Read a heat shrink tubing size chart using two inside diameters: the expanded bore before heating and the freely recovered bore after shrinking. The supplied bore must clear the largest feature; the recovered bore must be smaller than the surface it needs to grip. Use the actual row limits, rather than dividing a nominal size by the shrink ratio.
The charts below reproduce 61 size entries across three YOCL series. All dimensions are in millimetres. They are series-specific product declarations, not a universal chart for every heat-shrink material.
YOCL heat shrink tubing size charts
Approximately 2:1 single-wall tubing — HTS
The YOCL HTS dimension table gives paired nominal sizes and before/after-shrink fields with ± tolerances. Keep those tolerances when reading a size such as 12.0/6.0; the pair does not mean both diameters are exact.
| Nominal size pair (mm) | Before-shrink ID (mm) | After-shrink field† (mm) |
|---|---|---|
| 1.0/0.5 | 1.0 ± 0.3 | 0.5 ± 0.1 |
| 1.5/0.75 | 1.5 ± 0.3 | 0.75 ± 0.1 |
| 2.0/1.0 | 2.0 ± 0.3 | 1.0 ± 0.1 |
| 2.5/1.25 | 2.5 ± 0.3 | 1.25 ± 0.1 |
| 3.0/1.5 | 3.0 ± 0.3 | 1.5 ± 0.1 |
| 3.5/1.75 | 3.5 ± 0.3 | 1.75 ± 0.1 |
| 4.0/2.0 | 4.0 ± 0.3 | 2.0 ± 0.1 |
| 5.0/2.5 | 5.0 ± 0.3 | 2.5 ± 0.2 |
| 6.0/3.0 | 6.0 ± 0.4 | 3.0 ± 0.2 |
| 7.0/3.5 | 7.0 ± 0.4 | 3.5 ± 0.2 |
| 8.0/4.0 | 8.0 ± 0.4 | 4.0 ± 0.2 |
| 9.0/4.5 | 9.0 ± 0.4 | 4.5 ± 0.2 |
| 10.0/5.0 | 10.0 ± 0.4 | 5.0 ± 0.2 |
| 11.0/5.5 | 11.0 ± 0.4 | 5.5 ± 0.2 |
| 12.0/6.0 | 12.0 ± 0.4 | 6.0 ± 0.3 |
| 13.0/6.5 | 13.0 ± 0.4 | 6.5 ± 0.3 |
| 14.0/7.0 | 14.0 ± 0.4 | 7.0 ± 0.3 |
| 15.0/7.5 | 15.0 ± 0.4 | 7.5 ± 0.4 |
| 16.0/8.0 | 16.0 ± 0.5 | 8.0 ± 0.3 |
| 17.0/8.5 | 17.0 ± 0.5 | 8.5 ± 0.3 |
| 18.0/9.0 | 18.0 ± 0.5 | 9.0 ± 0.3 |
| 20.0/10.0 | 20.0 ± 0.5 | 10.0 ± 0.3 |
| 22.0/11.0 | 22.0 ± 0.5 | 11.0 ± 0.3 |
| 25.0/12.5 | 25.0 ± 0.8 | 12.5 ± 1.0 |
| 28.0/14.0 | 28.0 ± 0.8 | 14.0 ± 1.0 |
| 30.0/15.0 | 30.0 ± 0.8 | 15.0 ± 1.0 |
| 35.0/17.5 | 35.0 ± 0.8 | 17.5 ± 1.0 |
| 40.0/20.0 | 40.0 ± 1.5 | 20.0 ± 1.0 |
| 45.0/22.5 | 45.0 ± 1.5 | 22.5 ± 1.0 |
| 50.0/25.0 | 50.0 ± 1.5 | 25.0 ± 1.0 |
| 60.0/30.0 | 60.0 ± 1.5 | 30.0 ± 1.5 |
| 70.0/35.0 | 70.0 ± 1.5 | 35.0 ± 1.5 |
| 80.0/40.0 | 80.0 ± 1.5 | 40.0 ± 1.5 |
| 90.0/45.0 | 90.0 ± 1.5 | 45.0 ± 1.5 |
| 100.0/50.0 | 100.0 ± 1.5 | 50.0 ± 1.5 |
| 120.0/60.0 | 120.0 ± 1.5 | 60.0 ± 1.5 |
| 150.0/75.0 | 150.0 ± 1.5 | 75.0 ± 1.5 |
| 180.0/90.0 | 180.0 ± 1.5 | 90.0 ± 1.5 |
| 200.0/100.0 | 200.0 ± 1.5 | 100.0 ± 1.5 |
† The source heads its after-shrink column “Max. I.D. after shrinking” while listing ± values. Those values are reproduced unchanged here, rather than recast as unqualified maximum limits. Obtain the definitive supplied/recovered limits for the chosen HTS size before approving a fit close to either boundary.
