Industrial bitumen is a commercial category rather than a single specification. It is defined by what it is not — it is every bitumen that is not going into a pavement.
The road market buys binder by penetration or viscosity band and consumes it in tonnes per kilometre. The industrial market buys by the property it needs at the point of use: a softening point high enough to survive a switchgear cabinet, a penetration low enough to resist a stone bearing on a buried pipe, a filler loading that makes a mastic non-sag on a vertical wall, a break rate that lets an emulsion soak into loose sand. The tonnages are far smaller, the specifications are far more varied, and the buyer is usually a compounder or a fabricator rather than a contractor.
Three physical forms sit inside the category, and confusing them is the most common source of a wrong order:
There is no single global specification for industrial bitumen. What exists is a set of framework standards and a set of application specifications:
Industrial grades are written softening point first, penetration second. 115/15 means a softening point of about 115 °C and a penetration of about 15 dmm — it is not a penetration band. Paving grades use the opposite convention, where both figures are penetration limits and the pair ascends: 60/70, 80/100, 120/150. If the first number is larger than the second, you are looking at an industrial grade. Judging by the first number alone does not work — 85/100 is a soft paving binder and 85/25 is a hard blown grade, and a purchase order that carries only the digits will not tell a warehouse which of the two was meant. Where a drawing or a specification is ambiguous, get the seller to state in writing which property the first figure represents before anything is nominated.
Polymer modified binders for heavy-duty paving, performance-graded binders and viscosity-graded binders are road products even though they are engineered materials. Air-rectified or semi-blown bitumen belongs with them: it has seen a blowing step, but only enough to bring a paving binder into its specification band, and it is sold, tested and used as a paving grade — so material offered as semi-blown against an industrial enquiry is answering a different question and should be sent back. The traffic runs the other way too, and the reasons a fully blown grade cannot be put through an asphalt plant are set out on the oxidized bitumen page.
This is the single idea that makes the rest of the page predictable. A pavement and an industrial part ask the binder for opposite things.
A bituminous pavement is a structural layer. It carries repeated wheel loads through a daily temperature swing that can exceed 40 °C, and the binder is asked to be genuinely visco-elastic: stiff enough at 60 °C to resist rutting, relaxed enough near 0 °C to avoid thermal cracking, and able to absorb and dissipate strain energy under every axle without accumulating damage. That is why a paving specification carries a ductility minimum of 100 cm, a retained-penetration limit after the thin film oven test, and — in the performance grading system — a high-temperature and a low-temperature criterion measured on separate instruments. The binder has to move, recover and keep moving, millions of times.
An industrial application usually asks for none of that. A filled cable box, a sealed battery lid, a coated pipe under backfill, a sound deadening pad bonded to a floor pan, a mastic on a vertical wall — these carry little or no repeated load and are not required to relax and recover. What they are required to do is stay exactly where they were placed, and stay sealed, at whatever temperature the part actually reaches in service. Flow is the failure mode. Creep is the failure mode. Sag, slump, bleed and drain-out are the failure modes.
Run the arithmetic on a paving grade and the problem is immediate. Bitumen 60/70 has a ring-and-ball softening point of 49–56 °C. A dark flat roof in a hot climate reaches around 75 °C on a summer afternoon. A vehicle floor pan above the exhaust tunnel runs hotter than that. A filled cable box sits at the sheath temperature of a loaded conductor. A stockpiled coated pipe in direct sun in the Gulf will exceed 60 °C on the upper surface before it is ever buried. In every one of those cases the paving binder is above its softening point in normal service, and a material above its softening point does not stay where it was placed.
Air blowing converts a large part of the maltene fraction into asphaltenes, moving the colloidal structure from a sol toward a gel. Two consequences matter commercially:
For a compounder this is also a free incoming check, because the index is derived from two figures that already appear on every Certificate of Analysis. Run it on the batch before the material goes into a recipe. A consignment sold as a blown grade whose measured pair returns an index down in the paving range has not been given the structure the formulation depends on, and the consequence shows up as drift in the finished part weeks later, long after the drum has been emptied and the claim window has closed.
Sound deadening is the exception, and understanding it stops a formulator reaching reflexively for the hardest grade in the catalogue. Vibration damping works by converting mechanical strain energy into heat, and that conversion peaks close to the material's glass transition — the same region where a paving binder's visco-elastic loss is largest. A damping compound is therefore formulated so its loss peak sits inside the service temperature window of the panel it is bonded to. Too hard and the material stores energy elastically instead of dissipating it, and the damping disappears. Too soft and the pad sags off a vertical panel in a paint oven or in a hot climate. The result is a deliberately intermediate choice — a mid-range blown grade at heavy filler loading, tuned with rubber or a resin — rather than the hardest material available. Joint sealants sit in a similar middle ground for a different reason: they need movement capability, which no amount of blowing provides.
