UHMW Properties — Friction, Impact & Abrasion Data

UHMW-PE (ultra-high molecular weight polyethylene) earns its place in wear and liner applications through a combination of properties that no other commodity plastic replicates: a coefficient of friction of 0.10–0.20 (the lowest of any unfilled thermoplastic), Izod impact strength that exceeds the test method's measurable limit at room temperature, and abrasion resistance roughly 6× better than nylon 6/6. This page provides the full property dataset engineers and buyers need to specify and qualify UHMW in a design.

At a glance:

• Dynamic coefficient of friction (steel): 0.10–0.20 (dry)
• Notched Izod impact: 25+ ft-lb/in (no break per ASTM D256)
• Tensile strength: ~5,800 psi (ASTM D638)
• Abrasion resistance: ~6× nylon 6/6 (ASTM D4060 Taber)
• Continuous use temperature: 180°F (82°C); short-term peak ~210°F (99°C)
• Density: 0.93 g/cc — lower than water; UHMW sheet floats
• Shore D hardness: 65–68; Rockwell R ~64

Mechanical Properties

Tensile and Flexural

UHMW is not a structural material. Its tensile strength of approximately 5,800 psi and tensile modulus of roughly 100,000–115,000 psi are modest — far below nylon (8,000–11,000 psi tensile) or acetal (10,000–14,000 psi). The value proposition is surface behavior (friction, abrasion) and toughness, not load-bearing capacity. Where UHMW panels are used structurally — dasher boards, marine panels — they carry lateral and impact loads in bending, not axial compressive or tensile loads.

The high elongation at break (300–400%) reflects UHMW's molecular architecture — the extremely long polymer chains slide past each other rather than fracturing catastrophically. This is the same property that produces the no-break Izod result.

Impact Strength

Standard notched Izod testing (ASTM D256) cannot measure UHMW's impact strength because specimens do not fracture; the energy absorbed exceeds the pendulum's capacity. Values are reported as "no break" or ">25 ft-lb/in," though some laboratories record individual specimen values as high as 80–100 ft-lb/in using modified test setups. For comparison, nylon 6/6 notched Izod is 1.5–2.0 ft-lb/in; acetal is 1.2–2.3 ft-lb/in.

This toughness is retained at sub-zero temperatures. UHMW remains ductile to approximately −40°F (−40°C), which is why it is specified for frozen food plant liners, cold-storage conveyor guides, and ice rink dasher applications. See UHMW grades and specialty compounds for Tivar 1000, which extends low-temperature performance further.

Hardness

UHMW's hardness is lower than acetal (Rockwell M78) and nylon (Rockwell R108–120 on harder grades), which contributes to its machinability challenges — the material is soft and gummy under tooling. See the UHMW machining guide for correct approach.

Tribological Properties — Friction and Wear

Coefficient of Friction

These values are for unlubricated sliding contact. UHMW's friction is approximately equivalent to lubricated HDPE or lubricated nylon, but without any lubricant required. This is the primary reason UHMW is preferred over nylon in dry-running conveyor guides and food-zone wear strips — no lubricant means no contamination risk.

PTFE/Teflon has a lower coefficient of friction (0.04–0.10) than UHMW in most test configurations, but PTFE is far more expensive, mechanically weak, and prone to cold flow under load. PTFE vs. UHMW is covered in detail in the comparisons section.

Abrasion Resistance

Abrasion is measured per ASTM D4060 using a Taber Abraser (CS-17 wheel, 1 kg load, 1,000 cycles). UHMW consistently shows a wear index approximately 6× better than nylon 6/6. Against HDPE, the advantage is typically 2–4× depending on the specific grade pairing and test conditions.

Thermal Properties

Temperature Limits

UHMW is a semi-crystalline polymer with a crystalline melting point around 266–279°F (130–137°C). Practical continuous-use limits are set well below that to account for creep and dimensional instability under load.

At temperatures above 140°F (60°C) under sustained compressive load, UHMW creeps noticeably. For elevated-temperature wear applications, PTFE/Teflon (continuous use to 500°F) is the typical upgrade path, though at significantly higher cost.

