XNBR LOW-ACN
Grade
LOW-ACN = low-ACN (≈18–26 % acrylonitrile) low-temperature XNBR
For cold-climate seals and belts needing flexibility to about −40 °C, at the cost of higher oil swell.
Values for the LOW-ACN condition
Other XNBR grades and fills
XNBR is listed in 10 conditions; see the grade overview at XNBR.
Compare all 10 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Flame-retardant XNBR | Mining conveyor belt covers, cable jackets and rail interiors requiring self-extinguishing behaviour; heavy mineral loading reduces tensile and tear. | — | 14 | 320 | 25 Shore D |
Shore A 50 | Soft, high-elongation grade for low-pressure gaskets, diaphragms and flexible boots where sealing on rough flanges matters more than extrusion resistance. | — | 16 | 570 | 8 Shore D |
ozone- and weather-resistant compound | Use where the part sees outdoor ozone, sunlight or fuel-hose duty; PVC gives weathering and flame resistance but raises low-temperature stiffness and compression set. | — | 20 | 400 | 22 Shore D |
Shore A 60 | General gasket and O-ring hardness with a good balance of sealing conformability and abrasion life. | — | 21 | 500 | 13 Shore D |
LOW-ACNThis page Low-ACN (≈18–26 % acrylonitrile) low-temperature XNBR | For cold-climate seals and belts needing flexibility to about −40 °C, at the cost of higher oil swell. | — | 22 | 500 | 16 Shore D |
A70Default Shore A 70 | Default industrial hardness: highest-volume XNBR compound for oil seals, rod wipers, hydraulic packings and abrasion-resistant rubber goods. | — | 25 | 450 | 20 Shore D |
Carboxylated nitrile latex | Aqueous XNBR latex dipped into thin films: the standard powder-free examination/industrial glove material, protein-free versus natural latex. | — | 25 | 550 | 10 Shore D |
High-ACN (≈33–40 % acrylonitrile) fuel/oil-resistant XNBR | Pick when swell in aromatic fuels, gear oils or aggressive additives must be minimised; accept a much colder brittle point penalty. | — | 27 | 400 | 20 Shore D |
Shore A 80 | Choose for high-pressure hydraulic seals, packer elements and backup rings where gap extrusion is the failure mode. | — | 28 | 340 | 30 Shore D |
Shore A 90 | For roll covers, wear liners and anti-extrusion components; near-maximum abrasion resistance but low elongation and poor sealing conformability. | — | 30 | 240 | 38 Shore D |
What is XNBR LOW-ACN?
XNBR LOW-ACN is XNBR in the LOW-ACN grade — for cold-climate seals and belts needing flexibility to about −40 °C, at the cost of higher oil swell. XNBR LOW-ACN has a tensile strength of 22 MPa (3.19 ksi), weaker than 69% of polymer grades. Elongation at break is 500% and the elastic modulus is 0.01 GPa (8.7×10⁻⁴ Msi). XNBR LOW-ACN has a density of 1.18 g/cm³ (0.0426 lb/in³), heavier than 50% of polymer grades. Its glass-transition temperature is -40°C (-40 °F). A70 is the default condition FabDigit quotes; LOW-ACN is available on request or by drawing note.
Advantages
- Forms and bends easily — 92/100, better than 97% of polymer grades
- Ductile — tolerates forming and impact — 500%, better than 90% of polymer grades
Limitations
- High mold shrinkage — 2.6%, worse than 96% of polymer grades
- Absorbs moisture — dry before molding — 1.5%, worse than 91% of polymer grades
- Needs corrosion protection — 62/100, worse than 87% of polymer grades
- Low stiffness — 0.01 GPa (8.7×10⁻⁴ Msi), worse than 86% of polymer grades
- Difficult to machine — 33/100, worse than 85% of polymer grades
XNBR LOW-ACN properties
Typical room-temperature values for XNBR LOW-ACN; 20 are specific to this condition. Other listed values are XNBR reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
XNBR LOW-ACN has a density of 1.18 g/cm³ (0.0426 lb/in³), heavier than 50% of polymer grades. Its glass-transition temperature is -40°C (-40 °F).
Mechanical9
XNBR LOW-ACN has a tensile strength of 22 MPa (3.19 ksi), weaker than 69% of polymer grades. Elongation at break is 500% and the elastic modulus is 0.01 GPa (8.7×10⁻⁴ Msi).