This table is the spine of the page. For each non-paving application it names the grade family that suits it, why that family and not another, and the property that actually decides whether the finished part performs. Everything below expands on these rows.
| Application | Grade family that suits it | Why that family | Property that governs performance |
|---|---|---|---|
| Pipeline coating enamel | Hard blown base — 90/15 or 115/15 — plus 25–35 wt % inert mineral filler | The coating must resist indentation from backfill stone at line temperature and stay bonded to steel while the pipe is cathodically protected | Measured on the finished enamel, not the base: penetration at 25 °C max 10 dmm (ASTM D5); softening point 95–110 °C (ASTM D36); cathodic disbondment (ASTM G8 / G42) |
| Cable jointing, cable box and pot-head filling | Oxidized 115/15 and 150/5, usually mineral filled | It must set void-free, exclude moisture for the life of the joint, and not creep out of a vertical enclosure at conductor temperature | Softening point (ASTM D36); dielectric breakdown voltage (ASTM D149); volume resistivity (ASTM D257); water content (ASTM D95) |
| Battery sealing compound | Oxidized 105/35 to 115/15, mineral filled | The seal must hold to case and lid through charge heating and cold starts, and survive contact with sulphuric acid | Softening point (ASTM D36); adhesion and cracking after thermal cycling; acid resistance by immersion |
| Sound deadening and vibration damping pads | Oxidized 85/25 to 105/35 at high filler loading, commonly rubber or EVA modified | The one industrial use that wants visco-elastic loss — the compound is tuned so its damping peak sits inside the panel's service temperature range | Composite loss factor on an Oberst bar (ASTM E756 / SAE J1637) |
| Roofing, flashing and membrane adhesives | Oxidized 85/25 or 95/25, fibre and filler loaded, hot applied or solvent cut | It must hold on a vertical surface at roof temperature without slumping and still be workable in cold weather | Consistency and sag resistance (ASTM D4586 asbestos-free asphalt roof cement; ASTM D3019 lap cement) |
| Hot-poured joint and crack sealant | Blown base modified with polymer or crumb rubber — grade alone will not reach the class | It must bond to the joint face at winter temperature without failing, and not flow out of the joint at summer temperature | ASTM D6690 Types I to IV, tested to ASTM D5329 (cone penetration, flow, bond, resilience) |
| Preformed expansion joint filler board | Blown grade as the binder for a fibre, cork or cellulose board | It must compress as the joint closes and recover as it opens, without extruding above the slab in summer | ASTM D994 (bituminous type); ASTM D1751 (non-extruding and resilient bituminous types) |
| Bituminous protective paint | Blown or hard grade dissolved in a hydrocarbon solvent | Dry film build per coat, and a film that stays intact on steel or concrete through wet–dry and heat cycling | Non-volatile (solids) content; drying time; solvent flash point by Tag open cup (ASTM D1310); IS 158 for brushing bituminous black paint |
| Primer under enamel, membrane or damp-proofing | Soft blown or paving-grade base in a light solvent | It must wet the blast profile or the concrete pore structure and dry tack-free before the hot layer is applied | ASTM D41 asphalt primer; drying time treated as a hold point, not a target |
| Damp-proofing and structural waterproofing | Oxidized 85/25 and 95/25, hot applied over primer | It must not sag on a vertical or sloped surface at the temperature the structure reaches, and must stay continuous over movement | ASTM D449 Types I to III classify the asphalt by softening point; softening point (ASTM D36) |
| Sand dune fixation, soil mulching and dust control | Slow-setting bitumen emulsion, diluted with water — not a solid grade at all | The emulsion must break slowly enough to penetrate loose sand and bind a thin crust, without sealing the surface against water and air | Emulsion classification (ASTM D977 anionic / ASTM D2397 cationic); residue by evaporation; dilution and rate set for the sand grading |
| Tree wound dressing, grafting and horticultural sealing | Petroleum bitumen solution or emulsion — never a coal tar product | It must seal a cut surface without harming living tissue; coal tar carries phenolic constituents that are phytotoxic | Petroleum base confirmed on the Safety Data Sheet; solvent content checked before use near live cambium |
These three share a grade family — the hardest material in the range, 115/15 and 150/5, usually mineral filled — and they share a requirement: absolute dimensional stability at a service temperature well above ambient.
