---
title: "Oil and Fuel Resistance of Polyurethane Parts: Comparison with Rubber and Caprolon"
description: "Detailed insights on TIMOL polyurethane's oil and fuel resistance: comparison with rubber and caprolon, hardness selection, installation, and custom orders. Contact us for consultation."
lang: "en"
date: "2026-10-03"
canonical_url: "https://timol.com.ua/en/statti/maslobenzostikist-poliyuretanovikh-detaley"
---
# Oil and Fuel Resistance of Polyurethane Parts: Comparison with Rubber and Caprolon

Failure of seals, rings, or bushings due to swelling in oil or diesel fuel often halts an entire line unexpectedly. Rubber parts frequently fail within weeks, especially in units where lubricant or fuel is constantly present. Switching to polyurethane not only prevents swelling but also provides a lifespan 10 times longer without installation complications. In this article, we explore why TIMOL polyurethane leads in oil and fuel resistance, how to choose the optimal hardness, which units it suits better than rubber or caprolon, and what to consider when ordering a custom part.

## Why Polyurethane is Resistant to Oils and Fuels
TIMOL polyurethane demonstrates high oil and fuel resistance due to its chemical structure: its polymer network lacks soluble fragments that could react with hydrocarbons. As a result, even with prolonged contact with mineral oils, hydraulic fluids, or diesel fuel, polyurethane parts do not swell, delaminate, or lose shape. This is particularly valuable in seals, gaskets, and bushings, where any change in geometry leads to loss of sealing or jamming of the unit.

In practice, the oil and fuel resistance of polyurethane is confirmed in units with constant lubrication: for example, in hydraulic cylinders, gearboxes, oil baths, where rubber parts eventually degrade or become brittle. TIMOL polyurethane products maintain stability even in complex mixtures of oils and diesel fuel. Thanks to the free casting technology, the factory can produce parts of any complexity with minimal shrinkage and no pores.

Moreover, polyurethane does not soften or leach components under the influence of fuels, a common issue with traditional rubbers (especially SBR and EPDM). This is critical for parts operating dynamically, with constant vibrations and temperature fluctuations.

## Comparative Table of Oil and Fuel Resistance and Wear Resistance
TIMOL polyurethane stands out from NBR, SBR rubber, and caprolon not only in oil and fuel resistance but also in wear resistance and working temperature range. The table below provides key parameters for practical material selection.

| Material | Abrasion DIN 53516 (mm3) | Working Temperature (°C) | Oil and Fuel Resistance | Hardness |
|------------------------|--------------------------|------------------------|---------------------|--------------------|
| Polyurethane (TIMOL) | 20-45 | -60...+100 | high | 50A - 70D |
| NBR Rubber | 80-150 | -30...+100 | good | 40A - 90A |
| SBR Rubber | 100-200 | -40...+80 | poor | 40A - 80A |
| Caprolon (PA6) | 30-90 | -40...+100 | good | 75D - 85D |

The abrasion of polyurethane according to DIN 53516 is only 20-45 mm3, while NBR rubber is 80-150 mm3, and SBR rubber wears even faster (100-200 mm3). This means that polyurethane lasts dozens of times longer than rubbers even in the presence of oils or fuels. Caprolon is also quite wear-resistant but lacks the elasticity of polyurethane and is less resistant to impact loads.

## Typical Application Units and Tasks for Oil and Fuel Resistant Polyurethane
The use of TIMOL polyurethane in oil and fuel environments covers a wide range of units and assemblies. Seals (gaskets, oil seals, rings) made of polyurethane are installed in pumps, hydraulic cylinders, transmissions, gearboxes, and other equipment where the constant presence of oil or fuel requires stable seal geometry. Bushings and guides are often used in gravity equipment, conveyors, belt lines, and mixers, where loads from lubricant and abrasive are combined.

In mining, metallurgy, oil, and machine-building industries, there is often a need for scrapers and belt cleaners resistant to oils and contaminants. Here, polyurethane excels not only in resource but also in its ability to "repel" abrasive and not "stick" in lubricant. Polyurethane products are suitable for a wide temperature range, from -60 to +100 °C, allowing their use in open sites and closed oil baths without the risk of cracking or losing elasticity.