3:1 adhesive-lined tubing — HS3X
The YOCL HS3X dimension table states a minimum supplied ID and maximum recovered ID. Metric entries below retain YOCL’s published values; they are not recalculated from fractional-inch size labels.
| Metric size entry (mm) | Supplied ID (mm), minimum | Recovered ID (mm), maximum |
|---|---|---|
| 2.4 | ≥2.4 | ≤0.8 |
| 3.2 | ≥3.2 | ≤1.0 |
| 4.8 | ≥4.8 | ≤1.6 |
| 6.4 | ≥6.4 | ≤2.2 |
| 7.9 | ≥7.9 | ≤2.7 |
| 9.5 | ≥9.5 | ≤3.2 |
| 12.7 | ≥12.7 | ≤4.2 |
| 15.0 | ≥15.0 | ≤5.2 |
| 19.1 | ≥19.1 | ≤6.3 |
| 25.4 | ≥25.4 | ≤8.5 |
| 30.0 | ≥30.0 | ≤10.2 |
| 39.0 | ≥39.0 | ≤13.5 |
| 50.0 | ≥50.0 | ≤17.0 |
4:1 adhesive-lined tubing — HS4X
The YOCL HS4X dimension table uses supplied/recovered size pairs and explicit ≥/≤ limits. For example, 16.0/4.0 identifies a supplied bore of at least 16.0 mm and a recovered bore of no more than 4.0 mm.
| Metric size entry (mm) | Supplied ID (mm), minimum | Recovered ID (mm), maximum |
|---|---|---|
| 4.0/1.0 | ≥4.0 | ≤1.0 |
| 6.0/1.5 | ≥6.0 | ≤1.5 |
| 8.0/2.0 | ≥8.0 | ≤2.0 |
| 12.0/3.0 | ≥12.0 | ≤3.0 |
| 16.0/4.0 | ≥16.0 | ≤4.0 |
| 20.0/5.0 | ≥20.0 | ≤5.0 |
| 24.0/6.0 | ≥24.0 | ≤6.0 |
| 32.0/8.0 | ≥32.0 | ≤8.0 |
| 52.0/13.0 | ≥52.0 | ≤13.0 |
These tables cover HTS, HS3X and HS4X only. Other single-wall, semi-rigid, busbar or specialized grades need their own dimension tables; a matching ratio does not make their sizes interchangeable.
Expanded, recovered and installed diameters are different states
Inside diameter (ID) measures the bore of the tubing. Outside diameter (OD) measures the cable or component it must surround.
- Expanded/as supplied: the bore available before heating, used for the pass-over check.
- Freely recovered: the bore reached under specified recovery conditions without an internal object restricting contraction.
- Installed: the sleeve conforms around the object. A cable that is larger than the free-recovery bore prevents it reaching that bore.
For the HS4X 12.0/3.0 row, the two catalogue fields are ≥12.0 mm supplied and ≤3.0 mm recovered. Neither field promises that an installed sleeve around a larger cable will have a 3.0 mm bore.
Read the signs as part of the specification: ≥ supplies a lower bound; ≤ supplies an upper bound; ± retains variation around the stated value. Do not erase these signs when copying dimensions into an enquiry.
Also keep the nominal ratio separate. The HS3X 6.4 mm entry lists a recovered limit of ≤2.2 mm, while 6.4 ÷ 3 is approximately 2.13 mm. Replacing 2.2 with that calculation would change the published specification.