Hot-applied bitumen enamel is the oldest external coating system still in commercial use for buried and submerged steel pipe, and it is bought as a material but performs as a system. The layer build is blast-cleaned steel, bituminous primer, enamel flood coat, inner glass-fibre wrap embedded while the enamel is still molten, enamel over-coat, and outer wrap. That architecture is set out in AWWA C203 — remembering that C203 itself specifies coal-tar enamel as the material — while the material standard for petroleum bitumen enamel is BS EN 10300, and Indian projects work to IS 10221 as the code of practice for coating and wrapping underground mild steel pipelines.
The base is a hard blown grade — 90/15 and 115/15 are both used — blended with 25–35 wt % inert mineral filler. The filler is not a diluent. It adds body, raises the softening point of the compound and suppresses flow, so the base is chosen so that the finished enamel lands where the coating standard puts it: typically a softening point of 95–110 °C and a penetration at 25 °C of no more than 10 dmm. Those acceptance figures belong to the enamel, not to the base drum, and quoting one against the other is how enamel enquiries go wrong. Two properties govern the outcome:
The glass-fibre wrap is the structural element and is not optional. It carries impact and handling load, restrains cold flow on a pipe that runs warm, and stops a local impact from propagating into a large disbonded area. An unreinforced hot bitumen film of the same thickness does not come close to the same falling-weight result under ASTM G14. Filler is not optional either, and it must be kept in suspension: filler settles in an unstirred kettle, and enamel drawn from the bottom is filler-rich while the top is filler-lean, which shows up later as inconsistent thickness and inconsistent indentation resistance along a single pipe run.
One recurring false alarm is worth flagging. Solubility in trichloroethylene at minimum 99 % applies to the bitumen phase before filler is blended in. A finished filled enamel will never dissolve completely, because the filler is inert by design, and a result in the region of 65–75 % on the packed compound is normal rather than evidence of adulteration. Full detail on the enamel specification, the applied-system tests and the withdrawn ASTM methods still circulating in old project documents is on the bitumen enamel grade page.
Alongside factory-applied enamel, the same grade family supports the cold end of pipeline corrosion protection: bituminous mastics and petrolatum-style tapes for field joints and cutbacks, bituminous paint for above-ground steel, and bituminous coatings for buried tanks and structural steelwork. Field joints and repairs need a compatible system agreed before the pipe leaves the yard, not improvised in the trench.
Bituminous filling compounds fill cable joint boxes, sealing ends, pot heads and terminal boxes, and serve as potting media for capacitors and small transformers. The grades are the hardest in the range — 115/15 and 150/5 — usually mineral filled to reduce shrinkage and improve thermal behaviour. The lineage of most specifications in this field runs back to BS 1858, the British specification for bitumen-based filling compounds for electrical purposes, which is now largely historic but is still the document that project requirements descend from.
Four properties decide whether the compound works, and only one of them is electrical:
Bituminous sealing compound seals the joint between the case and the lid of a lead-acid battery, and seals around the terminal pillars. The grade family is 105/35 to 115/15, mineral filled, sometimes with a small reclaimed-rubber content to add flexibility. What the compound must survive is a demanding combination:
It is worth being straightforward about the size of this market. Modern automotive SLI batteries are heat-sealed polypropylene and use no bituminous compound at all. The demand that remains is in traction and tubular batteries, stationary and standby cells, hard-rubber-cased industrial batteries and repair and refurbishment work — which is concentrated in South Asia, the Middle East and Africa rather than in Europe or North America. It is a narrow and contracting application rather than a general one, so name the battery type on the enquiry: a compound specified for a tubular traction cell is not the same material as one for a hard-rubber stationary cell, and the softening point and the flexibility are set from that.
This second family uses the mid-range blown grades — 85/25 through 105/35 — heavily loaded with filler and usually modified. Here the base grade is one input among several, and the formulation carries most of the performance.
Bituminous damping material goes onto vehicle floor pans, wheel arches, door panels and bulkheads, onto the side panels of washing machines and dishwashers, onto ducting, and into rail and marine interiors. Commercially it takes three forms: extruded or calendered sheet cut to shape and bonded, melt-on pads that are laid on the panel and fused during the paint bake, and heavy bituminous board for floating floors and machinery bases. Sprayable liquid-applied damping is usually a water-based acrylic rather than a bitumen product, which is a boundary worth knowing before an enquiry goes out.
