Twelve oxidized bitumen grades exist because twelve different problems need solving. Most buyers arrive knowing a grade name from a specification document and want to confirm it is right. Some arrive knowing only the application. This page works both ways: it sets out every grade we supply with its specification, and it provides the selection logic to get from what your compound has to do in service to which of the twelve you should order.
RAHA Gilsonite supplies the full oxidized range against ASTM D312, BS EN 13304:2009, BS 3690, DIN 1995 or a buyer’s own specification, with a batch certificate of analysis issued before loading. Every grade below has its own page with the full specification, melting temperatures and application detail.
What oxidized bitumen is
Oxidized bitumen — also called blown bitumen or blown asphalt — is produced by blowing hot compressed air through penetration grade bitumen at around 240 to 270 °C. Oxygen reacts with the maltene fraction and converts it toward asphaltenes. The binder becomes harder, the softening point climbs and the penetration falls.
The change is chemical and irreversible. It converts the colloidal structure from a sol type, where asphaltenes are dispersed, to a gel type with a continuous asphaltene network. That structural change is what gives oxidized grades their defining property: low temperature susceptibility, meaning the consistency changes far less across the service temperature range than a penetration grade of equivalent stiffness.
The trade-off is fatigue resistance. Oxidized bitumen holds its shape under heat but fractures rather than recovering under repeated flexing, which is why it belongs on roofs, around pipes and inside industrial compounds — and never in a road. For the full comparison see natural bitumen and the penetration grade family.
Reading a grade designation
The name reads softening point over penetration. In 105/35, the 105 is the ring-and-ball softening point in degrees Celsius and the 35 is the penetration at 25 °C in tenths of a millimetre. Under BS EN 13304:2009 both figures are expressed as multiples of 5.
Two numbers are necessary because blowing breaks the predictable relationship between them. A penetration grade needs only one figure — a 60/70 binder lands at a softening point of 49 to 56 °C almost regardless of where it was refined. Blowing raises the softening point faster than it lowers the penetration, and how far it does each depends on feedstock and blowing conditions. Two oxidized grades can share a softening point and differ completely in hardness.
The single most common ordering error. Specifying by softening point alone. 90/40, 90/15 and 90/10 all sit in the same 85 to 95 °C band, but the penetration runs from 40 dmm down to 10 — a factor of four. One makes membrane, one makes adhesives, one coats pipe. They are not interchangeable.
All twelve grades at a glance
| Grade | Softening point | Penetration | Class | Principal use |
|---|---|---|---|---|
| 150/5 | 145–155 °C | 0–10 dmm | Hardest | Electrical compounds, battery sealing, pipe enamel, rubber compounding |
| 115/15 | 110–120 °C | 10–20 dmm | Hard | Waterproofing, adhesives, sealing compounds, pipe coating in hot climates |
| 105/35 | 100–110 °C | 30–40 dmm | Medium | Roofing membrane for hot climates. Heat resistance with retained flexibility |
| 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 for warm-temperate markets |
| 90/40 | 85–95 °C | 35–45 dmm | Softer | Roofing felt and membrane for temperate and cool climates |
| 90/15 | 85–95 °C | 10–20 dmm | Medium | Bituminous adhesives, sealing compounds, mastics |
| 90/10 | 85–95 °C | 5–15 dmm | Hard | Pipe coating enamel, cable filling, tank lining |
| 85/40 | 80–90 °C | 35–45 dmm | Softer | Cold-climate membrane and winter installation |
| 85/25 | 80–90 °C | 20–30 dmm | Medium | The volume roofing grade worldwide |
| 75/35 | 70–80 °C | 30–40 dmm | Softest | Cable impregnation, bituminous paint, sound damping |
| 75/25 | 70–80 °C | 20–30 dmm | Softest | Below-grade waterproofing, damp proof course, jointing |
Choosing by application
If you know what the compound has to do but not which grade to name, start here.
