Oxidized bitumen 90/10 is an unusual grade and the reason is in the numbers. At 85 to 95 °C softening point with only 5 to 15 dmm penetration, it is harder than 105/15 while sitting 15 °C lower on the softening scale. Most blown grades trade hardness against heat resistance in a predictable ratio. 90/10 breaks that pattern — and that is exactly why pipe coating specifications keep asking for it.
RAHA Gilsonite supplies oxidized bitumen 90/10 against ASTM D312, BS EN 13304:2009 or a buyer’s own specification, with a batch certificate of analysis issued before loading. This page covers the specification, why the hardness-to-softening-point ratio is the point of the grade, melting and application temperatures, and where 90/10 belongs against the alternatives.
What is oxidized bitumen 90/10?
Oxidized bitumen, also called blown bitumen or blown asphalt, is produced by blowing air through hot penetration grade bitumen at around 240 to 260 °C. Oxygen reacts with the maltene fraction and converts it toward asphaltenes. The binder becomes harder, the softening point climbs and the penetration falls.
Reading the designation
The grade name reads softening point over penetration. In oxidized bitumen 90/10, the 90 is the ring-and-ball softening point in degrees Celsius and the 10 is the penetration at 25 °C in tenths of a millimetre — meaning a standard needle sinks only 1 mm under defined test conditions. Under BS EN 13304:2009, oxidised grades are expressed as multiples of 5, so 90/10 is a standard-defined grade within that European framework.
Why 90/10 does not follow the usual pattern
Across most of the blown range, softening point and hardness move together. 85/25 is softer than 95/25, which is softer than 115/15. The harder you blow, the higher both figures climb.
90/10 sits outside that. It carries the penetration of a very hard grade with the softening point of a mid-range one. That combination comes from the feedstock and the blowing profile rather than simply from blowing longer — a different crude cut, blown under different conditions, produces a tighter asphaltene network at a lower softening point.
The practical effect is a binder that resists deformation under sustained load extremely well without needing the very high application temperatures that 115/15 or 150/5 demand.
Where that matters. A buried pipeline sits in ground that rarely exceeds 30 °C, so 115 °C of softening point is wasted margin. What the coating actually needs is resistance to creep under soil pressure and mechanical damage during backfill — both functions of hardness, not heat resistance. 90/10 delivers the hardness at a lower melting temperature and a lower price.
Oxidized bitumen 90/10 specification
| Property | Unit | Specification | Typical result | Test method |
|---|---|---|---|---|
| Softening point (ring & ball) | °C | 85–95 | 90 | ASTM D36 / EN 1427 |
| Penetration @25 °C, 100 g, 5 s | dmm | 5–15 | 10 | ASTM D5 / EN 1426 |
| Loss on heating | wt % | 0.5 max | 0.2 | ASTM D6 |
| Flash point (Cleveland open cup) | °C | 245 min | 270 | ASTM D92 |
| Solubility in trichloroethylene | wt % | 99 min | 99.5 | ASTM D2042 |
| Specific gravity @25 °C | — | 1.00–1.06 | 1.04 | ASTM D70 |
| Ductility @25 °C | cm | Report | 1–2 | ASTM D113 |
| Ash content | wt % | 0.5 max | 0.2 | ASTM D2939 |
| Spot test | — | Negative | Negative | AASHTO T102 |
Ductility is reported rather than specified. At 10 dmm the material fractures rather than stretching, so the figure is informative only. Test methods are maintained by ASTM International. Where a project names a specification that differs from the values above, send us the specification rather than the grade name and we will confirm what meets it.
Applications of oxidized bitumen 90/10
Every application below needs hardness and creep resistance rather than extreme heat resistance. That distinction is what separates 90/10 from the 105 and 115 series.
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Pipe coating enamel
The dominant use. Hot-applied anti-corrosion enamel for buried steel pipeline, blended with filler and reinforced with glass wrap. Ground temperature is stable, so hardness matters more than softening point.
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Cable and duct filling
Filling compounds for cable joints, ducts and electrical enclosures where the compound must not creep out over years of service.
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Industrial mastic and flooring
Heavy-duty jointing and levelling compounds for plant floors and industrial substrates that carry sustained static load.