The composition is a mid-range blown grade with a heavy mineral filler loading — frequently in the region of 50–70 wt % — plus reclaimed rubber, EVA or a hydrocarbon resin. Filler adds mass, which matters because a damping treatment works partly by adding areal density to a thin panel, and it reduces cost. But the property that is actually specified is the composite loss factor, measured by bonding the material to a steel bar and exciting it — the Oberst beam arrangement of ASTM E756, or SAE J1637 for the automotive version of the same measurement.
As set out earlier, the loss factor peaks near the glass transition of the compound, so formulation is about placing that peak inside the panel's service window rather than maximising hardness. A floor pan in a hot climate spends most of its life between roughly ambient and 60 °C or higher over the exhaust tunnel; an appliance panel is far cooler and far more constant. The same specification will not serve both. When ordering base bitumen for a damping compound, state the service temperature band and whether the pad is applied cold or fused in an oven — the oven temperature sets a hard limit on how soft the base can be.
This family covers roofing and flashing cement, lap cement for roll roofing, membrane and tile adhesives, marine and deck compounds, and general construction mastics. It splits cleanly in two:
The base is normally 85/25 or 95/25. The governing property is consistency and sag resistance: a flashing cement has to hold a bead on a vertical surface at the 75 °C a dark roof reaches in summer sun, without slumping, and still be trowelable on a cold morning. That range is achieved by fibre and filler loading and by the solvent balance, not by reaching for a harder bitumen — a harder base makes the compound stiff to apply and brittle in service without improving sag resistance as much as filler does. ASTM D4586 covers asbestos-free asphalt roof cement and ASTM D3019 covers lap cement; both specify the consistency and sag behaviour rather than the base grade, which is the right way round.
Two entirely different products are routinely conflated in enquiries, and the distinction is worth stating plainly:
The important commercial point about sealant is that the grade will not get you there. A D6690 Type III or Type IV sealant must survive repeated extension at temperatures well below zero without losing bond, and no amount of air blowing produces that. The classes are reached with polymer or crumb rubber in the formulation, on a mid-range blown base. If an enquiry asks for an oxidized grade that meets ASTM D6690, the honest answer is that the standard applies to the finished sealant and not to the base bitumen, and the base is one component of a formulation the compounder owns. What a base supplier can sensibly be asked for is a consistent softening point and penetration pair, batch to batch, so the compounder's recipe does not drift underneath them.
The last two families do not arrive as solid blocks at all. One is bitumen in solvent, the other is bitumen in water, and in both the carrier governs performance as much as the bitumen does.
A bituminous paint is a blown or hard grade dissolved in a hydrocarbon solvent — chemically a cutback, whatever the label calls it. It is brushed, rolled or sprayed onto structural steelwork, tanks, gates and penstocks, vehicle underbodies, buried metalwork and concrete and masonry needing a damp-proof coating. In India the reference is IS 158, ready mixed paint, brushing, bituminous, black, lead-free, acid, alkali and heat resisting. It is a protective paint for steelwork and it is not a pipeline enamel, despite frequently being named alongside enamel work in project documents.
Three composition figures decide what the product does:
Primers are the same chemistry aimed at a narrower job. ASTM D41 covers asphalt primer for roofing, dampproofing and waterproofing. A primer's function is to wet the substrate — the angular anchor profile on blast-cleaned steel, or the pore structure of concrete — displace the last trace of surface moisture, and give the hot layer above it something chemically compatible to bond to. Its stated drying time is a hold point, not a target. Flooding hot enamel or hot membrane bitumen at 200–230 °C over a primer that has not finished releasing its solvent is a fire risk rather than a cosmetic defect, because the vapour is driven off directly into and above a surface well over 200 °C. A film that is still tacky, or that can still be smelled, has not finished drying — and no production schedule alters that.
Two further practical points. Aluminium-pigmented bituminous coatings, covered by ASTM D2824, are used where a reflective finish is needed on roofs and tanks to reduce solar gain, and they are one of the few ways to give a bituminous film reasonable appearance retention outdoors. And bitumen bleeds through most conventional topcoats, so if the asset will later be repainted in a different chemistry, a bituminous coating is a decision that is expensive to reverse.
Agricultural bitumen work is almost entirely emulsion work, for a simple reason: the material is being applied to living soil and living plants, usually in thin films, with no heating equipment anywhere near. A bitumen emulsion is bitumen dispersed in water with an emulsifier, and it is applied cold and diluted.
