GMW 5x
5:1 tube: covering a connector and its cable in one size
Eleven sizes, 30/6 to 160/32. At the 160 mm supplied bore where GMW and GHW both stop at 50 mm, GMW 5x keeps recovering to 32 — and finishes with a 5.0 mm wall. Read it as a heavy-wall part that carries a high ratio, not as a thin one.
GMW 5x high shrink ratio tube
Cross-linked polyolefin at a shrink ratio up to 5:1, sized to cover the transition from a cable to its connector and back shell in one piece, and to seal the back end of a connector. Recovered wall runs 4.3 to 5.0 mm across the whole range. Made by Gala Thermo Shrink Pvt. Ltd. at Palghar, Maharashtra; this site publishes the charts and manufactures nothing.
- High shrink ratio up to 5:1
- Optional hot-melt adhesive lining for complete environmental protection and insulation
- Meets IP 68 ingress protection
- Resistance to weathering, UV rays, chemicals and solvents
- RoHS compliant and halogen free
| Shrink ratio | Up to 5:1 |
|---|---|
| Sizes | Eleven, GMW 5x 30/6 to GMW 5x 160/32 |
| Recovered wall | 4.3 to 5.0 mm, tolerance ±10% |
| Shrink temperature | 125°C |
| Continuous temperature limit | −40 to +110°C |
| Dielectric strength | 12 kV/mm min. on a 2 mm wall |
| Material | Cross-linked polyolefin |
| Ingress protection | Meets IP 68 |
| Qualification report | QR 1013 |
GMW 5x selection chart
| Product code | D min. as supplied (mm) | d max. recovered (mm) | Recovered wall T ±10% (mm) |
|---|---|---|---|
| GMW 5x 30/6 | 30 | 6 | 4.3 |
| GMW 5x 40/8 | 40 | 8 | 4.3 |
| GMW 5x 50/10 | 50 | 10 | 4.3 |
| GMW 5x 60/12 | 60 | 12 | 4.5 |
| GMW 5x 75/15 | 75 | 15 | 4.5 |
| GMW 5x 90/18 | 90 | 18 | 4.5 |
| GMW 5x 105/21 | 105 | 21 | 5.0 |
| GMW 5x 115/23 | 115 | 23 | 5.0 |
| GMW 5x 130/26 | 130 | 26 | 5.0 |
| GMW 5x 140/28 | 140 | 28 | 5.0 |
| GMW 5x 160/32 | 160 | 32 | 5.0 |
D is the smallest bore you get as supplied, so it has to clear the largest thing the tube passes over. d is the largest bore left after full recovery, so it has to sit under the smallest diameter the tube must grip. Wall carries ±10%. Reproduced from the datasheet, Issue 1, July 2024; these eleven sizes also sit in the full heat shrink size chart.
Same supplied bore, three recovered bores
| Supplied bore D (mm) | GMW 5x recovers to (mm) | GMW recovers to (mm) | GHW recovers to (mm) |
|---|---|---|---|
| 30 | 6 | 8 | 8 |
| 40 | 8 | 12 | 12 |
| 50 | 10 | 16 | 16 |
| 75 | 15 | 22 | 22 |
| 105 | 21 | 30 | 30 |
| 115 | 23 | 34 | 34 |
| 130 | 26 | 36 | 36 |
| 140 | 28 | 42 | 42 |
| 160 | 32 | 50 | 50 |
Nine of the eleven GMW 5x sizes are supplied at exactly the D of a GMW and GHW size, so the charts read straight against each other: same starting bore, different finishing bore. The extra recovery is paid for in wall. At 160 mm supplied, the recovered wall is 3.3 mm on GMW, 4.3 mm on GHW and 5.0 mm on GMW 5x. GMW 5x 60/12 and 90/18 have no matching GMW or GHW entry and are left out here.
