lubricant quality, industrial oils, OEM approvals, hydroprocessing vs solvent refining.

External link:
• <a href="https://www.iso.org/committee/45402.html" target="_blank" rel="noopener">ISO TC 28 — Petroleum and related products</a>