Performance Terms, Defined with Limits
A performance word on a datasheet is only as strong as the test behind it. This page defines the eight terms our ranges use, states what must be tested before each claim is honest, and marks where each claim stops. Use it to read our product pages, and any competitor's.
Halogen-free
Definition. The compound contains no halogen elements (chlorine, bromine, fluorine as additives), so it releases minimal corrosive or toxic gas when heated.
What must be tested. Halogen content of the specific compound batch, not the polymer family. Standards such as RoHS and customer-specific lists (our DRS range declares RoHS, TÜV-PAHs, Sony SS-00259) anchor the measurement.
Limit. Halogen-free says nothing about flame behavior, dielectric or temperature. A halogen-free compound can burn readily. Specify the full property set, not the single label.
Verified pages → DRS range · FR 2:1 range
Flame-retardant
Definition. The tube resists flame propagation under a named test method: self-extinguishes within the method's limits.
What must be tested. The exact method: UL 224, VW-1, or an IEC equivalent, on the grade and wall in question. Results do not transfer between walls or colours without retest.
Limit. "Flame-retardant" without a method number is a marketing word. It also does not mean fireproof: sustained flame or the stated temperature beyond the rating defeats any polymer tube.
Verified pages → FR tubing (UL 224 declared) · fluoropolymer family (UL 94 V-0 declared)
Chemical resistance
Definition. The wall keeps its mechanical and dielectric properties after exposure to a named fluid for a stated time at a stated temperature.
What must be tested. Immersion or exposure against the specific fluid: fuels, solvents, hydraulic oils each differ. No universal "chemical-resistant" polymer exists.
Limit. We publish chemical resistance as a purpose for the fluoropolymer family, but the fluid-versus-grade table is not on the site; the claim is only honest when the fluid is named and the grade confirmed. Treat any blanket chemical claim as unverified.
Verified pages → PTFE/FEP/PFA family · PFA 2:1
High temperature
Definition. A continuous operating band, stated as two numbers, within which the wall keeps its rated properties.
What must be tested. Continuous heat ageing on the grade; peak (short-term) values must be stated separately from continuous ones.
Limit. The band is per grade, not per family: polyolefin stops at +125 °C published, silicone reaches +200 °C, fluoropolymer +260 °C, polyimide composite +400 °C. Never average these into one "high-temperature" claim: the lowest number in your assembly decides.
Verified pages → polyimide (+400 °C) · fluoropolymer (+260 °C) · silicone (+200 °C)
Abrasion resistance
Definition. The wall or braid survives rubbing contact against edges, clamps or moving parts for a duty cycle.
What must be tested. A mechanical abrasion method against a stated counterface: results vary hugely between a steel edge and a plastic clamp.
Limit. For the non-shrink families (PET braid, textile, fiberglass) abrasion behavior is the purpose of the product, but our pages do not publish cycle counts; treat comparative claims between families as unverified until a method is named. Heat-shrink walls are not abrasion products. Their thickness is sized for dielectric duty.
Verified pages → PET braid · textile wrap · woven sleeve
Adhesive / sealing
Definition. A dual-wall construction: the outer cross-linked wall recovers mechanically while the inner thermoplastic adhesive melts, flows and fills the interface: blocking axial water wicking.
What must be tested. Sealing integrity of the recovered joint (the adhesive's flow temperature and bond on your substrate matter).
Limit. The seal is only as good as full recovery: underheating leaves adhesive unmelted and the "sealed" joint open. An IP rating does not follow automatically from "adhesive-lined". It must be demonstrated for the assembly.
Verified pages → dual-wall 3:1/4:1 · breakout boot (adhesive-lined)
Heavy wall / medium wall
Definition. Wall classes of the recovered tube. Heavy wall (our busbar casing class) adds mechanical strength and larger creepage surface; thin wall prioritises flexibility and small bend radius.
What must be tested. Recovered wall thickness against the class and the dielectric withstanding at that wall.
Limit. Wall class is not a voltage class. A thick general-purpose sleeve is still not a medium-voltage product: voltage duty comes from a tested accessory system. Compare wall classes only within one product family.
Verified pages → MPG35 heavy-wall casing · MPG10 casing
Dielectric insulation
Definition. The recovered wall insulates a live part from its surroundings; it is specified either as voltage withstanding of the tube alone or as the class of a full accessory system.
What must be tested. For tubing: dielectric withstanding on the stated wall. For accessory kits: the complete system, that is, stress control, insulation layers and seals, against the cable class, per the governing standard (IEC 60502 for our kit ranges).
Limit. The two are not interchangeable. A tube's datasheet kV figure never qualifies it as a termination or joint; that qualification belongs to the tested system. This is the most commonly abused shortcut in tubing procurement.
Verified pages → 0.6/1 kV kits · 8.7/15 kV kits · 26/35 kV kits · stress control tube
Frequently asked questions
Is halogen-free the same as flame-retardant?
No. Halogen-free describes what the compound does not contain; flame-retardant describes a tested behavior against a specific method such as UL 224 or VW-1. A compound can be one without the other. Our published halogen-free ranges - the DRS range and the FR 2:1 range - are both, but that is a property of those specific grades, verified by their test reports, not a rule about the words.
Why can't I compare dielectric strength values between two datasheets directly?
Because the number depends on wall thickness and test method. Dielectric strength is measured on a stated wall at a stated condition, so a thin-wall tube and a heavy-wall tube can carry the same material with different volts-per-millimetre results - and different absolute withstanding. Compare values only at matched wall and method, and treat the absolute kV withstanding as the number that matters for your position.
What evidence should I ask for behind a performance claim?
Three things: the test method and standard number (for example UL 224, VW-1, ASTM D2671), the grade or part number the result belongs to, and whether the report was issued against your batch. Generic statements - chemical resistant, high temperature, reliable - are not evidence. If a datasheet cannot tie a claim to a method and a part number, treat the claim as unverified until a report is supplied.