Heat shrink · thin wall
Thin wall tube: GLC 8.0/4.0 to 100/50.0, wall 0.56 to 1.17 mm
2:1, insulation to 3.3 kV, 0.56 mm of recovered wall at the small end and 1.27 mm at GLC 80.0/40.0 — not at the largest code. Seventeen codes below.
GLC thin wall heat shrink tube
GLC is the plain grade — cross-linked polyolefin, 2:1, black only, insulation to 3.3 kV, and no flammability row anywhere on its sheet. GSC is the flame-retardant grade on the same geometry: from 6.0/3.0 upward the two charts carry identical supplied IDs, recovered IDs and walls to two decimals, and identical box counts. One packing figure separates them. At 6.0/3.0 the published GSC sheet prints a 200 m spool where GLC prints 100 m, and a second GSC issue prints 100 m and agrees. GSC also opens seven codes lower, at GSC 1.0/0.5 with a 0.28 mm wall.
- Cross-linked polyolefin, halogen free
- Resistant to chemicals, copper corrosion and fungus
- UV stabilised
- RoHS and REACH compliant
| Shrink ratio | 2:1 |
|---|---|
| Insulation rating | Up to 3.3 kV |
| Size range | GLC 6.0/3.0 to GLC 100/50.0 |
| Recovered wall | 0.56 to 1.27 mm, ±10% |
| Operating temperature | −55 to +125 °C |
| Dielectric strength | >15 kV/mm |
| Standard colour | Black |
| Packing | 25 to 100 m spools; 1.2 m cut lengths, 5 to 200 per box |
GLC selection chart
| Part number / size | Supplied ID mm (min.) | Recovered ID mm (max.) | Recovered wall mm (±10%) | Spool m | Cut lengths 1.2 m / box |
|---|---|---|---|---|---|
| GLC 6.0/3.0 | 6.0 | 3.0 | 0.56 | 100 | 200 |
| GLC 7.0/3.5 | 7.0 | 3.5 | 0.56 | 100 | 200 |
| GLC 8.0/4.0 | 8.0 | 4.0 | 0.56 | 100 | 175 |
| GLC 10.0/5.0 | 10.0 | 5.0 | 0.56 | 100 | 150 |
| GLC 12.7/6.35 | 12.7 | 6.35 | 0.56 | 100 | 120 |
| GLC 14.0/7.0 | 14.0 | 7.0 | 0.69 | 100 | 100 |
| GLC 16.0/8.0 | 16.0 | 8.0 | 0.69 | 100 | 100 |
| GLC 18.0/9.0 | 18.0 | 9.0 | 0.69 | 100 | 80 |
| GLC 20.0/10.0 | 20.0 | 10.0 | 0.78 | 100 | 65 |
| GLC 25.0/12.5 | 25.0 | 12.5 | 0.78 | 50 | 40 |
| GLC 30.0/15.0 | 30.0 | 15.0 | 0.87 | 50 | 30 |
| GLC 40.0/20.0 | 40.0 | 20.0 | 0.97 | 50 | 20 |
| GLC 50.0/25.0 | 50.0 | 25.0 | 0.97 | 25 | 15 |
| GLC 60.0/30.0 | 60.0 | 30.0 | 0.96 | 25 | 10 |
| GLC 70.0/35.0 | 70.0 | 35.0 | 1.10 | 25 | 10 |
| GLC 80.0/40.0 | 80.0 | 40.0 | 1.27 | 25 | 10 |
| GLC 100/50.0 | 100.0 | 50.0 | 1.17 | 25 | 5 |
Reproduced from the manufacturer's GLC-only sheet, which opens two codes below this page's headline range. Supplied ID is a minimum and recovered ID a maximum, so a code passes over anything up to its supplied figure and grips down to its recovered one. The thin wall PDF the manufacturer publishes is the GSC flame-retardant sheet, which carries this same chart from 6.0/3.0 up. Every other series stocked against a diameter sits on the heat shrink size chart.
