Fiber Academy · Lesson 11
Cable openers: opening loose-tube cables safely
A cable opener scores the outer jacket without touching the loose tube underneath. Ten seconds of tool discipline saves meters of wasted cable.
Lesson 11 ≈ 8 min lesson · Illustrated step-by-step guide
- 1
Set the depth by cable diameter
The blade should score roughly one third of the jacket thickness. Too deep cuts the tube; too shallow slides off.
- 2
Score around the jacket, then flex
Rotate the opener around the cable several turns, then flex the cable — the jacket snaps cleanly at the score line.
- 3
Ring-cut the far end and slit lengthwise
For longer openings use the longitudinal slitting blade, supporting the cable so the blade does not dive toward the tube.
- 4
Extract tubes and strength member
Cut the aramid/steel strength member with side cutters at the jacket edge — never pull it out through the opening.
- 5
Clean the gel before any fiber work
Gel on the tube means gel on your gloves, tools and finally on the fiber. Clean first, work second.
Field tips from TEKCN engineers
- Dedicate one opener per cable size on big jobs; adjusting depth repeatedly is where mistakes happen.
- If you feel the blade touch the loose tube, stop — inspect before continuing, or cut back and start again.