Thermal Expansion

The coefficient of linear thermal expansion (CLTE) for UHMW is approximately 8–11 × 10⁻⁵ in/in/°F (ASTM E831). This is significantly higher than most metals (steel: 0.65 × 10⁻⁵) and higher than acetal or nylon. Gaps must be designed into fastened liner panels to accommodate thermal expansion — a 48" wide UHMW sheet will expand approximately 0.19" over a 40°F temperature swing. Failing to account for this is the leading cause of UHMW liner buckling in installations.

Dimensional Stability

UHMW combines very low water absorption with a high coefficient of thermal expansion — a combination that requires attention in precision applications.

Water Absorption

Water absorption at 24-hour immersion (ASTM D570) is less than 0.01%. This means UHMW does not swell in wet environments, does not change dimensions when moving between wet and dry service zones, and does not develop the subsurface moisture that causes nylon to lose dimensional tolerance in humid conditions. For food processing applications where the material alternates between wet production and dry sanitation, UHMW maintains consistent fit and clearance over the operating cycle.

Thermal Expansion

The coefficient of linear thermal expansion (CLTE) is approximately 8–11 × 10⁻⁵ in/in/°F, which is among the highest of engineering thermoplastics. For comparison, acetal (POM) is approximately 5.5 × 10⁻⁵ in/in/°F and nylon 6/6 is approximately 4.5 × 10⁻⁵ in/in/°F. The practical implication: UHMW liner panels installed at 40°F will be approximately 0.19" wider (across a 48" span) at 80°F. Panel joints must include designed-in expansion gaps, and fastener holes in UHMW should be oversized slots rather than round holes wherever thermal cycling is expected.

Creep and Stress Relaxation

Under sustained compressive load, UHMW creeps. The creep rate increases with temperature and applied stress. At ambient temperature (70°F) under 500 psi compressive load, UHMW will deform approximately 1–2% over 1,000 hours. At 140°F under the same load, the creep rate roughly doubles. For press-fit or interference-fit applications where UHMW is used as a bushing or insert, design the fit for the end-of-life (crept) dimension rather than the as-installed dimension. Anti-creep design strategies include using compression limiters (metal shoulder bolts or inserts), reducing contact stress, and lowering service temperature where possible.

Electrical Properties

UHMW is an electrical insulator with a volume resistivity greater than 10¹⁵ ohm·cm. Standard grades will accumulate static charge when sliding on dry media (powder, granules, pellets). Tivar Cleanstat and Tivar HPV anti-static grades dissipate charge below the incendiary threshold (surface resistivity 10⁶–10⁹ ohm/sq), which is required in pharmaceutical filling, explosive dust, and certain food applications. See UHMW grades for anti-static options.

Chemical Resistance

UHMW provides excellent resistance to:

• Dilute and concentrated aqueous acids (sulfuric, hydrochloric, phosphoric below 60°F)
• Aqueous bases and caustics (sodium hydroxide, ammonia solutions)
• Alcohols, ketones (at room temperature)
• Aqueous salt solutions, brine, seawater
• Most aqueous cleaning agents and sanitizers

UHMW is attacked or swollen by:

• Aromatic hydrocarbons (toluene, xylene) at elevated temperatures
• Chlorinated solvents (methylene chloride, trichloroethylene)
• Strong oxidizing acids at elevated temperatures (nitric acid, hydrogen peroxide >30%)

For aggressive chemical environments that also require low friction, PTFE/Teflon offers near-universal chemical resistance.

Regulatory and Compliance Properties

Natural (white) virgin UHMW is the most broadly compliant grade. Black and colored grades may carry FDA certification if produced from FDA-listed pigment packages — confirm with the material certification. Reprocessed UHMW does not carry FDA certification regardless of color. Full compliance details are on the UHMW FDA food-grade page.

Summary Property Table

More related guides

Cross-cluster suggestions to help shoppers and engineers explore adjacent topics:

Applications

• Bushings Bearings
• Wear Strips Guide Rails
• Food Zone Fda

Industries

• Food Beverage
• Marine

Compare to other materials

• Uhmw Vs. Hdpe
• Uhmw Vs. Polypropylene
• Uhmw Vs. Ptfe Teflon

Frequently asked questions — Uhmw FAQ