Thermal8
XNBR LOW-ACN is rated for continuous service to 100°C (212 °F). It conducts heat at 0.24 W/m·K (0.139 BTU/hr·ft·°F), better than 67% of polymer grades. Thermal expansion is 220 µm/m·K (122.2 µin/in·°F).
Electrical5
XNBR LOW-ACN is an electrical insulator with a dielectric strength of 16 kV/mm (406.4 V/mil) and a resistivity of 3×10⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 87% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of XNBR LOW-ACN takes about 110 MJ of energy and emits 4.2 kg of CO₂ — more than 64% of polymer grades. Typical recycled content is 3%.
Manufacturability6
XNBR LOW-ACN's machinability is poor (33/100, worse than 85% of polymer grades); weldability poor (15/100); formability excellent (92/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with XNBR LOW-ACN
Is XNBR easy to machine?
Machine only in the cured state — cryogenic deflashing, water-jet or die cutting, and wet grinding with sharp tooling; the tacky, high-friction surface tears with dull blades.
Can XNBR be welded?
Not weldable; join by hot vulcanized splice, uncured tie-gum bonding to metal (chemlok primers), or cyanoacrylate/polyurethane adhesive on abraded surfaces.
Can XNBR be formed, bent or molded?
Compression, transfer or injection mold at 150–190 °C; carboxyl groups raise Mooney viscosity and scorch risk, so keep barrel and mill stock below ~100 °C and use stearate/ZnO dispersion control.
What surface finishes work on XNBR?
Surfaces are as-molded or ground; use post-cure (2–4 h at 100–150 °C) to cut compression set, and chlorination or silicone/PU topcoat to lower tack on gloves and rolls.
XNBR chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| acrylonitrile (ACN)governs oil resistance and Tg | 18 – 40 | 28 |
| carboxylic acid monomer (acrylic/methacrsites for ZnO ionic crosslinking; source of abrasion/tear gain | 1 – 8 | 4 |
| carbon black (N330/N550)phr in the vulcanizate, not wt% of polymer | 20 – 70 | 45 |
| zinc oxidephr; ionic cure activator/crosslinker | ≈ 5 | 5 |
| sulfur or peroxide cure system + plasticphr, compound dependent | ≈ 10 | 10 |
| butadienebalance of polymer backbone | balance | — |
XNBR LOW-ACN — frequently asked
What is XNBR LOW-ACN used for?
XNBR LOW-ACN is typically used for conveyor belt covers, printing rollers, golf ball cores and wear-resistant gaskets. In short: most abrasion-resistant nitrile; tear-resistant NBR upgrade; roller and belt grade.
What is the tensile strength of XNBR LOW-ACN?
XNBR LOW-ACN has a typical tensile strength of 22 MPa (3.19 ksi) — weaker than 69% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is XNBR LOW-ACN easy to machine?
Not especially — machinability is rated poor (33/100, worse than 85% of polymer grades). Machine only in the cured state — cryogenic deflashing, water-jet or die cutting, and wet grinding with sharp tooling; the tacky, high-friction surface tears with dull blades.
Can XNBR LOW-ACN be welded?
Not readily — weldability is rated poor (15/100). Not weldable; join by hot vulcanized splice, uncured tie-gum bonding to metal (chemlok primers), or cyanoacrylate/polyurethane adhesive on abraded surfaces.
What surface finishes work on XNBR LOW-ACN?
Surfaces are as-molded or ground; use post-cure (2–4 h at 100–150 °C) to cut compression set, and chlorination or silicone/PU topcoat to lower tack on gloves and rolls.
Can XNBR LOW-ACN be formed, bent or molded?
Compression, transfer or injection mold at 150–190 °C; carboxyl groups raise Mooney viscosity and scorch risk, so keep barrel and mill stock below ~100 °C and use stearate/ZnO dispersion control.
What is the maximum service temperature of XNBR LOW-ACN?
XNBR LOW-ACN is rated for continuous use to about 100°C (212 °F), and briefly to 125°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Krynac X carboxylated nitrile rubber grade data — ARLANXEO / Lanxess (2022)
- Nipol NX series carboxylated NBR technical data — Zeon Corporation (2021)
- Engineered Materials Handbook Vol. 2 — Engineering Plastics & Elastomers — ASM International (1988)
- Rubber Technology: Compounding and Testing for Performance — Hanser (2009)
- ASTM D2000 — Classification System for Rubber Products in Automotive Applications — ASTM (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.