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Tank base and bund lining
Bituminous lining under storage tanks and within bunds, where chemical resistance and dimensional stability govern.
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Marine and harbour mastic
Jointing and sealing compounds for port structures, where salt exposure and static load combine.
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Chemical-resistant compounds
Formulations needing resistance to acids, alkalis and salts, in tank lining and process plant applications.
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Briquette and carbon binder
Binder for coal and charcoal briquettes where the material must hold shape through curing without flowing.
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Roofing primer and base coat
Priming and base layers beneath membrane — a different function from the membrane coating itself.
Where 90/10 is the wrong grade
Do not use 90/10 as a membrane or roofing felt coating. At 10 dmm the sheet cracks at the fold and fails at the lap. That work belongs to 90/40, 85/25 or 105/35 depending on climate.
Equally, do not specify it where service temperature is genuinely extreme. An exposed installation in Gulf summer sun can exceed the 85 to 95 °C softening band. For that, 115/15 or 150/5 give the necessary margin.
The three grades that share 90 °C
90/10, 90/15 and 90/40 all sit in the same 85 to 95 °C softening band. The penetration runs from 10 dmm to 40 — a factor of four. Ordering by softening point alone across these three is the most direct route to a failed batch.
| 90/10 | 90/15 | 90/40 | |
|---|---|---|---|
| Penetration | 5–15 dmm | 10–20 dmm | 35–45 dmm |
| Behaviour at ambient | Hard, fractures under bending | Firm, limited flex | Flexible, folds without cracking |
| Creep resistance | Highest of the three | Good | Limited |
| Suits pipe coating | Yes — the standard choice | Acceptable | Wrapping tape only |
| Suits membrane | No | Marginal | Yes |
| Suits static sealing | Yes | Yes | Only where the joint moves |
| Melting temperature | 175–200 °C | 170–195 °C | 160–185 °C |
90/10 against 105/15 and 115/15
These are the three grades a pipe coating specification usually shortlists.
| 90/10 | 105/15 | 115/15 | |
|---|---|---|---|
| Softening point | 85–95 °C | 100–110 °C | 110–120 °C |
| Penetration | 5–15 dmm | 10–20 dmm | 10–20 dmm |
| Hardest of the three | Yes | No | No |
| Application temperature | 190–215 °C | 200–225 °C | 200–225 °C |
| Best for buried pipe | Temperate and cool ground | Warm ground, general | Hot climates, exposed sections |
| Relative cost | Lowest | Middle | Highest |
For pipeline buried in ground that stays below about 35 °C, 90/10 delivers the hardness the coating needs without paying for softening point that will never be used. Where the line runs above ground, crosses hot desert, or the specification names a higher service temperature, move up the range.
How 90/10 compares with the full oxidized range
| Grade | Softening point | Penetration | Class | Principal use |
|---|---|---|---|---|
| 150/5 | 145–155 °C | 0–10 dmm | Hardest | Electrical compounds, battery sealing, pipe enamel, rubber |
| 115/15 | 110–120 °C | 10–20 dmm | Hard | Waterproofing, adhesives, sealing, pipe coating in hot climates |
| 105/35 | 100–110 °C | 30–40 dmm | Medium | Membrane for hot climates |
| 105/15 | 100–110 °C | 10–20 dmm | Hard | Sealing, jointing, industrial mastics, pipe coating |
| 95/25 | 90–100 °C | 20–30 dmm | Medium | Membrane and damp proofing in warm markets |
| 90/40 | 85–95 °C | 35–45 dmm | Softer | Membrane for temperate and cool climates |
| 90/15 | 85–95 °C | 10–20 dmm | Medium | Adhesive and sealing work |
| 90/10 | 85–95 °C | 5–15 dmm | Hard | Pipe coating, cable filling, industrial mastics, tank lining |
| 85/40 | 80–90 °C | 35–45 dmm | Softer | Membrane and DPC in cold climates |
| 85/25 | 80–90 °C | 20–30 dmm | Medium | The volume roofing grade worldwide |
| 75/35 | 70–80 °C | 30–40 dmm | Softest | Damp proofing, low-temperature climates |
| 75/25 | 70–80 °C | 20–30 dmm | Softest | General waterproofing, jointing |
The full range is listed on our oxidized bitumen grades page.
