Harness Protection · MPN-Led Sourcing
DR-25 Heat-Shrink Tubing for Harness Protection
DR-25 is a heat-shrinkable elastomeric sleeve used to jacket and protect wiring harnesses in demanding aerospace, defence and marine environments. This guide explains how to specify it correctly — and how to package that specification into a structured RFQ so quotations come back against the right part, not an approximation.
Submit an RFQ Interconnect capabilityWhat DR-25 is, and why harness engineers reach for it
DR-25 is a family designation for a radiation-crosslinked, flexible heat-shrink tubing originally developed by Raychem and widely specified across the aerospace and defence industry. Unlike rigid polyolefin shrink sleeving, DR-25 stays supple after recovery, which matters when a harness has to flex, route around structure and survive vibration over a long service life. It is most often used as an outer jacket over the harness bundle — a continuous, abrasion- and fluid-resistant skin that also provides a clean surface for identification.
Because it is qualified against recognised performance standards rather than sold as a generic sleeve, DR-25 is treated as a controlled item in most build-of-materials. That makes the manufacturer part number the unit of procurement: the same nominal size can differ by wall construction, colour, adhesive lining and qualification, and those differences are not interchangeable. Getting the MPN right at RFQ time is what keeps a harness build conforming to its drawing.
Properties that drive the selection
Four characteristics tend to govern whether DR-25 is the right protection for a given harness, and which variant within the family applies.
Withstands aggressive fluids
Engineered to resist common aerospace and industrial fluids — fuels, hydraulic oils, lubricants and many solvents — making it suitable where a harness is exposed to fluid contact or vapour.
Wide service range
Rated for sustained operation across a broad temperature band typical of avionics bays and engine-adjacent routing. Confirm the exact range against the specific part's datasheet for the variant quoted.
Flexible after recovery
Remains elastic once shrunk, so the jacketed bundle keeps its bend radius and resists cracking under flex and vibration — a key reason it is preferred over rigid sleeving.
Abrasion & environmental skin
Provides mechanical abrasion resistance and a sealed outer surface. Dual-wall variants add an internal adhesive that bonds and environmentally seals at terminations and breakouts.
Single-wall vs dual-wall, and what shrink ratio means for sizing
Single-wall DR-25 is the standard harness jacket: one homogeneous elastomeric layer that recovers tightly around the bundle for abrasion and fluid protection. Dual-wall versions add a meltable adhesive inner layer that flows on heating to bond the tubing and form an environmental seal — used at connector backshells, breakouts and transitions where moisture ingress must be stopped. Specify dual-wall only where sealing is required; it is not a drop-in substitute for the single-wall jacket on a drawing that calls out single-wall.
The shrink ratio (commonly around 2:1 for this family) tells you how far the tubing recovers from its supplied diameter. Correct sizing requires both numbers: the expanded (as-supplied) inner diameter must slide over the largest point of the bundle — typically a connector or breakout — and the recovered diameter must close down tightly onto the smallest point. A part that recovers but cannot pass the connector is as wrong as one that passes but never grips. When you raise an RFQ, give the bundle's maximum and minimum diameters so the size can be verified against the recovered dimension, not guessed.
DR-25 selection reference
A planning aid for matching application to variant. Always confirm exact dimensions, ratings and qualification against the specific part number's published datasheet before release.
| Variant type | Wall | Primary function | Typical use point | Specify when… |
|---|---|---|---|---|
| Standard jacket | Single | Abrasion & fluid-resistant harness skin | Main bundle runs | Drawing calls out a flexible outer jacket without sealing |
| Sealed / adhesive-lined | Dual | Bonds and environmentally seals | Backshells, breakouts, transitions | Moisture ingress or strain relief must be controlled |
| Identification grade | Single | Markable surface for harness ID | Bundles needing printed marker callout | Drawing requires legible, durable identification |
| Moulded / boots & shapes | Varies | Shaped transition & strain relief | Branch-outs, connector exits | A geometry change needs a pre-formed part, not straight tube |
Marker and identification considerations
On controlled harnesses the jacket is often also the identification carrier. DR-25 surfaces can be printed or over-sleeved with identification markers, but the marking method, legend content and durability requirements are usually fixed by the harness drawing and the applicable wiring standard. When identification is in scope, an RFQ should state whether you need plain tubing, a markable grade, or pre-printed marker sleeves — and any legend, colour or standard the marking must satisfy. Treating identification as part of the part definition, rather than a downstream step, avoids re-quoting and keeps the as-built harness traceable to its drawing.
