Heat Shrink Co-Extruded Tubing (GMWR/GHWR)
GMWR and GHWR are premium-quality co-extruded medium-wall and heavy-wall heat shrink tubing, combining a high shrink ratio with hot-melt adhesive lining for waterproof sealing.
- ASTM D638
- ASTM D570
- ASTM D792
Choose a size
Selection Charts
- D min.
- Minimum internal diameter as supplied
- d max.
- Maximum internal diameter after recovery
- T
- Recovered wall thickness (±10 %)
| Code | D min.(mm) | d max.(mm) | T ±10%(mm) |
|---|---|---|---|
| GMWR 12/3 | 12 | 3 | 1.5 |
| GMWR 22/6 | 22 | 6 | 2.0 |
| GMWR 30/8 | 30 | 8 | 2.5 |
| GMWR 33/10 | 33 | 10 | 2.5 |
| GMWR 40/12 | 40 | 12 | 2.5 |
| GMWR 50/16 | 50 | 16 | 2.5 |
| GMWR 65/19 | 65 | 19 | 2.5 |
| GMWR 70/22 | 70 | 22 | 2.5 |
| GMWR 90/28 | 90 | 28 | 3.0 |
| GMWR 130/36 | 130 | 36 | 3.0 |
Hot-melt adhesive lining available up to GMWR 50/16 and GHWR 50/16. Order as code, size, A (with adhesive) and length in mm, e.g. GMWR 12/3 A 1000. Source: GALA Heat Shrink Flame Retardant Tubing (GMWR / GHWR) catalogue sheet, Issue 2, April 2026.
GHWR heavy wall selection chart
| Code | D min.(mm) | d max.(mm) | T ±10%(mm) |
|---|---|---|---|
| GHWR 12/3 | 12 | 3 | 2.2 |
| GHWR 22/6 | 22 | 6 | 2.5 |
| GHWR 30/8 | 30 | 8 | 3.0 |
| GHWR 33/10 | 33 | 10 | 4.0 |
| GHWR 40/12 | 40 | 12 | 4.0 |
| GHWR 50/16 | 50 | 16 | 4.0 |
| GHWR 65/19 | 65 | 19 | 4.0 |
| GHWR 70/22 | 70 | 22 | 4.0 |
| GHWR 90/28 | 90 | 28 | 4.0 |
| GHWR 130/36 | 130 | 36 | 4.0 |
Hot-melt adhesive lining available up to GMWR 50/16 and GHWR 50/16. Order as code, size, A (with adhesive) and length in mm, e.g. GMWR 12/3 A 1000. Source: GALA Heat Shrink Flame Retardant Tubing (GMWR / GHWR) catalogue sheet, Issue 2, April 2026.
Material properties
Technical Specification
| Properties | Value | Standard |
|---|---|---|
| Physical | ||
| Tensile Strength | 9 N/mm² (MPA)(min.) | ASTM D638 |
| Ultimate Elongation | 300 % (min.) | ASTM D638 |
| Water absorption | 0.15 % (max.) | ASTM D570 |
| Specific Gravity | 1.4 | ASTM D792 |
| Longitudinal Change | -10 % (max.) | ASTM D638 |
| Thermal | ||
| Operating Temp. (Outer Wall) | -55 to +125 °C | IEC 216 |
| Heat Shock (250 °C for 4 hrs.) | No dripping, cracking or flowing (Outer Wall) | |
| Chemical | ||
| Fungus Resistance | Inert | MIL-1-7444 |
| Copper Corrosion | Good | ASTM D2671B |
| Chemical Resistance | Good | ASTM D2671 |
| Electrical | ||
| Dielectric Strength | 15 KV/mm. (Min.) | ASTM D2671 |
| Dielectric Constant | 3.0 (Max.) | ASTM D150 |
| Volume Resistivity | 1 × 10¹³ Ohm.cm(min.) | ASTM D257 |
Dimensions & Drawings
GMWR (medium wall) and GHWR (heavy wall) are co-extruded premium-quality heat shrink tubing, used as waterproof sealing on cable terminations and joints, and for corrosion protection, environmental sealing and mechanical protection of pipes and pipe connections. Also used for insulating underground and aerial CATV plant connections, CCTV connections and control-cable splicing joints.
Tubing with a hot-melt adhesive lining provides waterproofing and environmental sealing. Technical Qualification Report: QR 1014.
Covered on this page
- Heat Shrinkable Tubes/Heat Shrink Sleeves
- HEAT SHRINK CO-EXTRUDED TUBING PREMIUM QUALITY
- GENERAL PROPERTIES :
Features & Benefits
- High shrink ratio via co-extrusion technology
- Soft and flexible
- Fast, uniform shrinking
- High resistance to decay, chemicals, copper corrosion and UV rays
- Hot melt adhesive lining provides waterproofing and environmental sealing
- Standard colour black; other colours on request
Applications
- Medium and heavy wall cable/pipe protection
- Waterproof environmental sealing over splices and joints
Standards & Compliance
- ASTM D638
- ASTM D570
- ASTM D792
- ASTM D2671
- ASTM D2671B
- ASTM D150
- ASTM D257
- IEC 216
- MIL-I-7444
FAQs
Frequently Asked Questions
What is the Heat Shrink Co-Extruded Tubing used for?
It is used for:
- Medium and heavy wall cable/pipe protection
- Waterproof environmental sealing over splices and joints
How do I choose the right size?
A heat-shrink part is chosen by two diameters. As supplied (D min. (mm)) it must open wider than the largest thing it has to slide over; after shrinking (d max. (mm)) it must close smaller than the smallest thing it has to grip. Measure both on your cable or busbar and pick the first code in the selection chart that satisfies both.
How is it installed?
Clean and degrease the surface, position the part, then shrink it with a gas torch or a hot-air gun: keep the heat moving round it with a smooth, brushing motion so it recovers evenly without scorching. Start at one end and work steadily along to the other.
Which standards and test methods are quoted for it?
These, with the values in the Technical Specification on this page:
- ASTM D638
- ASTM D570
- ASTM D792
- ASTM D2671
- ASTM D2671B
- ASTM D150
- ASTM D257
- IEC 216
- MIL-I-7444
Where can I download the datasheet?
From the "Download datasheet" button at the top of this page, or here:
Can I get a quote, a sample or a size that is not listed?
Send your cable details, quantity and application with the "Request a Quote or Sample" form at the foot of this page. For a size or variant that is not in the chart, describe what you need there, or use Technical support at the top of the page, and the technical team will confirm what can be supplied.
47+
Years manufacturing
100+
Countries served
140
Products in range
ISO 9001:2015
Certified & tested