| Application | First choice | Alternative | Why |
|---|---|---|---|
| Roofing membrane, hot climate | 105/35 | 115/15 for extreme heat | Holds at 80 °C+ roof surface without losing fold tolerance |
| Roofing membrane, temperate | 85/25 | 95/25 if summers are hot | The global volume grade. Adequate and cheapest where climate allows |
| Roofing membrane, cold climate | 85/40 | 90/40 | Survives winter unrolling and folding without cracking |
| Damp proof course sheet | 90/40 | 85/40, 75/25 | Rolled tight and unwound cold. High penetration essential |
| Pipe coating enamel, buried | 90/10 | 105/15 | Ground stays cool. Hardness and creep resistance matter, not heat margin |
| Pipe coating, hot or exposed | 115/15 | 150/5 | Above-ground sections need genuine heat resistance |
| Bituminous adhesives | 90/15 | 105/15 for hot service | Holds under load, tolerates slight substrate movement |
| Sealing compounds, static joint | 105/15 | 90/15, 90/10 | Creep resistance governs; no flexibility needed |
| Expansion joints that move | 105/35 | 90/40, 85/40 | The joint opens most when the binder is least flexible |
| Below-grade waterproofing | 75/25 | 95/25, 105/35 | Ground temperature is stable. The economic choice |
| Electrical cable impregnation | 75/35 | 75/25 | Must penetrate between strands. Flow beats hardness |
| Battery sealing, potting compounds | 150/5 | 115/15 | Rigidity at operating temperature, no cold flow |
| Bituminous paint and coatings | 75/35 | 75/25 | Must brush to a thin even film without dragging |
| Sound damping pads | 75/35 | 85/40, 90/40 | Bonded to a vibrating panel. Brittle compounds delaminate |
| Rubber and tyre compounding | 150/5 | 115/15 | A hard, high-melting bituminous phase is wanted |
| Industrial mastic and flooring | 105/15 | 90/10, 115/15 | Sustained static load. Creep resistance governs |
Choosing by climate
For roofing and any exposed application, climate is the deciding variable and it is the one most often skipped. A dark surface in direct sun runs 30 to 35 °C above the air temperature. Work backwards from the softening point and you get a usable ambient limit.
| Peak ambient | Approx. surface temperature | Minimum grade | Typical markets |
|---|---|---|---|
| Below 30 °C | 60–65 °C | 75/25 or 85/25 | Northern Europe, highland regions, cool maritime |
| 30–42 °C | 65–77 °C | 85/25 | Central Europe, temperate Asia, highland Africa |
| 42–48 °C | 77–83 °C | 95/25 or 105/35 | Mediterranean, southern China, Latin America, coastal East Africa |
| Above 48 °C | Above 83 °C | 105/35 or 115/15 | Gulf, North Africa, South Asia, equatorial belt |
| Winter below 0 °C with seasonal installation | — | 85/40 or 90/40 | Russia, Baltics, Scandinavia, northern China, Mongolia |
Where both extremes apply — hot summers and genuine winters — no single unmodified grade covers the range comfortably. 105/35 is usually the best compromise because it carries a high softening point with unusually good retained penetration. Tell us both temperatures and we will say which fits.
The grades most often confused
Three pairs account for most mis-specification in this range.
The 90 series: 90/10, 90/15 and 90/40
All three sit in the 85 to 95 °C softening band. The penetration runs from 5 to 45 dmm across them — nearly a factor of nine between the extremes. 90/10 coats pipe, 90/15 makes adhesives, 90/40 makes membrane. Ordering by the first number alone across these three is the single most expensive mistake in the range.
Same penetration, different heat: 85/25 and 95/25
85/25 and 95/25 behave identically at ambient temperature — both 20 to 30 dmm. The difference is roughly 10 °C of softening point, and it decides whether a membrane survives a Mediterranean summer. The price difference is small against the cost of a failed roof.
Same softening point, different flexibility: 105/15 and 105/35
105/15 and 105/35 both hold 100 to 110 °C. 105/35 carries roughly double the penetration and folds without cracking; 105/15 is rigid. Substituting 105/15 into a membrane line produces sheets that crack at the lap.
Melting and application temperatures
Each grade has its own window and its own ceiling. A production line configured for one grade and switched to another without adjusting the settings will run too hot or too cold.
| Grade | Melting | Application | Maximum |
|---|---|---|---|
| 150/5 | 220–245 °C | 230–250 °C | 260 °C |
| 115/15 | 180–205 °C | 200–225 °C | 230 °C |
| 105/35 | 170–195 °C | 190–215 °C | 230 °C |
| 105/15 | 180–205 °C | 200–225 °C | 230 °C |
| 95/25 | 165–190 °C | 185–210 °C | 225 °C |
| 90/40 | 160–185 °C | 180–205 °C | 220 °C |
| 90/15 | 170–195 °C | 185–210 °C | 225 °C |
| 90/10 | 175–200 °C | 190–215 °C | 225 °C |
| 85/40 | 155–180 °C | 175–200 °C | 210 °C |
| 85/25 | 160–185 °C | 170–195 °C | 215 °C |
| 75/35 | 150–175 °C | 165–190 °C | 205 °C |
| 75/25 | 155–180 °C | 170–195 °C | 210 °C |
Overheating undoes what you paid for. Prolonged heat continues the blowing reaction. A batch of 105/35 held above its ceiling across a shift can drop several points of penetration and start behaving like 105/25 — at which point the flexibility you specified has gone. Always use indirect heating, log the tank temperature, and test the finished product rather than only the incoming material.
