Why the jacket matters as much as the conductor
It's easy to spec a cable by conductor gauge and shielding and treat the jacket as an afterthought, but the jacket material is what actually determines whether that cable survives its environment — the temperature swing, the oil exposure, the constant flexing, or the fire-code requirement of the space it's routed through. A cable with perfectly adequate conductors and shielding can still fail in the field because the jacket cracked in cold storage, softened near a heat source, or degraded on contact with cutting fluid. This guide covers the six materials that show up most often on connectorselection.com's own product and application content, with the practical trade-offs that actually drive a selection decision.
PVC (Polyvinyl Chloride)
The default general-purpose jacket material, and still the most common one in fixed installations and consumer electronics.
Temperature range: roughly -15°C to 70°C in typical general-purpose formulations (higher-temperature PVC compounds exist — always check the specific compound's datasheet rather than assuming a single number applies).
Abrasion resistance: good for a general-purpose material.
Chemical/oil resistance: moderate — oil-resistant PVC formulations exist as a distinct spec from standard PVC, so "PVC" alone doesn't guarantee oil resistance.
Flexibility: moderate; stiffens noticeably at low temperatures, which is the most common reason PVC gets ruled out for an application.
Flame behavior: flame retardant by formulation, but PVC contains halogens and emits toxic, corrosive smoke when it burns — a real disqualifier for enclosed spaces like data centers, transit vehicles, or any application under an LSZH requirement.
Cost: the lowest of the common jacket materials, and the main reason it remains the default for cost-sensitive, low-voltage, indoor applications.
PUR (Polyurethane)
The step up from PVC when the application involves real mechanical or chemical stress rather than just routing wires indoors.
Temperature range: roughly -50°C to 105°C, with genuine low-temperature flexibility rather than just a cold-rated spec — PUR stays rubber-like in cold conditions where PVC stiffens.
Abrasion resistance: notch- and abrasion-resistant, a meaningful step above PVC.
Chemical/oil resistance: the best oil and chemical resistance of the common jacket materials, which is why it shows up so often in machine tool, automotive, and industrial cabling.
Flexibility: high — highly bend-resistant and well suited to cables that move repeatedly in service.
Flame behavior: available halogen-free and self-extinguishing.
Cost: meaningfully higher than PVC.
Typical applications: machine tools, plant/industrial equipment, automotive wiring, drag-chain and other cables that combine motion with chemical exposure.
TPE (Thermoplastic Elastomer)
The material of choice when the priority is flexibility across a wide temperature swing, especially in cold conditions.
Temperature range: roughly -35°C to 100°C in the tighter ranges seen in some formulations, up to -50°C to 125°C in others — TPE covers a genuinely broad span depending on the specific compound, wider than the "TPE" label alone tells you.
Abrasion resistance: good; handles mechanical loading well.
Chemical/oil resistance: good resistance to oils, UV, and abrasion, often cited as excellent across the board for a thermoplastic elastomer.
Flexibility: excellent, including in cold conditions — this is TPE's defining strength relative to PVC.
Flame behavior: available halogen-free or flame-retardant (commonly UL 94-HB rated).
Cost: moderate — more than PVC, generally comparable to or somewhat below PUR.
Typical applications: robotics, sensors, crane and material-handling equipment, and other dynamic machinery that needs both flexibility and cold-weather performance.
TPU (Thermoplastic Polyurethane)
Closely related to PUR — the two terms are sometimes used loosely and interchangeably in cable marketing, but TPU is specifically the thermoplastic (melt-processable) form of polyurethane, distinct from thermoset PUR compounds. In practical jacket terms, expect TPU to track closely with PUR's abrasion resistance, oil resistance, and flexibility profile; the meaningful engineering question when a datasheet says "TPU" or "PUR" is which specific hardness grade and formulation was used, not the acronym itself. When in doubt, request the actual datasheet rather than assuming TPU and PUR are always interchangeable for a given spec.
Silicone
The material for genuinely extreme temperature applications, at a real cost premium.
Temperature range: roughly -60°C to 200°C — by far the widest range of any common jacket material, and the only one of this group that handles sustained high-heat exposure.
Abrasion resistance: moderate — not silicone's strong suit relative to PUR or TPE.
Chemical/oil resistance: weaker oil resistance than PUR or TPE; not the right choice for an oily environment even though it excels at temperature extremes.
Flexibility: excellent across its entire temperature range, and biocompatible formulations exist for medical use.
Cost: the highest of the materials covered here.
Typical applications: medical devices and sterilizable equipment, aerospace, and any application with sustained high-heat exposure — near motors, ovens, or industrial heat sources — where PUR's 105°C ceiling isn't enough.
LSZH (Low Smoke Zero Halogen)
LSZH isn't a single base polymer the way PVC or PUR are — it's a compound family (often polyolefin-based) engineered specifically to emit very little smoke and no halogen gases when it burns, rather than to optimize temperature range or flexibility.
Temperature range: roughly -40°C to 90°C, narrower than PUR or TPE.
Flexibility: the least flexible of the materials covered here, a real trade-off against its safety profile.
Flame behavior: the entire point of the material — fire-safe, with minimal smoke and no toxic/corrosive halogen gas released, which matters enormously for occupant safety and equipment protection in enclosed spaces during a fire.
Cost: high.
Typical applications: data centers, transit and rail systems, and any enclosed occupied space where fire code specifically calls for low-smoke, halogen-free cabling — this is a compliance-driven choice more than a performance one.
Quick reference
PVC — -15°C to 70°C; moderate flexibility; moderate oil/chemical resistance (oil-resistant grades exist separately); halogenated, toxic smoke when burned; lowest cost.
PUR — -50°C to 105°C; high, cold-flexible; the best oil/chemical resistance of the group; halogen-free and self-extinguishing; high cost.
TPE — -35°C to 125°C depending on formulation; excellent, cold-flexible; good oil/chemical resistance; halogen-free or flame-retardant; moderate cost.
TPU — similar range and flexibility to PUR; similar oil/chemical resistance to PUR; flame behavior formulation-dependent; high cost.
Silicone — -60°C to 200°C, the widest range here; excellent flexibility across that whole range; weak oil/chemical resistance; inherently flame-resistant; highest cost.
LSZH — -40°C to 90°C; the least flexible of this group; oil/chemical resistance formulation-dependent; fire-safe with zero halogen emission; high cost.
How to actually choose
Work backward from the single hardest constraint the application imposes, rather than trying to optimize every property at once — no jacket material wins on all of them. If the deciding factor is sustained heat, silicone is close to the only real option above roughly 105°C. If it's oil or chemical exposure on moving equipment, PUR (or TPU) is the standard answer. If the cable needs to stay flexible through a genuine cold-weather swing without silicone's cost or oil-resistance weakness, TPE is usually the better fit than PUR. If the application sits inside a code-driven fire-safety requirement — a data center, a transit vehicle, any enclosed occupied space — LSZH isn't really optional once that requirement applies, regardless of what else might look attractive on paper. And for straightforward indoor, fixed, low-voltage runs with no unusual environmental stress, PVC remains the reasonable default precisely because the other five materials are all solving a problem that application doesn't actually have.
For a direct side-by-side of the three most common general-purpose options, see the PVC vs. PUR vs. TPE comparison.
Related reading
What Is a Wire Harness? Complete Guide for Engineers
Why Raw Cables Use Fillers, Splines & Paper Wraps
Cable Temperature Ratings: Current Derating & Voltage Drop
Overmolded Cable Assemblies Explained
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