Technical specification
| Property | Value | Test method |
|---|---|---|
| Tensile strength | 12 N/mm² (MPa) min. | ASTM D638 |
| Ultimate elongation | 350% min. | ASTM D638 |
| Density | 1.0 ± 0.2 gm/cm³ | ASTM D792 |
| Longitudinal change | −10% max. | ASTM D2671 |
| Hardness | 45 ± 10 Shore D | ASTM D2240 |
| Water absorption | 0.5% max. | ASTM D570 |
| Accelerated ageing | 150°C for 168 hrs. | ASTM D2671 |
| Tensile strength after ageing | 10 N/mm² (MPa) min. | ASTM D638 |
| Ultimate elongation after ageing | 300% min. | ASTM D638 |
| Low temperature flexibility, −40°C for 4 hrs. | No cracking | ASTM D2671 |
| Heat shock, 250°C for 30 min. | No cracking or flowing | ESI 09-11 |
| Shrink temperature | 125°C | IEC 216 |
| Continuous temperature limit | −40 to +110°C | IEC 216 |
| Dielectric strength, 2 mm wall | 12 kV/mm min. | ASTM D149 |
| Volume resistivity | 1 × 10¹² Ohm.cm min. | ASTM D257 |
| Dielectric constant | 5 max. | ASTM D150 |
Every value in this table is printed identically on the GMW and GHW medium and heavy wall datasheet, and both sheets carry Technical Qualification Report QR 1013 — the compound is not what the ratio changes, the chart above is. Note the 15°C between the +110°C service ceiling and the 125°C shrink point. The weathering line appears on the GMW 5x sheet in these words: the material from which Medium and Heavy wall tubings are manufactured contains carbon black to protect it from UV light. Neither sheet prints exposure hours, so ask the manufacturer if your specification wants a number.
Why one 5:1 size beats stepping down through two
Put a 28 mm connector body and an 8 mm cable under one tube and the two charts settle it before any preference does. GMW 5x 30/6 passes over the 28 mm body and carries on down to 6 mm, which is under the cable, so the tube closes on it. GMW 30/8 starts at the same 30 mm and stops at 8 mm — the cable's own diameter, with nothing left to grip with. A 2:1 tube supplied at 30 mm stops at 15 mm by definition, standing 3.5 mm clear of that cable on every side.
The alternative is two tubes and a step-down, which puts a lap joint exactly at the diameter change. One part number removes the joint. That is the whole argument for a high ratio, and it is a geometry argument: the compound is the same one the 3:1 parts are made from.
The ratio is paid for in wall and in time. GMW 5x finishes with 4.3 to 5.0 mm on it against 2.6 mm for GMW 30/8, so there is far more polymer between the gun and the bore, and the outer skin reaches the 125°C shrink point well before the inner surface has moved. Keep the gun back, work along the axis from one end, keep the tube turning, and give a 160/32 several times what a thin wall needs. Stroke order is on installing heat shrink tube; the faults that follow from rushing it are on why a recovered tube fails.
Two limits are worth stating plainly. GMW 5x carries no voltage class on its own datasheet: 12 kV/mm is a material property measured on a 2 mm wall, not a rating for a joint, and the rated parts are GMW at 3.3 kV and GHW at 36 kV. And a 5:1 tube still recovers as a cylinder, so where the transition branches instead of stepping, the ratio does not help — that is tube or moulded shape.
The lined code is not printed on this sheet
Ordering information on the GMW 5x sheet reads GMW 5x 30/6 U 1000, keyed as Gala code, size, without adhesive, length in mm. U is the only suffix printed and no cut lengths are given. The feature list does offer a hot-melt lining as an option, and the co-extruded GMWR sheet uses A in the same position — GMWR 10/3 A 1000, keyed with adhesive — but the lined GMW 5x code itself appears nowhere on its own datasheet. The 1200 mm maximum cut length belongs to the GMW/GHW series and does not transfer. Confirm the suffix and the available length before you raise a part number, and see what each sheet actually certifies before you quote one into a specification.
Lower ratios, and where each one wins
5:1 answers one problem. If your largest and smallest diameters sit closer than about four to one, a lower ratio gives you a thinner wall, a faster recovery and, in two of these three, a stated voltage.
- GMW and GHW at 3:1 — the rated partsGMW insulates connectors on low-voltage terminations and straight joints to 3.3 kV; GHW mechanically protects and outer-seals buried straight joints to 36 kV. Conforms to IEC 60684-3-247. Same compound and the same QR 1013 as GMW 5x, with a 1200 mm maximum cut length.
- GDW dual wall at 3:1 and 4:1For the same transition when the hot-melt seal is the product rather than an option: polyolefin co-extruded over adhesive, −55°C to +125°C, GDW 3/1 to GDW 50/17, plus GDWH-1 to GDWH-5 for the 4:1 harness sizes.
- GLC3 thin wall at 3:1, to 600 VBuilt for critical areas such as tunnels and mines. Thin wall, so it insulates and takes abrasion without the bulk a 5 mm recovered wall brings.
- What 2:1, 3:1, 4:1 and 5:1 actually buyThe ratio arithmetic on its own, with no part number attached to it.
- Every wall grade and ratio in one indexThe hub, ordered by recovered diameter.
Send the span, not two part numbers
Three figures fix the size: the largest diameter the tube must pass over, the smallest it must grip, and the length of the transition between them. Add whether the lining is needed and whether the assembly ends up buried or exposed, and the reply comes back as a code rather than as a question.