Industrial Lubricant Procurement Guide Thailand — How to Select and Buy the Right Oil

Why Procurement Teams Must Understand Lubricant Specifications

In many Thai factories, the purchasing department orders lubricants based on "the brand we always use" or "cheapest price available" — without verifying whether the specification actually matches the machine requirements. The result: accelerated wear, ballooning maintenance costs, and sometimes unplanned production shutdowns.

Repairing a gearbox destroyed by an incorrect oil grade typically costs 10–30 times more than a full year's oil supply for that machine. Correct procurement therefore does not mean "buy the cheapest" — it means "buy to specification, in the right quantity, at a competitive price."

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Part 1: Selecting Oil Type by Machine

ISO VG Selection Table by System and Operating Temperature

System Type	Reference Standard	ISO VG (Normal ambient 25–40°C)	ISO VG (High ambient >40°C)	Notes
Hydraulic — low pressure (<100 bar)	ISO 6743-4 / DIN 51524-1 (HL)	VG 32–46	VG 46–68	CNC machines, injection molding
Hydraulic — high pressure (100–350 bar)	ISO 6743-4 / DIN 51524-2 (HM)	VG 46	VG 68	Standard for most Thai factories
Gear — helical/spur (high speed)	ISO 12925-1 / DIN 51517-3 (CLP)	VG 150–220	VG 220–320	Gearboxes at 750–1,500 RPM
Gear — worm gear	ISO 12925-1 / AGMA 9005	VG 220–320	VG 320–460	Requires EP (extreme pressure)
Compressor — rotary screw	ISO 6743-3A (DAA/DAB)	VG 32–46	VG 46	Change every 2,000–4,000 hours
Compressor — reciprocating	ISO 6743-3A (DAA)	VG 68–100	VG 100–150	Must withstand higher temperatures
Slideway (machine tool guideways)	ISO 6743-13 (G or F)	VG 68–220	VG 220	Requires stick-slip protection
Bearing — high speed	ISO 6743-9 / DIN 51825 (KA)	NLGI 1–2	NLGI 2	Select thickener by temperature
Bearing — heavy load	ISO 6743-9 / DIN 51825 (KE/KF)	NLGI 2–3	NLGI 2–3 EP	EP additive required

Values above are starting points — always verify against OEM manual. ISO VG measured at 40°C per ISO 3448.

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Key Application Descriptions

Hydraulic systems are the most common in Thai factories (forklifts, presses, CNC machines). They require oils with Anti-Wear (AW) additives to protect pumps and valves. Oil passing DIN 51524-2 (HL or HM) is a safe baseline specification.

Gear oils require Extreme Pressure (EP) additives — typically sulfur-phosphorus compounds. DIN 51517-3 (CLP) is the standard for enclosed gears; ISO 12925-1 provides the international classification framework.

Compressor oils have unique requirements: they must withstand high operating temperatures without forming carbon deposits in valves. Rotary screw and reciprocating compressors use different oil types. Never substitute hydraulic oil in a compressor.

Slideway oils require tackiness additives to prevent stick-slip — enabling smooth, judder-free machine movement. Do not substitute gear oil, as EP additives in gear oils can corrode guideway surfaces.

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Part 2: Mineral vs Synthetic — The Real TCO Comparison

One of the most common buyer questions is: "Synthetic costs 3–5× more than mineral. Is it worth it?"

The answer depends on Total Cost of Ownership (TCO), not just price per litre.

Factor	Mineral Oil	Full Synthetic Oil
Price per litre (approximate)	฿100–200	฿300–600
Change interval	1,000–2,000 hrs	4,000–8,000 hrs
Annual volume consumption	2–4× more	Less
Energy efficiency	Baseline	2–8% reduction (higher VI)
High temperature resistance	Moderate (< 80°C)	Excellent (> 100°C)
Oxidation stability	Moderate	Significantly higher
Downtime reduction	—	15–30% reduction
TCO per operating hour	Baseline	15–40% lower for heavy duty

Practical conclusions:

• Light to medium duty, normal temperatures: Mineral is adequate and more economical in the short term.
• 2–3 shift operations, sustained high temperatures, or high-value machinery: Synthetic pays back within 12–24 months.
• New machinery where OEM specifies Synthetic: Must comply with spec — using mineral may void the warranty.

Semi-Synthetic: The Middle Path

Semi-Synthetic (Group II / Group III base stocks) offers a cost-effective middle ground for many operations:

• 20–40% lower cost than Full Synthetic
• 50–100% longer change intervals than Mineral
• Suitable for medium-to-heavy duty applications where maximum performance is not required