One boundary to respect: bituminous coatings should not be used in contact with stored feed or produce, and should not be applied inside tanks holding drinking water for people or livestock unless the specific product is certified for that contact. If an agricultural enquiry involves potable or stock water, say so at the enquiry stage rather than after the material arrives.
Industrial users remelt solid bitumen in far smaller vessels than a road contractor uses, often indoors, and often close to solvents. Two numbers set the ceiling for every operation in this table: the flash point on the Certificate of Analysis, less a real working margin, and the finished blowing temperature stated by the producer. Heating a blown grade above the temperature at which it was made begins to undo the blowing reaction — softening point falls, fume rises sharply and the material darkens and thins.
| Material | Typical melting or kettle range | Absolute ceiling | The number that actually controls it |
|---|---|---|---|
| Oxidized 75/25 to 95/25 — membranes, mastics, adhesives | 180–200 °C | 230 °C | Finished blowing temperature on the producer's data sheet. Where the job specifies an equiviscous temperature — the temperature at which the material reaches 125 centistokes for mop application or 75 centistokes for a mechanical spreader, centistokes and not centipoise — apply within about 14 °C (25 °F) of it |
| Oxidized 105/35 — flexible sealants and joint compounds | 185–205 °C | 230 °C | Hold time. Oxidation continues in an open kettle, so compound held hot for days keeps hardening and drifts out of its sealant class |
| Oxidized 115/15 and 150/5 — electrical, potting, enamel base | 200–230 °C | 230 °C | Rate of heat input. Hard grades need heat applied gradually and evenly — never fire a dry vessel wall or energise an uncovered coil |
| Filled pipeline enamel, remelt at the coating yard | 200–230 °C | 230 °C | Agitation. Filler settles, and an unstirred kettle delivers filler-rich and filler-lean material from the same batch |
| Electrical filling compound at the pour | Producer's stated pouring window | Insulation limit inside the enclosure | Bracketed at both ends — hot enough to flow into the conductor bundle, cool enough not to damage paper or polymer insulation already in the box |
| Bituminous paint and primer (solvent cut) | Do not heat | Not applicable | The solvent flash point — a Tag open cup figure (ASTM D1310) for a cut-back product, not the Cleveland figure quoted for solid bitumen — which in many primers is below ambient in a hot climate. Store away from the kettle and keep a separate Safety Data Sheet |
| Bitumen emulsion for agricultural and soil work | Ambient storage, roughly 10–60 °C | Not applicable | Emulsions break irreversibly on freezing and on boiling. Protect from frost, keep out of direct sun, and do not pump through a hot line |
Industrial buyers pack differently from road buyers, and for a good reason. A road contractor decants a drum into a bulk tank once and has done with it. A compounder charges a kettle or a mixer by hand, several times a shift, against a recipe weight — so the unit that matters is the one an operator can lift and dose without decanting equipment. That is why blocks, cartons and bags dominate this market and drums are the exception rather than the default.
| Packing | Net weight per unit | Typical units per 20' FCL | Typical net cargo per 20' FCL | Best suited to |
|---|---|---|---|---|
| Block in kraft-lined carton | 25 kg | palletised — count set by the pallet pattern, roughly 720–800 cartons | 18–20 MT | Kettle and mixer charging by hand — the block goes in whole, with no decanting and no drum disposal |
| Block in multi-wall kraft bag | 25 kg | palletised — count set by the pallet pattern, roughly 720–800 bags | 18–20 MT | Compounders taking a steady feed; cheaper than cartons, with less stack strength |
| Meltable poly bag | 1 MT | 20 bags | 20 MT | Buyers with a melting unit and a hoist — the film enters the melt with the product, so the specification has to permit it |
| Jumbo bag with release liner | 1 MT | 20 bags | 20 MT | Yards with a crane or hoist over the kettle; liner stripped off before charging |
| New steel drum | 150 kg | 80 drums | 12 MT | Buyers without covered storage — sealed, stackable and weatherproof |
| New steel drum | 180 kg | 80 drums | 14.4 MT | Lower packing cost per tonne than 150 kg drums, at the same container count |
| New steel drum | 185 kg | 80 drums | 14.8 MT | The heaviest common drum fill; confirm destination handling equipment before ordering |
| Bitutainer / tank container | 20–25 MT | 1 unit | 20–25 MT | Only where the buyer has heating capability and a dedicated receiving tank |
It is the commercial category covering every bitumen that is not going into a pavement. In practice it means the oxidized or blown grades from 75/25 to 150/5, the filled compounds built on them such as pipeline enamel, sound deadening sheet, roof cement and battery compound, and the liquid forms — solvent-cut paints and primers, and emulsions used in soil and agricultural work. It is framed by EN 13304 and EN 13305 in Europe, by the withdrawn BS 3690-2 R-grade designations still found on older drawings, and by application standards such as ASTM D312 for roofing and ASTM D449 for dampproofing and waterproofing.
