Everlasto 4mm Solid Braid Nylon Sash Cords. Solid braid nylon sash cords are made from strong solid braided nylon fibres and are our strongest sash cords. These 4mm cords are ideal for small sash windows with narrow pulley systems where a strong and wear resistant cord is required. As these cords are synthetic these nylon cords are waterproof and resist rot, mildew and mould. Also ideal for use with pulleys, as a synthetic clothesline or as a replacment starter cord for engines. Made in the UK by James Lever of Bolton.