40/50 Penetration Bitumen Specification
Last updated: 2026-10-01
40/50 Penetration Bitumen Specification
40/50 penetration bitumen is a standard paving-grade bitumen with a needle penetration of 40–50 dmm (0.1 mm) at 25°C, a softening point of 50–58°C, and a kinematic viscosity of at least 320 cSt at 135°C. It is harder than the more common 60/70 grade, making it suited to hot climates, heavy-traffic highways, and industrial applications where rutting resistance matters more than low-temperature flexibility. Typical export pricing in 2024–2025 ranges from $420 to $520 per metric ton FOB, depending on origin (Middle East, Southeast Asia, or Iran) and packaging (bulk, new steel drums, or jumbo bags).
This article breaks down the full 40/50 penetration bitumen specification, compares it against 60/70 and 80/100 grades, and explains how to verify a supplier's test certificate before you commit to a 500–5,000 MT order.
What Is the 40/50 Penetration Bitumen Specification?
Penetration grading measures hardness by dropping a standard needle into a bitumen sample under fixed conditions (25°C, 100 g load, 5 seconds). A 40/50 grade means the needle penetrates between 40 and 50 tenths of a millimeter. Lower numbers = harder bitumen = higher resistance to deformation under load.
The core specification parameters are defined under ASTM D946 (Standard Specification for Penetration-Graded Asphalt Cement) and its equivalents EN 12591 (Europe) and IS 73 (India). Here is the full technical breakdown:
| Property | Test Method | 40/50 Value Range |
|---|---|---|
| Penetration @ 25°C, 100g, 5s | ASTM D5 / EN 1426 | 40–50 dmm |
| Softening Point (Ring & Ball) | ASTM D36 / EN 1427 | 50–58°C |
| Kinematic Viscosity @ 135°C | ASTM D2170 | ≥ 320 cSt |
| Flash Point (Cleveland Open Cup) | ASTM D92 | ≥ 250°C |
| Solubility in Trichloroethylene | ASTM D2042 | ≥ 99.0% |
| Density @ 25°C | ASTM D70 | 1.01–1.06 g/cm³ |
| Penetration Index (PI) | Calculated | –1.0 to +1.0 |
| Loss on Heating (5h @ 163°C) | ASTM D1754 | ≤ 0.8% by mass |
| Retained Penetration after RTFOT | ASTM D5 | ≥ 55% of original |
| Ductility @ 25°C | ASTM D113 | ≥ 50 cm |
Key point for buyers: The softening point is the single most important number after penetration. A 40/50 grade below 50°C softening point will rut in summer heat above 35°C ambient. Always demand a batch-specific Certificate of Analysis (COA), not a generic spec sheet.
At 135°C, 40/50 bitumen must flow at ≥ 320 cSt for proper pumping and mixing at the asphalt plant. If a supplier ships material at 280 cSt, you will see incomplete coating of aggregate, higher mixing temperatures, and premature aging. Viscosity is also the fastest way to detect cutback or flux contamination — a common issue in re-labeled Iranian or Iraqi cargo.
40/50 vs 60/70 vs 80/100: Direct Comparison
Most global buyers default to 60/70 penetration grade because it balances cost and performance. But 40/50 wins in specific scenarios. Here is the side-by-side:
| Parameter | 40/50 | 60/70 | 80/100 |
|---|---|---|---|
| Penetration @ 25°C (dmm) | 40–50 | 60–70 | 80–100 |
| Softening Point (°C) | 50–58 | 45–52 | 42–48 |
| Viscosity @ 135°C (cSt) | ≥ 320 | ≥ 240 | ≥ 180 |
| Climate Suitability | Hot (>30°C avg) | Moderate | Cold/temperate |
| Rutting Resistance | Excellent | Good | Moderate |
| Low-Temp Cracking Risk | Higher | Moderate | Low |
| Typical FOB Price (USD/MT) | $420–520 | $390–470 | $370–440 |
| Best For | Heavy traffic, ports, airports | General highways | Cold regions, low-volume roads |
Practical rule: If your project's maximum pavement temperature exceeds 58°C (PG 64 or higher climate), specify 40/50. For moderate climates (PG 58), 60/70 is more cost-effective. For anything below PG 52, use 80/100 or a polymer-modified binder.
- 40/50 Penetration Bitumen: Airport runways, container terminal aprons, steep gradients, bus lanes, heavy truck corridors, hot-climate motorways (Middle East, North Africa, South Asia, parts of Latin America)
- 60/70 Penetration Bitumen: Standard national highways, urban arterials, moderate climates
- 80/100 Penetration Bitumen: Cold-climate roads, secondary roads, chip seals, tack coats
Performance Data: How 40/50 Behaves in Real Projects
Specification numbers only tell part of the story. Field performance data from hot-climate projects shows measurable differences:
| Performance Metric | 40/50 Result | 60/70 Result | Test Condition |
|---|---|---|---|
| Wheel tracking rate (mm/hr) | 0.08–0.12 | 0.15–0.22 | 60°C, 700 kPa |
| Dynamic stability (cycles/mm) | 3,500–4,800 | 2,200–3,200 | 60°C slab test |
| Fatigue life (cycles to failure) | 1.8M | 1.5M | 20°C, 400 µε |
| Rut depth after 20,000 passes | 3.2 mm | 6.8 mm | 60°C |
| Mixing temperature | 155–165°C | 150–160°C | Plant trial |
The 3.6 mm rut reduction after 20,000 wheel passes is the headline number for highway agencies in the Gulf, North Africa, and South Asia. That difference translates to 2–4 additional years of service life on heavy-traffic corridors before major rehabilitation.