Safety
Flash points run from 230 °C for the softest grades to over 300 °C for the hardest, so the margin against the working range is thinner at the soft end. Bitumen is a poor conductor of heat, so the melting phase must be controlled to avoid 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.
Applications by industry
-
Roofing and membrane
Coating and impregnation compound for bitumen felt, torch-on membrane, built-up roofing and SBS or APP modified sheet. The largest single use across the range.
-
Waterproofing
Below-grade tanking, basement and foundation protection, bridge deck waterproofing, tunnels, reservoirs and podium decks.
-
Pipe coating
Hot-applied anti-corrosion enamel for buried and above-ground steel pipeline, plus wrapping tape compounds.
-
Electrical and cable
Cable impregnation and filling, joint and termination compounds, transformer and switchgear potting.
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Construction compounds
Adhesives, mastics, expansion joint fillers, crack sealants and industrial flooring compounds.
-
Automotive
Underbody sealants, sound deadening pads, vibration damping and carpet backing compounds.
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Paints and coatings
Black japan, bituminous paints, anti-corrosion primers for steel, marine and offshore structures.
-
Chemical and industrial
Tank lining, bund coating, briquette binders, rubber compounding and process formulations.
Standards and certification
| Standard | Covers |
|---|---|
| ASTM D312 | Standard specification for asphalt used in roofing |
| BS EN 13304:2009 | European framework for specification of oxidised bitumens. Grades expressed in multiples of 5 |
| BS 3690 | British standard for bitumens for building and civil engineering |
| DIN 1995 | German standard for blown bitumen |
| ISIRI 118 | Iranian national standard |
Test methods across all grades follow ASTM D36 for softening point, ASTM D5 for penetration, ASTM D113 for ductility, ASTM D92 for flash point, ASTM D6 for loss on heating and ASTM D2042 for solubility in trichloroethylene. Definitions are maintained by ASTM International.
A note on solubility: older specifications sometimes name carbon disulphide as the test solvent. That solvent has been withdrawn from routine laboratory use on fire-safety grounds, and the current method is ASTM D2042 with trichloroethylene. A certificate quoting CS₂ is worth querying — it usually means the document was copied rather than generated from an actual test.
Packing, storage and shipping
| Packing | Unit weight | Per 20′ container | Notes |
|---|---|---|---|
| Kraft paper bag | 25 kg | Up to 25 MT palletised | Most common. Meltable options available so the bag goes into the melter |
| Carton box | 25 kg | Up to 22 MT | Recommended for soft grades and hot routes. Rigid walls hold block shape |
| New steel drum | 180–190 kg | 80 drums ≈ 15 MT | Safest for tropical transhipment. Requires a drum melter at destination |
| Jumbo bag | 1,000 kg | Up to 22 MT | Lowest packing cost per tonne where handling equipment exists |
Storage: softer grades need more care
All oxidized grades keep two to three years in sealed packing stored dry and out of direct sun. Because the material is already blown, chemical ageing runs slowly and the limit is physical rather than chemical.
How much care a grade needs depends on how close its softening point sits to storage temperature. A container crossing the Red Sea or the equator reaches 60 to 70 °C internally.
| Grade band | Fusion risk on hot routes | Precaution |
|---|---|---|
| 75/25, 75/35, 85/40 | High | Carton or drums. One to two tiers. Unload immediately on arrival |
| 85/25, 90/40, 105/35 | Moderate | Two tiers maximum, under cover, shaded pallets |
| 90/10, 90/15, 95/25, 105/15 | Low | Standard practice. Pallets, under cover, two tiers |
| 115/15, 150/5 | Minimal | Blocks stay rigid. Standard practice |
Full storage rules and retest thresholds are in our bitumen shelf life and storage guide.
Customs classification
All oxidized grades fall 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. Gilsonite and other natural bitumen fall under a different heading, 2714.90, because they are mined rather than refined.
Quality control
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. TDS and MSDS accompany every order.
