Heat Shrink Boot Size and Material Reference Guide
Heat Shrink Boot Size and Material Reference Guide
Selecting a heat shrink boot requires matching two sets of parameters: dimensional sizing (entry and exit diameters, leg lengths, and shrink ratios) and material specification (temperature rating, chemical resistance, and compliance standards).
This reference guide provides dimensional data tables, material comparison charts, and specification cross-references for the main heat shrink transition boot series — covering straight, angled, Y-shape, T-shape, and 1-to-3 configurations in polyolefin, PVDF, and elastomer materials.
How to Read Heat Shrink Boot Dimensions
Every heat shrink boot size is defined by the following key dimensions:
| Dimension | Description |
|---|---|
| D1 (Entry ID) | Inner diameter of the large opening — fits over connector backshell or cable trunk |
| D2 (Exit ID) | Inner diameter of the cable exit leg(s) — must clear the cable bundle OD |
| L1 (Body Length) | Length of the boot body from entry to the start of the exit leg |
| L2 (Leg Length) | Length of the exit leg(s) |
| Shrink Ratio | 2:1 (most common) or 3:1 for dual-wall versions |
| Recovered D1 | D1 after full shrinkage (= D1 supplied ÷ shrink ratio) |
| Recovered D2 | D2 after full shrinkage (= D2 supplied ÷ shrink ratio) |
Important: All dimensions listed in size tables are before shrinking (as-supplied state). Always verify that the recovered dimensions will grip your cable or backshell OD.
Sizing Rule of Thumb
For a reliable grip and seal after shrinking:
- As-supplied D1 should be ≥ 1.15× the connector backshell or trunk OD
- Recovered D1 should be ≤ 0.95× the connector backshell or trunk OD
- As-supplied D2 should be ≥ 1.1× the cable bundle OD
- Recovered D2 should be ≤ 0.9× the cable bundle OD
If the cable OD is at the edge of the recovery range, size up to the next boot and use additional sleeving on the cable to fill the gap, or select a 3:1 shrink ratio dual-wall boot.
Straight Boot Size Reference (202A / 202K Series)
Standard straight transition boots — 2:1 shrink ratio
| Size | D1 As-Supplied (mm) | D1 Recovered (mm) | D2 As-Supplied (mm) | D2 Recovered (mm) | Body Length (mm) | 202A-0 | 12.7 | 6.4 | 6.4 | 3.2 | 38 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 202A-1 | 19.1 | 9.5 | 9.5 | 4.8 | 51 | 202A-2 | 25.4 | 12.7 | 12.7 | 6.4 | 64 |
| 202A-3 | 31.8 | 15.9 | 15.9 | 7.9 | 76 | 202A-4 | 38.1 | 19.1 | 19.1 | 9.5 | 89 |
| 202A-5 | 50.8 | 25.4 | 25.4 | 12.7 | 102 | 202A-6 | 63.5 | 31.8 | 31.8 | 15.9 | 114 |
202K series = same dimensions in PVDF (Kynar) material
90° Angle Boot Size Reference (222D / 222K Series)
Right-angle transition boots — 2:1 shrink ratio
| Size | D1 As-Supplied (mm) | D1 Recovered (mm) | D2 As-Supplied (mm) | D2 Recovered (mm) | Body Length (mm) |
|---|---|---|---|---|---|
| 222D-1 | 19.1 | 9.5 | 9.5 | 4.8 | 51 |
| 222D-3 | 31.8 | 15.9 | 15.9 | 7.9 | 76 |
| 222D-5 | 50.8 | 25.4 | 25.4 | 12.7 | 102 |
222K series = same dimensions in PVDF (Kynar) material
Y-Shape Boot Size Reference (382A Series)
Two-leg branch boots — 2:1 shrink ratio
| Size | D1 Trunk (mm) | D1 Recovered (mm) | D2 Leg As-Supplied (mm) | D2 Leg Recovered (mm) | Trunk Length (mm) | Leg Length (mm) | 382A-1 | 19.1 | 9.5 | 9.5 | 4.8 | 38 | 51 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 382A-2 | 25.4 | 12.7 | 12.7 | 6.4 | 51 | 64 | 382A-3 | 31.8 | 15.9 | 15.9 | 7.9 | 64 | 76 |
| 382A-4 | 38.1 | 19.1 | 19.1 | 9.5 | 76 | 89 | 382A-5 | 50.8 | 25.4 | 25.4 | 12.7 | 89 | 102 |
1-to-3 Boot Size Reference (462A Series)
Three-leg fan-out boots — 2:1 shrink ratio
| Size | D1 Trunk (mm) | D1 Recovered (mm) | D2 Leg As-Supplied (mm) | D2 Leg Recovered (mm) | Trunk Length (mm) |
|---|---|---|---|---|---|
| 462A-3 | 31.8 | 15.9 | 12.7 | 6.4 | 64 |
| 462A-5 | 50.8 | 25.4 | 19.1 | 9.5 | 89 |
Note: All dimensional data above is representative reference data for standard series. Exact dimensions may vary by manufacturer. Request our full dimensional datasheet for precise specifications.