- Mixing temperature: 155–165°C (10–15°C higher than 60/70 due to higher viscosity)
- Storage temperature: 140–150°C with continuous circulation; do not hold above 170°C for more than 48 hours
- Maximum storage duration: 7–10 days at temperature before properties begin to drift
- Drums: 150 kg or 182 kg new steel drums are the export standard; jumbo bags (1 MT) suit bulk vessel shipments
Price, Packaging, and Shipping: What Importers Pay
40/50 commands a premium of $25–50 per MT over 60/70 in most markets because fewer refineries produce it and demand concentrates in high-value infrastructure projects.
| Origin | FOB Price (USD/MT) | Drums per 20ft Container | MT per 20ft Container |
|---|---|---|---|
| UAE (Jebel Ali) | $450–520 | 110 (150 kg) | 16.5 |
| Bahrain | $440–500 | 110 | 16.5 |
| Iran (Bandar Abbas) | $420–480 | 110 | 16.5 |
| Singapore | $470–540 | 110 | 16.5 |
| South Korea | $460–530 | 110 | 16.5 |
Shipping logistics:
- 20ft container: 110 drums × 150 kg = 16.5 MT (this is the global standard)
- Flexitank in 20ft: 22–24 MT (cheaper per MT but higher contamination risk)
- Bulk vessel: 1,000–30,000 MT (best per-MT cost, needs heated discharge facilities)
- Lead time: 7–14 days for drumming after order confirmation, 18–35 days transit depending on route
Payment terms: 100% LC at sight is standard for first orders; 30% TT advance + 70% against B/L copy after 2–3 successful shipments.
- COA lists softening point below 49°C but claims 40/50 grade
- Viscosity value missing or listed as "by calculation"
- Penetration tested at 15°C instead of 25°C
- No RTFOT retained penetration data
- Drum markings don't match the COA batch number
How to Verify 40/50 Penetration Bitumen Quality Before Shipment
Third-party inspection is non-negotiable for orders above 100 MT. The standard protocol:
1. Pre-shipment sampling — SGS, Intertek, or Bureau Veritas draws samples from 10% of drums minimum
2. Witness testing — penetration, softening point, viscosity, flash point at an accredited lab
3. Seal retention — inspector seals sampled drums; retain samples for 6 months
4. COA cross-check — compare refinery COA against independent results; variance above 5% triggers rejection
5. Drums and markings — verify batch numbers, net weight (150 kg ± 2%), and lining integrity
Cost of inspection: $800–1,500 per shipment. Cost of a rejected 500 MT cargo: $200,000+. The math is obvious.
Load port tolerance: Most contracts allow ±2% on quantity and require the seller to bear inspection costs if material fails specification at load port.
FAQ: 40/50 Penetration Bitumen Specification
What is the difference between 40/50 and 60/70 penetration bitumen?
40/50 bitumen is harder, with a penetration of 40–50 dmm versus 60–70 dmm for 60/70 grade, and a softening point roughly 5°C higher. It resists rutting better in hot climates but is less flexible at low temperatures. It typically costs $25–50 more per metric ton.
What is the softening point of 40/50 penetration bitumen?
The softening point ranges from 50°C to 58°C under ASTM D36 (Ring & Ball method). Values below 50°C usually indicate contamination or mislabeling. Values above 58°C may suggest over-blowing or polymer addition.
How many metric tons fit in a 20ft container of 40/50 bitumen?
A standard 20ft container holds 110 new steel drums at 150 kg each, totaling 16.5 metric tons. Some suppliers use 182 kg drums, but this risks exceeding container weight limits in certain jurisdictions.
Which standard covers 40/50 penetration bitumen?
ASTM D946 covers it in the US, EN 12591 in Europe, and IS 73 in India, with minor tolerance differences between them. Most export contracts reference ASTM D946 or a project-specific specification derived from it. Always confirm which standard applies before signing.
What is the price of 40/50 penetration bitumen in 2025?
FOB prices range from $420 to $540 per metric ton depending on origin, packaging, and order volume. Middle Eastern origins (UAE, Bahrain, Iran) are typically cheapest, while Singapore and South Korean material carries a $20–50 premium. Bulk vessel orders above 5,000 MT can negotiate $15–30 per MT lower.
Calculate Your Exact 40/50 Bitumen Cost in 60 Seconds
Specification is only half the decision — landed cost is the other half. Drum costs, freight, insurance, inspection, port charges, and customs duties can add $80–180 per MT to the FOB price. Guessing at these numbers costs importers tens of thousands of dollars per shipment.
Use the 6Tar cost calculator to get a landed-cost breakdown for your exact route, volume, and packaging mix. Enter your port pair, tonnage (16.5 MT container or bulk), and payment terms — the calculator returns a per-MT delivered cost you can drop straight into your tender documents.
Start your 40/50 bitumen quote now — get FOB and CIF pricing for your destination port in under 60 seconds.