Reading a certificate properly
Read softening point and penetration together, and check them against the batch rather than the grade range. Specification windows are wide relative to the values: a batch of 105/35 at 109 °C with 31 dmm technically passes but behaves closer to 105/15 in a coating line.
Where your process is sensitive to where the material sits inside its window, contract to a narrower band rather than accepting the full range. Say so at the enquiry stage, since it affects which production batch is allocated.
Frequently asked questions about oxidized bitumen grades
What do the two numbers in an oxidized bitumen grade mean?
The first is the ring-and-ball softening point in degrees Celsius; the second is the penetration at 25 °C in tenths of a millimetre. In 105/35, the softening point is about 105 °C and the penetration about 35 dmm. Under BS EN 13304:2009 both figures are expressed as multiples of 5, and each carries a tolerance, which is why specifications show ranges.
Why do oxidized grades need two numbers when penetration grades need one?
For penetration grades, softening point follows predictably from penetration, so one measurement describes the material. Blowing breaks that relationship: it raises the softening point faster than it lowers the penetration, and how far it does each depends on feedstock and blowing conditions. Two oxidized grades can share a softening point and differ completely in hardness, so both numbers are needed.
Which oxidized bitumen grade should I use for roofing?
It depends on climate. 85/25 for temperate markets, 95/25 where summers are hot, 105/35 for the Gulf, North Africa and South Asia, and 85/40 or 90/40 for cold markets where winter installation matters. Take the peak ambient temperature, add 30 to 35 °C for a dark roof surface, and choose a grade whose softening point sits at least 10 °C above that figure.
Which grade is best for pipe coating?
90/10 for buried pipeline in ground that stays below about 35 °C, because hardness and creep resistance matter there rather than heat margin. 105/15 for general use and 115/15 where the line runs above ground, crosses hot desert or the specification names a higher service temperature.
Can oxidized bitumen be used for road construction?
No. Its gel-type colloidal structure has almost no fatigue resistance, so under traffic loading the binder fractures rather than recovering. The pavement develops transverse and block cracking and ravels, typically within the first or second winter. Road paving needs a penetration, viscosity or performance grade binder.
What is the difference between 90/10, 90/15 and 90/40?
They share the same softening point band of 85 to 95 °C and differ only in penetration — 5 to 15 dmm, 10 to 20 and 35 to 45 respectively. 90/10 coats pipe, 90/15 makes adhesives and sealing compounds, 90/40 makes membrane. Ordering by softening point alone across these three is the most common and expensive error in the range.
Is oxidized bitumen the same as blown bitumen or blown asphalt?
Yes. All three names 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.
How long does oxidized bitumen keep in storage?
Two to three years in sealed packing kept dry and out of direct sun. Chemical ageing is slow because the material is already blown. The practical limit is physical: softer grades such as 75/25, 75/35 and 85/40 can fuse into a single mass under stacking pressure on hot routes, so they need carton or drum packing, limited stacking and prompt unloading.
What happens if oxidized bitumen is overheated?
Prolonged heat continues the blowing reaction, so the softening point drifts upward and the penetration falls. A batch held above its ceiling across a shift can lose several points of penetration and start behaving like a harder grade — removing exactly the flexibility that was specified. Above the maximum the material also cokes and generates heavy fume.
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 2714.90 because they are mined rather than refined.
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 our own specification rather than a grade name?
Yes, and it is usually the better approach. Where a project or customer standard applies rather than ASTM D312 or BS EN 13304, send us the specification rather than the grade name and we will confirm what meets it before you order. If two grades would both work and one costs less, we will say which.
Related pages
Individual grade pages carry the full specification, melting temperatures and application detail: 150/5, 115/15, 105/35, 105/15, 95/25, 90/40, 90/15, 90/10, 85/40, 85/25, 75/35 and 75/25.
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, gilsonite in ink and gilsonite in asphalt. For the difference between air-blown and naturally occurring hard bitumen, see natural bitumen and gilsonite bitumen.
Not sure which grade you need?
Tell us what the compound has to do rather than which grade you think you want — what it is made into, the climate it will serve, whether it moves in service, and the hottest and coldest temperatures it will see. We will name the grade, confirm what the certificate of analysis will state, and tell you honestly if a cheaper grade would do the job.
Dubai: No. 2305, Burlington Tower, Business Bay — +971 4 566 4998
Ankara: Karşıyaka District, 749 Street No. 30, Gölbaşı 06830 — +90 312 544 5481
