BS 419 – Specification for varnished fabrics and tapes for electrical purposes
Fabrics woven from cotton, silk, nylon, polyethylene terephthalate (PTP) and glass, coated with varnish, in full width of 36 in approx. or slit into tape. Yellow and black in nominal thicknesses 4 mil (0.10 mm) to 10 mil (0.25 mm). Thickness, width, length, joins, packaging, electric proof strength at 20°C and at 90°C, tensile strength, tearing strength, decrease in tearing strength with heat ageing in air, acidity, varnish stability, extensibility, confirmation of glass fabric base; test methods in appendices.
