How do I select 4 mm fiberglass insulating sleeving?

Measure the maximum finished outside diameter of the conductor, terminal or bundle. Choose an inner diameter that allows assembly clearance without excessive looseness, then confirm the fit with a representative sample.

Is 20 mm fiberglass sleeving available?

WCW fiberglass sleeving families cover approximately 0.5 mm to 35 mm depending on construction, so 20 mm is within the typical range. Confirm coating, wall build, tolerance and availability for the selected grade.

What is the difference between F-class and 200°C sleeving?

F-class commonly refers to a 155°C insulation-system direction. Silicone resin and silicone rubber fiberglass sleeving may support 200°C-class directions. Final selection must follow the end-product insulation system and validation standard.

SIZE & SPECIFICATION GUIDE

Fiberglass Insulating Sleeving Size Guide: 4 mm to 20 mm

Select a fiberglass insulating tube by finished conductor diameter, installation clearance, coating system, temperature class and validation requirement. WCW supplies acrylic, silicone resin and silicone rubber fiberglass sleeves in approximately 0.5-35 mm inner diameters depending on construction.

Request Size Samples Compare Common Sizes

0.5-35 mm range4 mm and 20 mm projects155°C / 200°C classesTypical 600V constructions

Silicone fiberglass insulating sleeving in multiple sizes — Confirm inner diameter, wall build and coating with production-representative samples

COMMON SEARCHED SIZES

Use nominal size only as the starting point

Nominal inner diameter	Typical evaluation	What to confirm
4 mm fiberglass insulating tube	Single leads, terminals and compact wire bundles near 4 mm finished OD	Maximum OD, insertion clearance, bend radius and wall build
10 mm fiberglass sleeve	Medium wire bundles, motor leads and transformer connections	Bundle shape, assembly method, abrasion and cut length
20 mm F-class fiberglass sleeve	Larger bundles or components requiring a 155°C-class material direction	Insulation-system class, coating, tolerance and dielectric test

Do not select a 4 mm sleeve for a measured 4 mm part without checking tolerances and installation method. A sample fit test is the most reliable approval step.

COATING OPTIONS

Match size with the correct insulation material

Acrylic fiberglass sleeving

A 155°C-class direction commonly evaluated for F-class motor and transformer insulation. Typical sizes are approximately 0.5-25 mm depending on construction.

Silicone resin fiberglass sleeving

A 200°C-class direction for electrical leads that need heat resistance, dielectric protection and dimensional stability. Typical sizes extend to approximately 35 mm.

View silicone resin specifications