Melting and application temperatures
| Operation | Temperature | Notes |
|---|---|---|
| Melting | 175–200 °C | Indirect heating only. Melt the full charge and homogenise before drawing off |
| Pumping | 185–205 °C | Lines and pumps must be heat traced or the material will set in them |
| Application / blending | 190–215 °C | Pipe coating lines typically run at the upper end for even film build |
| Absolute maximum | 225 °C | Above this the material cokes, fumes heavily and the softening point drifts |
| Hot holding | Not recommended | Melt per batch. Prolonged holding hardens the grade further |
A practical advantage over the harder grades. 90/10 works at 10 to 25 °C lower than 115/15 or 150/5. On a pipe coating line running continuously, that difference shows up in fuel consumption, fume generation and operator safety margin. Where the specification allows either grade, the lower working temperature is a real operational benefit rather than a technical compromise.
Safety
The flash point is 245 °C minimum, so there is margin against the working range, but fume generation and thermal burn risk are real at these temperatures. Because bitumen is a poor conductor of heat, the melting phase must be controlled to prevent localised overheating. If the material foams, spits or crackles as it heats, water is present — stop heating rather than trying to drive it off. Handling guidance is published by Eurobitume and the Asphalt Institute.
Packing, storage and shipping
| Packing | Unit weight | Per 20′ container | Notes |
|---|---|---|---|
| Kraft paper bag | 25 kg | Up to 25 MT palletised | Most common. Meltable bag options available so the bag goes into the melter |
| PP bag | 25 kg | Up to 25 MT palletised | Palletised and shrink wrapped |
| Carton box | 25 kg | Up to 22 MT | Better protection for long transit and rough handling |
| New steel drum | 180–190 kg | 80 drums ≈ 15 MT | Requires cutting or a drum melter at destination |
Storage and shelf life
Two to three years in sealed packing kept dry and out of direct sun. Because the material is already fully blown there is little left for atmospheric oxygen to react with, so chemical ageing runs slowly.
90/10 is among the easiest blown grades to store. At 10 dmm the blocks stay rigid and stack fusion is rarely a problem even in tropical container temperatures. The usual precautions still apply: pallets, under cover, no more than two tiers, batch number filed with the certificate of analysis.
Customs classification
The grade falls under HS 2713.20, petroleum bitumen. Bagged and drummed material at ambient temperature is generally not classified as dangerous goods for sea carriage, although most shipping lines and destination customs still require the safety data sheet with the booking. Note that gilsonite and other natural bitumen fall under a different heading.
Quality control and certification
Every shipment leaves with a batch certificate of analysis stating the lot number, the production date, the standard tested against and each test with its method and measured result. We accept third-party inspection at loading by SGS, Bureau Veritas, Intertek or any surveyor named in your contract.
What to check for this grade
Check the penetration figure carefully. The 5 to 15 dmm window is wide relative to the value — a batch at 14 dmm is nearly three times softer than one at 5. For pipe coating, where creep resistance is the whole reason for the specification, that difference is material. If your line is sensitive, contract to a narrower band such as 8 to 12 dmm rather than accepting the full range.
Also confirm the softening point sits where you expect. A batch at 94 °C behaves closer to 95/25 territory in terms of heat margin, which may be an advantage or may indicate the blowing ran differently from the norm.
Frequently asked questions about oxidized bitumen 90/10
What does 90/10 mean in oxidized bitumen?
The first number is the ring-and-ball softening point in degrees Celsius, so approximately 90 °C. The second is the penetration at 25 °C in tenths of a millimetre, so approximately 10 dmm — a standard needle sinks only 1 mm. The specification runs 85–95 °C for softening point and 5–15 dmm for penetration.
What is oxidized bitumen 90/10 used for?
Principally pipe coating enamel for buried steel pipeline, plus cable and duct filling compounds, industrial mastics and flooring, tank base and bund lining, marine and harbour mastic, chemical-resistant compounds, briquette binders, and roofing primers and base coats. All of these need hardness and creep resistance rather than extreme heat resistance.
Why is 90/10 harder than 105/15 despite the lower softening point?
