Why our HRI made of Urethane

urethane’s main attributes (talking about polyurethane, which is what people mean when they say “urethane” in this context):

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Physical Properties

Attribute	Typical Range / Info	Notes
Hardness	Shore A 10 → Shore D 80	Can be soft rubber-like or hard plastic-like depending on formulation
Tensile Strength	2,000–6,000 psi (14–41 MPa)	Strong for a polymer but far below metals
Elongation at Break	100–600%	Can stretch a lot before breaking (elastic)
Abrasion Resistance	Excellent	Much better than rubber, resists wear
Impact Resistance	Good	Absorbs shocks without cracking
Density	1.1–1.3 g/cm³	Similar to hard plastics
Compression Set	Low	Springs back after compression

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Environmental Resistance

Attribute	Performance	Notes
Water Resistance	Excellent	Stable in water exposure
Oil & Grease Resistance	Good to Excellent	Better than most rubbers
UV Resistance	Fair to Poor	Can yellow and degrade without UV stabilizers
Temperature Range	-30°C → +80°C (some up to +120°C)	High-heat grades available
Chemical Resistance	Good to many chemicals, but weak to strong acids/bases	Varies by formulation

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Pros

• Very wear resistant (better than natural rubber)
• Elastic yet tough
• Good damping for vibration/noise
• Can be cast, machined, or injection molded
• Bonds well to metals (good for overmolds)

Cons

• Not as strong as metals for structural loads
• Can yellow or degrade under UV unless stabilized
• Heat resistance is moderate
• Can absorb moisture slightly over time

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If you’re considering urethane for a hitch receiver insert, the takeaways are:

• 👍 Great for protective caps, bump stops, and coatings
• ❌ Not a good stand‑alone structural towing insert (needs a metal core)

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