PTFE vs Nylon vs Delrin vs PEEK: Choosing the Right Engineering Plastic for Industrial Use 

When engineers, OEM purchasers, and procurement teams are confronted with the issue of selecting an industrial plastic material, four names are again and again mentioned: PTFE, Nylon (PA), Delrin (POM/Acetal), and PEEK. These engineering plastics have different sets of characteristics (including chemical resistance, temperature capability, friction, load-bearing strength, dimensional stability, machinability, and cost) and each is tailored to quite different industrial conditions.

Using the unsuitable material may lead to premature failure of part, expensive downtimes, and safety hazards. The correct choice could be used to save weight, increase service life, and also perform better even in the worst conditions. The guide is a breakdown of the PTFE vs Nylon vs Delrin vs PEEK comparison on all the most important parameters, to have a data-driven sourcing decision.

At Aashish Metals, we stock all four materials in industrial forms — rods, tubes, sheets, and bushes — enabling engineers to source the exact grade and profile they need.

What Are These Four Engineering Plastics?

PTFE (Polytetrafluoroethylene) — Also Known as Teflon

PTFE is a fluoropolymer that is characterized by one of the lowest coefficients of friction of any solid substance and almost complete PTFE chemical resistance. It is totally hydrophobic -it takes up no moisture- and can be used at sustained service temperatures to 260C, again because of its gummy nature it is hard to machine to fine tolerances and has low tensile strength and cannot be used in structural or load bearing applications. PTFE finds application in seals, gaskets, chemical liners and non-stick. Browse our PTFE Rod range to explore available sizes.

Nylon (PA6 / PA66) — The Workhorse Bearing Plastic

Nylon is a low cost, relatively tensile strength (at about 80 Mpa) and toughness, with ease of machining, making it one of the most common engineering plastics in the world. Nevertheless, Nylon vs Delrin comparisons always present one of the biggest weaknesses of Nylon, which is the high moisture absorption. When exposed to a humid or wet atmosphere, Nylon may swell and lose dimensional accuracy, and have severe loss of strength. It grows well under dry and moderate temperatures. Learn more about Nylon material properties and applications on the Aashish Metals blog.

Delrin (POM / Acetal) — The Precision Engineering Plastic

The POM-H (homopolymer acetal) is called Delrin by DuPont trade name, and the copolymer acetal is known as POM-C. Delrin has always been a better choice over PTFE or Nylon in a Delrin vs PTFE or Nylon vs Delrin comparison due to excellent machinability, high dimensional stability in wet conditions, and high wear resistance, as well as predictable mechanical characteristics. It can manage temperatures up to 100-120 o C and the moisture absorption is low, making it suitable in precision gears, bushings, sliders and moving mechanical parts. Explore our Delrin Tubes available in multiple dimensions.

PEEK (Polyether Ether Ketone) — The High-Performance Champion

When it comes to a discussion of PTFE vs PEEK or PEEK vs Nylon properties, PEEK can be discussed as the high-grade engineering thermoplastic. It has excellent dimensional stability, continuous service temperatures up to 250-300 C, best in class wear resistance and is resistant to practically all chemicals. Its tensile strength of about 100 Mpa is comparable to that of metals in some applications. The trade-off is cost PEEK is a lot more expensive than all three options. It is the product of choice in aerospace, medical, semiconductor, and high performance industrial parts. Source PEEK Tubes directly from Aashish Metals for verified industrial-grade stock. 

PTFE vs Nylon vs Delrin vs PEEK: Full Engineering Plastics Comparison Table

The table below provides a comprehensive engineering plastics comparison across the properties most critical to industrial material selection. Data drawn from established industry testing standards and supplier technical data sheets.

Table 1: Engineering plastics comparison — PTFE vs Nylon vs Delrin vs PEEK across key industrial properties.

Deep Dive: Head-to-Head Property Analysis

1. PTFE Chemical Resistance vs PEEK, Nylon, and Delrin

The resistance to chemical is legendary with PTFE. The complete operating temperature of PTFE, extending to 260 o C, is virtually insensitive to acid, base, solvents, and oxidising agents. It has the ability to resist concentrated sulphuric acid, hydrofluoric acid and strong alkalis unlike many other plastics. The other material in this category that is close to the chemical inertness of PTFE is PEEK, which is resistant to nearly all industrial chemicals except some concentrated acids at high temperatures. Delrin has fair resistance to oils, fuels and light solvents but is susceptible to strong acids and oxidising agents. Nylon is the most vulnerable one, it is vulnerable to acids, bases, and long-term contact with moisture, therefore restricting its use to chemically hostile conditions.

2.Thermal and Temperature Resistance.

In terms of engineering plastics comparison based on temperature capability: PEEK has the highest continued service temperature of 250-300o C, followed by PTFL with a maximum continuous temperature of 260 o C. Both Nylon and Delrin can be used successfully to 100-120o C although beyond this point, mechanical properties are no longer relied upon. Only PTFE or PEEK should be used in applications with high process temperatures i.e. chemical processing, oil and gas, aerospace or automotive. Delrin and Nylon are also cheaper substitutes in moderate-temperature conditions.

