S-90718A140 4.3 mm ID x 9 mm OD UL 94 HB Plastic Washers

Key Features & Benefits at a Glance

• Superior durability with glass-filled nylon construction that resists wear, deformation, and impact in demanding environments.
• Excellent electrical insulation properties for safe use in electrical assemblies, preventing short circuits and enhancing equipment reliability.
• High-temperature resistance up to 220°F ensures stable performance in applications exposed to heat without losing structural integrity.
• Corrosion and chemical resistance thanks to the inert nature of nylon plastic, ideal for humid or corrosive industrial settings.
• Precision metric sizing (4.3mm ID, 9mm OD for M4 screws) guarantees easy installation and secure fit, reducing assembly time and errors.
• UL 94 HB flammability certification provides added safety by meeting recognized standards for slow-burning materials.
• Compliance with RoHS 3 and REACH regulations ensures environmental safety and broad acceptability in global markets.

Professional Applications & Engineering Value

This M4 metric flat washer made from glass-filled nylon plastic addresses common industrial challenges such as galvanic corrosion, electrical conductivity, and component degradation. Its black color and robust Rockwell M111 hardness make it suitable for automotive, electronics, and machinery applications where reliable insulation and corrosion resistance are critical. By eliminating metal-to-metal contact, it prevents seizing and reduces maintenance needs, while the high-temperature capability ensures longevity in environments with thermal cycling. Engineers value its lightweight yet strong profile for optimizing assembly efficiency and meeting stringent UL 94 HB safety standards.

Specification Summary & Compliance

This washer features precise dimensions with an inner diameter of 4.3mm and outer diameter of 9mm, designed for M4 screw sizes in metric systems. It conforms to UL 94 HB specifications for flammability and is manufactured to ensure consistent performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, affirming its adherence to environmental and health safety standards without hazardous substances.