Cable ties look like a simple product, but a wrongly chosen size or material is the most common reason a tie snaps, slips or crumbles outdoors after the first winter. This guide explains simply how to choose cable ties by three criteria: size, tensile strength and material.
1. Size: length depends on bundle diameter
Rule of thumb — the tie should be about 3–4 times longer than the bundle diameter, leaving enough to wrap around and lock securely. The Kraften range includes 8 sizes:
| Size (length × width) | Max bundle Ø | Holds | Typical use |
|---|---|---|---|
| 100×2.5 mm | Ø 3–20.5 mm | up to 8 kg | Thin wires, home electronics |
| 150×3.6 mm | Ø 2–36 mm | up to 18 kg | Electrical installation, switchboards |
| 200×2.5 mm | Ø 3–50.5 mm | up to 8 kg | Longer but light bundles |
| 200×3.6 mm | Ø 3–52.5 mm | up to 18 kg | Universal choice |
| 250×4.5 mm | Ø 3–65 mm | up to 22 kg | Construction, cable runs |
| 300×4.8 mm | Ø 4–80 mm | up to 22 kg | Pipes, conduit |
| 370×4.8 mm | Ø 4–102 mm | up to 22 kg | Large bundles, fences |
| 370×7.6 mm | Ø 6–102 mm | up to 45 kg | Heavy loads, machinery |
If in doubt between two lengths — pick the longer one. Excess can always be trimmed; a too-short tie cannot be extended.
2. Tensile strength: width matters more than length
A tie’s holding power is determined by its width. A narrow 2.5 mm tie holds up to 8 kg — enough for household wiring. For electrical installation and construction choose at least 3.6 mm (up to 18 kg), and for machinery, cable trunks or heavy loads — 7.6 mm wide ties holding up to 45 kg.
Important: the stated strength is static tensile load. If the fastening is exposed to vibration (e.g. in a vehicle or on machinery), choose one size stronger than the calculated load.
3. Material: why PA66 and not cheap recycled plastic
Quality cable ties are made of virgin polyamide PA66. Cheap ties made of recycled plastic are brittle: they snap when tightened and crumble outdoors within months. Kraften Premium ties are made only of virgin PA66 with UV stabilisers, which means they:
- hold the declared tensile strength (8–45 kg depending on size);
- withstand temperatures from −40 °C to +85 °C;
- carry UL94V-2 flammability class — self-extinguishing, suitable for switchboards;
- comply with RoHS and REACH.
Common mistakes when choosing
A too-narrow tie for a heavy load. A 2.5 mm tie is not meant to hold a cable trunk — use 4.8 or 7.6 mm.
A white tie outdoors. White (natural PA66) ties without UV stabilisers degrade outside. For outdoor use choose black UV-resistant ties.
Tightening “all the way”. An over-tightened tie cuts into cable insulation. Tighten just enough that the bundle doesn’t move.
The short answer
For household jobs, 100–200 mm long and 2.5–3.6 mm wide ties are enough. For professional electrical installation choose 3.6–4.8 mm width, and for heavy loads and outdoor use — black 370×7.6 mm ties made of PA66 with UV stabilisers. Find all 8 sizes on the Kraften Premium cable ties page — delivery within 1–2 business days across Lithuania.