3. Friction, Wear Resistance and Tribology Performance.

PTFE is the material with the lowest coefficient of friction among the four materials 0.04-0.10 which is why it is the best choice as a seal, slide bearing, or where reduction of friction is of the utmost priority. The very soft structure of PTFE however, causes it to wear out easily when it is subjected to abrasive or high load. PEEK provides the most wear resistance of the lot especially when subjected to heavy loads and high temperatures, and is therefore preferred in gears, bearings, and bushings in high-demand applications. Delrin (POM) is a medium between the two: it has good machinability, low friction, and abrasion resistance, so it is a good performer in precision moving parts. Nylon is fairly wearable in dry conditions and decays more easily in wet conditions because of absorption of moisture.

4. Moisture Absorption and Dimensional Stability.

Dimensional stability is possibly one of the most stark differences in a Nylon vs Delrin comparison. Nylon takes in large amounts of moisture in the environment, leading to swelling, loss of mechanical strength, and inaccuracy in dimensions, which is a major issue with precision-machined parts. Delrin (POM) is highly resistant to moisture uptake and its size can be counted upon to remain consistent in wet and humid conditions, so it is used in precision gears, sliding guides, and parts that have tight tolerances. PTFE retains zero moisture yet creeps when subjected to constant load and this should be considered when designing. PEEK is dimensionally stable under almost all conditions, even when it comes to being exposed to steam, hot water, and most chemicals.

5. Machinability and Fabrication

Delrin (POM) is considered to be the most machineable engineering plastic of this category. It is clean to machine using standard tools, tolerant, and provides high-quality surface finishes. Nylon can also be machined, although it will flex in the cutting operation and can be less easy to hold to close tolerances. PEEK has a need of carbide tooling and prudent machining parameters yet attains good dimensional accuracy. The PTFE is also infamously hard to machine to close tolerances – it is mushy and gummy and creepy and thus difficult to machine accurately. In applications where the geometry and tight tolerance are of utmost importance, then Delrin or PEEK should be used.

6. Cost and Commercial Availability

Nylon (PA) is the cheapest of the four and is commonly available, and can be used in cost sensitive applications where high performance is not of the essence. Delrin (POM) occupies a middle price range, it is a high-performance material with a high price, yet a moderate cost, that is, the perfect choice of mid-range engineering plastic material in most industrial applications. The specialised fluoropolymer chemistry of PTFE makes this substance pricier than Nylon and Delrin. PEEK is by far the most expensive in the group, a high-grade material which is used in situations when none of the other materials can be utilized to fit the specification criteria. 

Industrial Plastic Material Selection Guide: Which One Should You Choose?

The right choice depends on your specific application demands. Below is a decision framework based on the most common industrial use cases:

• Choose PTFE when: You need maximum chemical resistance, ultra-low friction, zero moisture absorption, and continuous operating temperatures up to 260°C — for seals, gaskets, chemical liners, and low-load sliding elements. Source our PTFE Rod range.
• Choose Nylon (PA) when: Budget is the primary constraint, the operating environment is dry and at moderate temperatures, and you need a tough, flexible material for bearings, conveyor rollers, and cable insulation. Explore Nylon material resources.
• Choose Delrin (POM / Acetal) when: You need a precision-machinable, dimensionally stable plastic with excellent wear properties for gears, bushings, sliders, guide rails, and food machinery components. Browse our Delrin Tubes.
• Choose PEEK when: The application involves extreme heat (above 200°C), aggressive chemicals, high mechanical loads, and critical dimensional stability — for aerospace, medical, semiconductor, and oil and gas components. Source PEEK Tubes from Aashish Metals.

For a broader view of our complete engineering plastics portfolio — including rods, sheets, tubes, and bushes across all four materials — visit our Plastic Products Hub.

Industry-Wise Application Guide for PTFE, Nylon, Delrin, and PEEK

Understanding how each material performs across different industries helps engineers make faster, more confident engineering plastics comparison decisions:

Table 2: Industry application matrix for PTFE, Nylon, Delrin, and PEEK. 

Key Pairwise Comparisons: PTFE vs PEEK, Delrin vs PTFE, Nylon vs Delrin

PTFE vs PEEK: When to Choose Which

The PTFE vs PEEK trade off is usually a matter of trade off between chemical resistance and mechanical strength. The two materials work with extreme temperatures and harsh chemicals, though, PEEK offers much better mechanical characteristics, such as higher tensile strength, increased wear resistance, and increased dimensional stability under loading. In the case of minimisation of friction and when the structural loading does not constitute an issue, PTFE is chosen. PEEK is the ideal selection when the component is subjected to considerable mechanical load and at the same time, is exposed to heat and chemical.

Delrin vs PTFE: Machinability and Dimensional Precision

The most important distinguishing characteristics between Delrin and PTFE are machinability and load bearing. Delrin machines to tight tolerances easily and does not lose dimensional accuracy in wet conditions. PTFE is not easy to retain tight tolerances and creeps under constant load. Delrin is the obvious choice in precisely machined parts – gears, bushings, guide rails, etc. PTFE is unsurpassed in the low-friction, chemically resistant sealing elements.

Delrin vs nylon: The Moisture Stability Dilemma

Comparison between Nylon and Delrin is a common experience in specification of bearing and bushing materials. They both machine fairly well and provide good strength, but the ability of Delrin to absorb moisture dramatically less than other materials provides it with a significant edge in the environment where humidity, exposure to water, or even washing cycles are a standard practice. Delrin is better when dimensional consistency is of concern (which is the case with most precision engineering applications). Nylon is cheapest and can be used in dry and low precision.