10/20/2026
How many wires fit in one tube?
Wrong question, and it's why bundles end up in sleeves that won't slide on or won't grip.
A bundle isn't sized by its gauge. It's sized by its widest diameter.
The tube has to do two things:
→ slide over the bundle, so the supplied size sits comfortably above it
→ grip it, so the recovered size sits below it
1/2" 2:1 tubing is 12.7mm supplied and recovers to about 6.4mm, so it grips a bundle 7–11mm across. The full chart, 1/4" to 2", is on slide 3.
One catch: 2:1 single wall grips, but its ends aren't sealed. Anything wet (weather, washdown, engine bay, bilge, salt air) needs 3:1 dual wall, adhesive-lined.
Save this for the next harness. Full guide: https://www.helixalindustrial.com/blog/2-1-heat-shrink-tubing-uses
What's the biggest bundle you've ever sleeved in one go?