For the wider terminology map, see What Is Heat Shrink Tubing? Ratios, Walls and Adhesive Linings.
Use both diameter limits from the same row
For a preliminary check of round parts and open-ended tubing, identify:
- Largest pass-over OD: the widest round feature the unshrunk sleeve must cross, including a connector or joint.
- Smallest covered OD: the narrowest round cable surface onto which the sleeve needs to recover.
Then compare both dimensions with one size row:
Minimum supplied ID > largest pass-over OD
Maximum freely recovered ID < smallest covered OD
NASA’s KSC-E-165 Revision F, §3.8.1.1.1(a) documents this expanded-larger/recovered-smaller relationship for electrical ground-support-equipment fabrication. It supports the dimensional principle, rather than approval of a YOCL assembly.
Equality leaves no dimensional margin. Include component tolerances and the model’s installation allowance; this chart does not prescribe a universal clearance percentage. Flat busbars, irregular connectors and bundles need a geometry review rather than a single round-diameter comparison.
Worked example: a 14 mm feature and a 5 mm cable
Assume the largest round feature is 14 mm OD and the smallest cable jacket is 5 mm OD. These are illustrative inputs, not measurements of a particular installation.
| Series and metric size | Minimum supplied ID | Maximum recovered ID | Supplied minimum >14 mm? | Recovered maximum <5 mm? |
|---|---|---|---|---|
| HS3X 12.7 mm | 12.7 mm | 4.2 mm | Not established | Pass |
| HS3X 15.0 mm | 15.0 mm | 5.2 mm | Pass | Not established |
| HS4X 16.0/4.0 mm | 16.0 mm | 4.0 mm | Pass | Pass |
HS4X 16.0/4.0 passes both dimensional inequalities for these inputs. It remains a candidate requiring application review. The HS3X 12.7 row does not establish clearance over 14 mm. Moving up to HS3X 15.0 establishes that clearance, but its 5.2 mm recovered upper limit does not establish contraction below a 5 mm jacket.
“Not established” does not claim every specimen will fail. It means the published bound is insufficient to assure that check. Choose the nearest listed row that satisfies both requirements with the specified allowance, rather than simply taking the next larger size.
What the diameter chart does not decide
Measure the actual insulated cable OD. American Wire Gauge (AWG) or conductor cross-sectional area does not specify the jacket diameter, and a flattened sleeve’s width is not its inside diameter. A nominal fractional-inch label likewise cannot replace the model’s stated diameter fields.
The installed sleeve also needs enough space and coverage. Check wall thickness with its measurement state, finished outside dimensions and the product’s longitudinal-change information. Do not assume a freely recovered wall value is the wall on a partly recovered cable, or apply the diameter shrink ratio to cut length. Where a wall field is labelled “total”, do not add its adhesive thickness again.
For the liner decision, use Single Wall vs. Dual Wall Heat Shrink Tubing. A successful diameter check alone establishes neither an electrical rating nor a sealed connection.
To confirm a size, use the YOCL heat-shrink tubing catalogue and provide the series, exact size row, largest pass-over dimension, smallest covered dimension and required coverage length. Request the applicable dimensional limits and installation information for the intended material and duty.
References
- YOCL product information — HTS 2:1 Single-Wall Heat Shrink Tubing. Complete 39-row dimension table, nominal pair meaning and published ± fields; checked 6 October 2026.
- YOCL product information — HS3X 3:1 Dual-Wall Adhesive-Lined Heat Shrink Tubing. Complete 13-row dimension table and supplied/recovered limits; checked 6 October 2026.
- YOCL product information — HS4X 4:1 Dual-Wall Adhesive-Lined Heat Shrink Tubing. Complete nine-row dimension table and supplied/recovered limits; checked 6 October 2026.
- NASA Kennedy Space Center — KSC-E-165 Revision F, 20 December 2021, Electrical Ground Support Equipment Fabrication, Specification for. Section 3.8.1.1.1(a), printed page 59; dimensional principle within its ground-support-equipment scope.