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Part 3: Decision Tree — Selecting Oil by Machine

flowchart TD
    A["Identify machine type"] --> B{Is it a hydraulic system?}
    B -->|Yes| C{Maximum system pressure?}
    C -->|"< 100 bar"| D["ISO VG 32–46\nDIN 51524-1 (HL)"]
    C -->|"100–350 bar"| E["ISO VG 46–68\nDIN 51524-2 (HM)"]
    C -->|"> 350 bar"| F["ISO VG 68–100\nDIN 51524-2 HV or HVLP"]
    B -->|No| G{Is it a gear / gearbox system?}
    G -->|Yes| H{Gear type?}
    H -->|"Helical / Spur"| I["ISO VG 150–320\nDIN 51517-3 CLP-EP"]
    H -->|"Worm Gear"| J["ISO VG 220–460\nHigh temp → consider Synthetic"]
    G -->|No| K{Is it a compressor?}
    K -->|"Rotary Screw"| L["ISO VG 32–46\nISO 6743-3A DAA/DAB"]
    K -->|"Reciprocating"| M["ISO VG 68–150\nISO 6743-3A DAA"]
    K -->|No| N{Bearing or Slideway?}
    N -->|"Bearing"| O{Speed and load?}
    O -->|"High speed, light load"| P["NLGI 1–2\nDIN 51825 KA/KB"]
    O -->|"Low speed, heavy load"| Q["NLGI 2–3 EP\nDIN 51825 KE/KF"]
    N -->|"Slideway (guideways)"| R["ISO VG 68–220\nISO 6743-13 G"]

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Part 4: Storage and Handling

Improper storage degrades oil before it ever reaches the machine. Key steps for procurement and warehouse teams:

Storage Principles

• Temperature: Store at 10–35°C, away from direct sunlight. Never leave drums outdoors — UV and heat accelerate oxidation.
• Moisture: Oil absorbs moisture from the air. Always close drum caps securely when not in use. Store 200L drums on their side (bung on the side, not facing up) to prevent moisture ingress through the cap seal.
• Cross-contamination: Use dedicated dispensing equipment for each oil type. Never share funnels, pumps, or measuring containers between different lubricants — cross-contamination degrades additive packages.
• FIFO (First In, First Out): Always use older stock first. Mineral oils typically have a 3–5 year shelf life; synthetics 5–7 years from manufacture date.
• Labeling: Mark every drum and container with type, ISO VG grade, and date received.

Dispensing Equipment

Container Size	Recommended Equipment
200L Drum	Drum pump with metered dispensing nozzle and hose
18L Pail	Dedicated stainless measuring cup + pour strainer
1–4L Bottle	Direct fill with fold-flat filter funnel

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Part 5: Ordering Checklist — What to Tell Your Supplier

To ensure you receive the correct oil at a fair price, prepare the following information before placing an order:

Essential information (required)

• System type: hydraulic / gear / compressor / bearing / other
• ISO VG grade required (or machine model and OEM manual for supplier recommendation)
• Mineral, Semi-Synthetic, or Full Synthetic
• Quantity required (litres / 18L pails / 200L drums)
• Required approvals or standards, e.g. DIN 51524-2, ISO 11158 HM, Bosch Rexroth RE 90220

Additional information for more precise recommendations

• Machine make and model (e.g. Bosch Rexroth A10V, SMC Pneumatics)
• System operating temperature range (e.g. oil runs at 60–80°C)
• Plant environment: ambient temperature / presence of water or chemical contamination
• Desired change interval (e.g. must achieve 2,000 hours minimum)
• Operating hours per day (1 shift / 2 shifts / 3 shifts) — directly impacts TCO

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Part 6: Pricing and Procurement Planning

Industrial lubricant prices in Thailand fluctuate with crude oil prices and exchange rates. Factors that affect your cost per litre:

Cost-reduction factors (how to get better pricing)

• Buy in 200L drums instead of 18L pails — saves 15–25% per litre
• Purchase larger quantities 3–6 months forward when crude prices are low
• Use Synthetic to reduce change-out frequency, even though per-litre cost is higher
• Order from suppliers with in-country stock to avoid import delays and surcharges

Cost-increasing factors (to avoid)

• Frequent brand switching, requiring full system flushing each time (flushing oil + downtime)
• Over-stocking beyond 3 months of consumption — risk of oil exceeding shelf life
• Buying on lowest price alone without specification verification — machine damage costs many times more

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Summary: Professional Lubricant Procurement in Six Steps

1. Consult OEM manual — identify ISO VG grade, oil type (HM/CLP/DAA etc.), temperature range
2. Evaluate TCO — compare Mineral vs Synthetic based on annual operating hours and maintenance costs
3. Select a brand with matching approvals — always request a Technical Data Sheet (TDS)
4. Calculate the right quantity — stock 1–2 months of consumption; avoid holding more than 3 months
5. Set change intervals — record in Maintenance Log and track against actual machine condition
6. Review annually — machine load profiles change; re-evaluate lubricant grade each year

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Calculate Your Lubricant Costs in Advance

Want to compare Mineral vs Synthetic costs for your specific machines? Use our calculator:

Lubricant Cost Calculator →

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Get a Quote

Sahawatthanakit (1988)'s engineering team is ready to help you select the correct lubricant specification for your machinery. Send us your machine model, OEM manual, or operating conditions — we'll analyse and recommend before you order, at no charge.

• LINE OA: @406rrgvm
• Email: info@sahawatthanakit1988.com
• Tel: 02-096-2118

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