They are asked for opposite things. A pavement binder must be visco-elastic: stiff enough at 60 °C to resist rutting and relaxed enough near 0 °C to avoid cracking, dissipating strain energy under millions of wheel loads. An industrial part usually carries no repeated load and must simply stay where it was placed and stay sealed at the temperature the part reaches. So industrial work wants a high softening point and low temperature susceptibility, which is what air blowing produces. The penetration index runs about −1 to +1 for paving bitumen and about +2 to +6 for the blown grades.
Almost never, and the reason is arithmetic rather than opinion. Bitumen 60/70 has a softening point of 49–56 °C. A dark flat roof reaches around 75 °C in summer sun, a vehicle floor pan above the exhaust tunnel runs hotter, and a filled cable box sits at conductor temperature. In each case the paving binder is above its softening point in normal service, so it creeps, sags, bleeds or drains out of the joint. The one legitimate use of a paving grade in this field is as a soft base for primers and some cold-applied cutback products, where the material is applied thin and is not load-bearing.
The base is a hard blown grade — 90/15 and 115/15 are both used — blended with 25 to 35 wt % inert mineral filler. Filler raises the softening point of the compound, so the base is selected so that the finished enamel lands in the band the coating standard sets: softening point 95–110 °C and penetration at 25 °C of no more than 10 dmm, both measured on the enamel rather than on the base. What governs performance is indentation resistance at line temperature, tested by the blunt-rod method of ASTM G17, and cathodic disbondment to ASTM G8 or ASTM G42. The glass-fibre wrap embedded in the molten enamel is the structural element of the system and is not optional — it carries impact and handling load and restrains cold flow.
The hardest grades in the range, 115/15 and 150/5, usually mineral filled. The controlling property is a softening point comfortably above the temperature the enclosure reaches, because a compound that creeps out of a vertical box has failed regardless of its electrical numbers. Beyond that, the compound must set void-free — bitumen contracts on cooling, so deep boxes are poured in stages and topped up — must be dry when poured, and must meet dielectric breakdown voltage to ASTM D149 and volume resistivity to ASTM D257. Never pour into a wet enclosure.
Most industrial buyers take 25 kg blocks in kraft-lined cartons or multi-wall kraft bags, palletised, which load roughly 18 to 20 MT into a 20-foot container. One-tonne jumbo or meltable poly bags load 20 bags and 20 MT. New steel drums load 80 drums per 20-foot container in every common size — about 12 MT at 150 kg net, 14.4 MT at 180 kg and 14.8 MT at 185 kg — and a bitutainer or tank container carries 20 to 25 MT. Cartons and bags usually win on total handled cost for a compounder because they remove decanting, tare reconciliation and steel disposal from the workshop.
Petroleum bitumen is used routinely in agriculture — slow-setting emulsions for sand dune fixation, soil mulching and dust control, and bituminous linings for irrigation canals and ponds. The rule that matters is to use a petroleum bitumen product and never a coal tar one, because coal tar carries phenolic constituents that are phytotoxic and will damage living tissue at a cut face. Check the solvent as well as the base on any product going near live cambium. Bituminous coatings should not contact stored feed or produce, and should not be applied inside tanks holding drinking water for people or livestock unless the specific product is certified for that contact.
Unfilled petroleum bitumen, including the straight oxidized grades, is classified under HS heading 2713.20. Once mineral filler is blended in, the product is normally a bituminous mixture under heading 2715.00 — which covers pipeline enamel, filled mastics and similar compounds. The distinction can change the duty rate at destination, so confirm the full national subheading with your customs broker before the shipping documents are issued rather than after the cargo has moved.
One naturally occurring material sits alongside the refined industrial grades and is often confused with them.
Send the application, the service temperature the part will see, the standard the finished product is tested against, the quantity and packing you want, and the destination port with your Incoterm. Those five items are enough to select the grade and check the offer against your requirement before it is priced. If you are compounding rather than using the material directly, say so — the questions that matter are batch-to-batch consistency and packing format rather than the grade name alone.