Where this sits in our sourcing
DR-25 rarely arrives on an RFQ alone — it comes with connectors, contacts, backshells and the rest of the harness protection stack. These are the capability areas most relevant to a harness-protection enquiry.
Avionics, Electronics & Interconnect
Connectors, contacts, harness protection and interconnect hardware sourced by manufacturer part number.
View capability → FamilyCircular Connectors
The connector side of the harness — the backshells and exits where dual-wall DR-25 typically seals.
Explore connectors → PillarUAV / UAS Mission Support
Lightweight, flexible harness protection for unmanned platforms where mass and routing are constrained.
View capability → PillarMRO, Tools & Workshop
Heat guns, reflectors and processing consumables that support correct DR-25 recovery on the bench.
View capability →From part number to documented quotation
A clean RFQ shortens the path to a usable quotation. Here is how a harness-protection enquiry typically moves through our process.
Submit the MPN or BOM
Send the DR-25 part number, or a bill of materials with bundle diameters and any marking callout, through the RFQ form.
Specification check
We confirm wall construction, size against recovered diameter, colour, sealing and identification needs so the quotation matches the drawing.
Structured quotation
You receive a documentation-led quotation built around the verified part — with export-aware coordination noted where the destination requires it.
Cross-border coordination
For buyers across the UAE, Saudi Arabia and Australia, we handle the enquiry with the destination market and its documentation in view.
Frequently asked questions
What is DR-25 heat-shrink tubing used for?
DR-25 is a flexible, fluid- and abrasion-resistant heat-shrink tubing used primarily as an outer jacket over wiring harnesses in aerospace, defence, marine and demanding industrial applications. It protects the bundle mechanically and environmentally while remaining flexible after it has recovered around the wires.
What is the difference between single-wall and dual-wall DR-25?
Single-wall DR-25 is a single elastomeric layer that recovers tightly around a bundle to provide an abrasion- and fluid-resistant jacket. Dual-wall versions add an inner adhesive that melts during recovery to bond the tubing and form an environmental seal, which is why dual-wall is chosen at backshells, breakouts and other points where moisture must be sealed out. They are not interchangeable — specify whichever the drawing calls out.
What shrink ratio does DR-25 have, and how do I size it?
DR-25 in this family is commonly supplied with an approximately 2:1 shrink ratio, meaning it recovers to roughly half its expanded diameter. To size it, the as-supplied inner diameter must slide over the largest point of the bundle (often a connector), and the recovered diameter must close down onto the smallest point. Provide both the maximum and minimum bundle diameters so the size can be checked against the recovered dimension rather than estimated.
Is DR-25 fluid resistant?
Yes. DR-25 is engineered to resist common aerospace and industrial fluids including fuels, hydraulic fluids, lubricants and many solvents, which is a central reason it is specified for harness protection in fluid-exposed routing. The exact resistance and temperature ratings should be confirmed against the published datasheet for the specific part number being quoted.
Can DR-25 be marked for harness identification?
DR-25 surfaces can be printed or over-sleeved with identification markers, and identification-grade tubing or pre-printed marker sleeves are available. The marking method, legend and durability are normally fixed by the harness drawing and the relevant wiring standard, so it is best to state your identification requirement at RFQ time so it is quoted as part of the part definition.
Can BOLTON supply DR-25 against a specific part number?
BOLTON is an MPN-led technical sourcing company headquartered in Abu Dhabi, supporting procurement teams across the UAE, Saudi Arabia and Australia. Submit the DR-25 part number or your harness bill of materials through the RFQ form and we return a structured, documentation-led quotation. We do not publish stock levels or live pricing; each enquiry is quoted on its own through the RFQ process.
Decode the part number. Protect the specification.
Send us the DR-25 callout or the full harness BOM. We will verify the variant, wall and recovered size against your requirement and return a structured quotation built for traceability.
Request a DR-25 quotation Talk to sourcingManufacturer and product names — including DR-25 and Raychem — are referenced for identification purposes only to describe the items a buyer may request. Their use does not imply that BOLTON is an authorised distributor, official partner, agent or approved vendor of any manufacturer, nor any endorsement or affiliation. Technical figures are nominal and indicative; confirm all dimensions, ratings and qualification against the specific part number's current published datasheet before release.