Material Reference Chart
| Material | Operating Temp | Shrink Temp | Shrink Ratio | Chemical Resistance | Flexibility After Shrink | Flame Rating | Spec Compliance | Polyolefin (std) | -55°C to +135°C | ≥120°C | 2:1 | Moderate | Moderate | UL 94 V-2 | UL 224 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Polyolefin (dual-wall) | -55°C to +110°C | ≥120°C | 3:1 | Moderate | Moderate | UL 94 V-2 | UL 224 | PVDF (Kynar) | -55°C to +175°C | ≥150°C | 2:1 | Excellent (fuels, oils, solvents) | Semi-rigid | UL 94 V-0 | MIL-DTL-23053/16 |
| PVDF dual-wall | -55°C to +175°C | ≥150°C | 3:1 | Excellent | Semi-rigid | UL 94 V-0 | MIL-DTL-23053/16 | Elastomer | -75°C to +150°C | ≥120°C | 2:1 | Good (oils, water) | Highly flexible | Self-extinguishing | — |
Connector Backshell OD to Boot Entry Size — Quick Match Table
Use this table to quickly identify the boot entry size for common connector families:
| Connector Family | Shell Size | Backshell OD (approx. mm) | Recommended Boot Entry Size | MIL-DTL-38999 | Size 9 | 14–16 | 202A-1 / 222D-1 |
|---|---|---|---|---|---|---|---|
| MIL-DTL-38999 | Size 11 | 18–20 | 202A-1 / 222D-1 | MIL-DTL-38999 | Size 13 | 22–25 | 202A-2 / 222D-2 |
| MIL-DTL-38999 | Size 15 | 26–30 | 202A-2 / 222D-2 | MIL-DTL-38999 | Size 17 | 31–35 | 202A-3 / 222D-3 |
| MIL-DTL-38999 | Size 19 | 36–40 | 202A-4 / 222D-4 | MIL-DTL-38999 | Size 21 | 41–46 | 202A-4 / 222D-4 |
| MIL-DTL-38999 | Size 23 | 47–52 | 202A-5 / 222D-5 | Deutsch DT | 2-pin | 18–20 | 202A-1 |
| Deutsch DT | 4-pin | 22–25 | 202A-2 | Deutsch DT | 6-pin | 26–30 | 202A-2 |
| Deutsch HD | 06 | 30–34 | 202A-3 | Deutsch HD | 10 | 38–42 | 202A-4 |
These are approximate references. Always measure the actual backshell OD before final boot selection.
Raychem Series Cross-Reference
| Raychem Part Series | Boot Type | Material | Equivalent Series |
|---|---|---|---|
| 202K | Straight | PVDF (Kynar) | 202K (PVDF equivalent) |
| 222K | 90° Angle | PVDF (Kynar) | 222K (PVDF equivalent) |
| 382A | Y-Shape | Polyolefin | 382A equivalent |
| 462A | 1-to-3 | Polyolefin | 462A equivalent |
Specification Standards Reference
| Standard | Scope | Material | Applies To |
|---|---|---|---|
| MIL-DTL-23053/16 | Military heat shrink tubing and boots | PVDF | Defense, aerospace, government procurement |
| AMS-DTL-23053 | Aerospace heat shrink products | Various | Commercial aerospace, OEM |
| UL 224 | Commercial heat shrink tubing | Polyolefin | Industrial, commercial |
| IEC 60684 | International shrinkable sleeving | Various | Global export / CE-marked products |
| SAE AS23053 | Aerospace shrink tubing | Various | SAE aerospace specifications |
How to Order: Information Required
When requesting a quote or placing an order for heat shrink boots, provide the following:
- Boot type — Straight / 90° / 45° / Y / T / 1-to-3
- Size number — e.g., 202A-2, 222D-3
- Material — Polyolefin / PVDF / Elastomer / Dual-wall
- Quantity — Units per order
- Connector reference (optional) — Backshell part number for sizing verification
- Specification (if applicable) — MIL-DTL-23053/16, AMS, UL, etc.
Frequently Asked Questions
How do I find the right size heat shrink boot?
Measure the outer diameter of your connector backshell (for the entry) and the outer diameter of your cable bundle (for the exit leg). Select a boot where the as-supplied entry ID is at least 1.15× the backshell OD, and the recovered ID is no more than 0.95× the backshell OD.
What is the difference between 202A and 202K boots?
202A boots are made from polyolefin for general-purpose applications. 202K boots are the PVDF (Kynar) version, offering higher temperature resistance (up to 175°C) and compliance with MIL-DTL-23053/16 for aerospace and military use.
What shrink temperature do I need for PVDF heat shrink boots?
PVDF (Kynar) boots require a minimum shrink temperature of approximately 150°C. Use an industrial heat gun with a temperature setting above 150°C, or a dedicated reflective nozzle for even heat distribution.
Can I use a standard heat gun for heat shrink boots?
Yes. A standard industrial heat gun at the appropriate temperature setting is suitable. For large boots or PVDF material, a reflective nozzle attachment or bench heat tunnel ensures uniform shrinkage.
What is a 3:1 shrink ratio boot?
A 3:1 shrink ratio boot shrinks to one-third of its as-supplied diameter. These are typically dual-wall adhesive-lined boots, allowing them to fit a wider range of cable diameters and provide a more positive seal than 2:1 ratio boots.
Are your boots compliant with MIL-DTL-23053/16?
Our PVDF (202K / 222K series) boots are manufactured to meet the functional requirements of MIL-DTL-23053/16. Full test reports and material certifications are available on request.
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