Because softening point and penetration do not always move together. 90/10 comes from a different feedstock and blowing profile, producing a tighter asphaltene network at a lower softening point. The result is a binder with the hardness of a very hard grade and the melting behaviour of a mid-range one, which is exactly what buried pipe coating needs.
Can oxidized bitumen 90/10 be used for roofing membrane?
No. At 10 dmm the sheet cracks at the fold and fails at the lap. Membrane coating needs 90/40, 85/25 or 105/35 depending on climate. 90/10 can be used for the primer or base coat beneath the membrane, which is a different function.
Should I choose 90/10 or 115/15 for pipe coating?
For pipeline buried in ground that stays below about 35 °C, 90/10 delivers the hardness the coating needs without paying for softening point that will never be used, and it works at a lower application temperature. Where the line runs above ground, crosses hot desert, or the specification names a higher service temperature, 115/15 gives the necessary margin.
What temperature do I melt oxidized bitumen 90/10 at?
Melt at 175 to 200 °C, pump at 185 to 205 °C and apply at 190 to 215 °C, using indirect heating. Do not exceed 225 °C. This is 10 to 25 °C lower than 115/15 or 150/5 require, which is a real operational advantage on a continuously running coating line.
What is the difference between 90/10, 90/15 and 90/40?
They share the same softening point band of 85 to 95 °C but the penetration runs from 5 to 15 dmm, 10 to 20, and 35 to 45 respectively — a factor of four across the three. 90/10 is the hardest and suits pipe coating and static industrial compounds; 90/15 is firm and suits adhesive and sealing work; 90/40 is flexible and suits membrane. Ordering by softening point alone across these three is a common and expensive mistake.
Is oxidized bitumen 90/10 the same as blown asphalt 90/10?
Yes. Oxidized bitumen, blown bitumen and blown asphalt all describe the same product — penetration grade bitumen air-blown at high temperature to raise the softening point and reduce the penetration. The naming varies by region rather than by product.
What is the shelf life of oxidized bitumen 90/10?
Two to three years in sealed packing kept dry, on pallets and out of direct sun. Chemical ageing is slow because the material is already blown. 90/10 is among the easiest blown grades to store because at 10 dmm the blocks stay rigid and stack fusion is rarely a problem even in tropical container temperatures.
What is the HS code for oxidized bitumen?
HS 2713.20, petroleum bitumen, which covers all oxidized and penetration grades. National tariffs add further digits, so confirm the full code with your customs broker. Gilsonite and other natural bitumen fall under a different heading.
What is the minimum order quantity?
One full 20′ container, roughly 22 to 25 MT depending on packing. Mixed grades in one shipment are accepted provided each grade reaches one full container. Loading is from Jebel Ali Port in Dubai or Iskenderun Port in Turkey, on FOB, CFR or CIF terms.
Can you supply against a tighter specification?
Yes, and for this grade it is worth asking. The 5 to 15 dmm penetration window is wide relative to the value — a batch at 14 dmm is nearly three times softer than one at 5. Where creep resistance is critical, contract to a narrower band such as 8 to 12 dmm. Say so at the enquiry stage, since it affects which production batch is allocated.
Related grades and technical pages
Adjacent grades: oxidized bitumen 90/15 and 105/15 for slightly softer hard work, 115/15 and 150/5 where higher service temperature is required, and 90/40 where the same softening point is needed in a flexible binder. The complete list is on the oxidized bitumen grades page.
Where a compound needs additional hardness, gloss or a higher softening point than blown bitumen alone can deliver, gilsonite is frequently blended in — see gilsonite specification, gilsonite in paint and gilsonite in asphalt. For the difference between air-blown and naturally occurring hard bitumen, see natural bitumen.
Request a quotation for oxidized bitumen 90/10
Send us the quantity, packing, discharge port and the specification your contract names. Tell us the service temperature the compound will see and we will confirm whether 90/10 is right or whether 105/15 or 115/15 suits better. Batch certificate of analysis with every shipment, third-party inspection accepted at loading.
Dubai: No. 2305, Burlington Tower, Business Bay — +971 4 566 4998
Ankara: Karşıyaka District, 749 Street No. 30, Gölbaşı 06830 — +90 312 544 5481
Isfahan: Second Floor, Navab Complex, Navab Safavi St