The wall column is a free-recovery figure
Every wall above is measured with the tube shrunk onto nothing. Put GLC 40.0/20.0 over a 28 mm conductor and it halts 8 mm above the 20.0 mm it was measured at. It has spent 12 of its 20 mm of travel. The rest of the thickening never happens, and the wall on the job is under 0.97 mm.
No thin wall sheet carries a wall-against-diameter curve, so there is no intermediate figure to read off. What follows is a buying rule: take the smallest code whose supplied ID still passes over the part with its lug or connector fitted. That code delivers a wall closest to its printed one.
Nor does the wall climb evenly. It holds at 0.56 mm for five codes, 6.0/3.0 through 12.7/6.35, then steps to 0.69, 0.78, 0.87 and 0.97, dips to 0.96 at 60.0/30.0, and resumes at 1.10. The largest single step is 12.7/6.35 to 14.0/7.0: the bore grows 1.3 mm and the wall grows 23 per cent. A mechanical or dielectric margin that depends on wall is bought there.
GLC 80.0/40.0 is the thickest row, not GLC 100/50.0
70.0/35.0 gives 1.10 mm, 80.0/40.0 gives 1.27 mm, and the largest code drops back to 1.17 mm. Three sheets print it that way — GLC's own, the GSC flame-retardant sheet and the manufacturer's busbar master sheet — so it is published, not a transcription slip. If you are buying the top code for its wall rather than its bore, confirm the figure against your production lot before ordering.
Physical properties, GLC
| Property | Value | Method |
|---|---|---|
| Tensile strength | 10 N/mm² (min.) | ASTM D638 |
| Ultimate elongation | 200% (min.) | ASTM D638 |
| Water absorption | 0.15% (max.) | ASTM D570 |
| Longitudinal change | −10% (max.) | ASTM D638 |
Thermal properties, GLC
| Property | Value | Method |
|---|---|---|
| Operating temperature | −55 to +125 °C | IEC 216 |
| Low temperature flexibility, −55 °C for 4 h | No cracking | ASTM D2671 |
Electrical properties, GLC
| Property | Value | Method |
|---|---|---|
| Dielectric strength | >15 kV/mm | ASTM D2671 |
| Dielectric constant | 5.0 (max.) | ASTM D150 |
| Volume resistivity | 1 × 10¹⁴ Ohm·cm (min.) | ASTM D257 |
Dielectric strength is quoted per millimetre of wall, so the thinnest codes carry the least absolute withstand — and a tube stopped short of free recovery carries less again. What each of these methods tests is set out on the standards page.
GLC, GSC, GSC/YG, GLC3 — and GSC 3X
One geometry, five sheets. Flammability, colour, ratio and voltage are what move.
- GLC — the base grade. 2:1, black only, 3.3 kV, dielectric strength >15 kV/mm. Its sheet carries no flammability row at all, so do not read a flame-retardant grade into it on a panel that specifies one.
- GSC — halogen free, flame retardant and self-extinguishing, on the identical chart from 6.0/3.0 up. UL 224 VW-1, MIL-I-23053/5 Class 2 and 3, CSA C22.2. Dielectric strength >20 kV/mm. Seven standard colours against GLC's black, and seven codes below where GLC starts, down to GSC 1.0/0.5 for terminal, pin and component work.
- GSC/YG — GSC carrying a dual yellow and green stripe along the tube, so an earth lead reads as an earth lead at a glance in a crowded gland plate. The suffix is the whole difference; dimensions and properties are GSC's.
- GLC3 — 3:1, 600 V, specified by the manufacturer for tunnels and mines. Eight codes, and a one-sided wall tolerance of +0.10 or +0.20 mm where GLC and GSC are ±10%. Tensile 14 N/mm² and dielectric strength >20 kV/mm, both above GLC's, on a part rated for a fifth of the voltage.