Parts are manufactured by the free casting method: this allows for precise reproduction of complex seal profiles, manufacturing rings, bushings, guides of any diameter and thickness without significant mechanical processing. For serial production, casting molds ensure stable quality and dimensional repeatability.

## Real Advantages of Polyurethane over Rubber and Caprolon in Oil Units
TIMOL polyurethane has wear resistance 10 times higher than standard rubber, does not swell or soften in environments of oils, diesel fuel, hydraulic fluids. Although NBR rubber is considered oil and fuel resistant, it loses to polyurethane in wear resistance and dimensional stability under abrasive loads. SBR rubber is entirely unsuitable for such conditions and quickly deteriorates. Caprolon shows good oil and fuel resistance but is not elastic: it is brittle to impacts, does not dampen vibrations, and can crack under sudden load changes, especially in units with play or misalignment.

An important feature of polyurethane is its stable retention of elasticity and shape across the entire range from -60 to +100 °C. This allows its use in conditions where rubber or plastic would lose functionality. Additionally, polyurethane performs well in units with cyclic loads, where movement compensation or rotation is required.

> **Engineer’s Tip:** For abrasive and oil and fuel resistant units, choose polyurethane hardness in the range of 80-95 Shore A: this provides a combination of resilience and stable shape when in contact with oils and light abrasives. For seals and gaskets in hydraulic systems, 70-90 Shore A is recommended. The exact choice depends on working pressure, type of environment, and unit design.

## Choosing Polyurethane Hardness for Oil and Fuel Environments
The optimal hardness of polyurethane determines not only wear resistance but also the behavior of the part in the unit. For scrapers, bushings, and lining parts working with lubricant and abrasive, the ideal range is 80-95 Shore A: these are hard yet resilient products that will absorb impacts and not chip or crack under mechanical stress. For seals and gaskets, where elasticity is important for movement compensation and sealing, 70-90 Shore A is preferable.

Production by the free casting method allows precise control of hardness by selecting the polymer formulation and technological process. TIMOL factory manufactures parts with individually specified hardness, according to drawings, sketches, or customer samples. This is especially valuable for non-standard units where precise compliance with operational requirements is needed.

## Installation, Maintenance, and Manufacture of Custom-Sized Polyurethane Parts
Most TIMOL polyurethane parts (e.g., sealing rings, bushings, guides) are compatible with the mounting locations of rubber and plastic products without additional unit modification. Installation is performed manually or with press equipment, depending on the size and type of part. For quick-release units, it is recommended to use polyurethane rings and bushings with chamfers or special grooves to facilitate installation.

Maintenance of polyurethane parts involves periodic checks for wear and integrity. Unlike rubber, polyurethane does not require surface treatment to enhance oil and fuel resistance, as it is already inert to lubricants. In case of replacement or manufacturing a new part to size, simply provide a drawing, sketch, or sample, and the TIMOL factory will perform the calculation and manufacturing. Explore the range in the [polyurethane products catalog](/katalog), and for consultation, use the [reference information](/informatsiya) or contact us through [contacts](/contacts).

## Considerations When Switching from Rubber or Caprolon to Polyurethane
Before replacing rubber or plastic parts with polyurethane ones, it is important to consider several aspects. First, determine the type of lubricant or fuel in the unit: TIMOL polyurethane is compatible with most mineral oils, diesel fuel, transmission, and hydraulic fluids. Second, pay attention to the working temperature range: the range of -60 to +100 °C covers the majority of industrial tasks. Third, select the hardness for the specific task considering the nature of the loads, abrasive, vibration, dynamic deformations, or sealing.

TIMOL factory provides consultation on selecting the composition and hardness of polyurethane, and adapts the technology to your requirements. For particularly complex units, it is possible to produce a trial batch for testing and further optimization. Read more about the material and technology in the [reference section](/informatsiya).

## Practical Conclusion: When to Switch to TIMOL Polyurethane
If a unit regularly fails due to swelling or destruction of rubber or plastic parts in oil or diesel fuel, switching to TIMOL polyurethane will significantly increase lifespan and ensure stable operation from -60 to +100 °C. Polyurethane combines high oil and fuel resistance with resilience, wear resistance, and geometric stability. For selecting the optimal hardness and manufacturing a custom-sized product, contact the factory engineers through [contacts](/contacts) or choose a solution in the [catalog](/katalog). The free casting technology allows solving the most complex tasks for 12 industries.