- GSC 3X — the other 3:1 thin wall, on its own sheet issued December 2025: flame retardant, 3.3 kV rather than 600 V, seventeen codes from 1.5/0.5 to 100.0/33.0, walls 0.45 to 2.60 mm. Where its codes overlap GLC3's the walls agree except at 39.0/13.0, which is 1.50 mm on GSC 3X and 1.15 mm on GLC3. The prefix is load-bearing.
GLC3 selection chart, 3:1
| Part number / size | Supplied ID mm | Recovered ID mm | Recovered wall mm | Spool m | Cut lengths 1.2 m / box |
|---|---|---|---|---|---|
| GLC3-1.5/0.5 | 1.5 | 0.5 | 0.45 +0.10 | 200 | 1000 |
| GLC3-3.0/1.0 | 3.0 | 1.0 | 0.55 +0.10 | 200 | 500 |
| GLC3-6.0/2.0 | 6.0 | 2.0 | 0.65 +0.10 | 50 | 200 |
| GLC3-9.0/3.0 | 9.0 | 3.0 | 0.75 +0.20 | 50 | 150 |
| GLC3-12.0/4.0 | 12.0 | 4.0 | 0.75 +0.20 | 50 | 120 |
| GLC3-18.0/6.0 | 18.0 | 6.0 | 0.85 +0.10 | 50 | 80 |
| GLC3-24.0/8.0 | 24.0 | 8.0 | 1.00 +0.20 | 50 | 40 |
| GLC3-39.0/13.0 | 39.0 | 13.0 | 1.15 +0.20 | 25 | 20 |
Wall tolerance is plus-only here, so a GLC3 wall never lands under its stated figure. The chart is published on the manufacturer's combined thin wall sheet, alongside GSC and GDW. Read the ratio in the codes: GLC3-39.0/13.0 closes a 39 mm bore onto 13 mm, which nothing in the GLC chart above can do. What a ratio does and does not promise is on shrink ratio explained.
Three published GSC sheets do not agree with each other
Get the GSC figure you are relying on confirmed in writing. The thin wall PDF linked above gives tensile strength 9 N/mm² minimum and volume resistivity 1 × 10¹³ Ohm·cm. A second issue of the same sheet gives 16 N/mm² and 1 × 10¹⁴. The combined sheet also gives 16 N/mm², but rates GSC to 600 volts rather than 3.3 kV, and its chart drops the 60/30, 70/35 and 80/40 rows while adding GSC 3.5/1.7, 9.0/4.5, 12.0/6.0, 22.0/11.0 and 76.0/38.0. They split on the UL file number too: two print E328193 and one prints E328538. E328538 is the number in the manufacturer's own UL listing history, so here the two agreeing sheets are the doubtful ones.
If the part is a busbar, this is the wrong chart
The GLC sheet lists bus-bar insulation for switchgear and rates the tube to 3.3 kV. Both are true, and neither is enough to order from, because a rectangular bar is not sized on internal diameter. The manufacturer sizes it on width plus breadth for rectangular bar and on a diameter band for round, and publishes a separate chart against those columns. On that chart GSC 100/50 carries a 1.40 mm recovered wall to a +5%/−2% tolerance, against 1.17 mm and ±10% here, and three more rows differ by 0.01 mm. Read the sheet written for the geometry in front of you: the same manufacturer's busbar reference in this network is busbarsleeves.com.
Where to go from a thin wall code
- Heat shrink size chartEvery series this site covers, on one diameter axis
- Medium and heavy wall tubeWhere 3.3 kV runs out: GMW, then GHW at 36 kV to IEC 60684-3-247
- High shrink ratio tubeWhen a 2:1 bore cannot pass the connector and still grip the cable
- Why shrink tube failsUndersized recovery is the thin wall entry point
- Wire harness tubingBundling, strain relief and identification with these grades
- All heat shrink gradesThe hub above this page
Have a diameter and no code yet?
Four figures pick it: the diameter over the widest obstruction, the diameter it has to grip, the voltage, and whether the site demands a flame-retardant grade. With those, GLC, GSC and GLC3 separate without a second email.