UC Components provides Inch-measure vented, flat, and split lock washers to complement our vented and non-vented screws. Our vented flat washers promote faster, more complete pump-down of HV and UHV systems by providing a direct pathway for the evacuation of trapped volumes of air beneath fastener heads. All our washers are made 300 series stainless steel, and are available with the same vacuum-appropriate finishes as our RediVac fasteners. UC Components Inch vented and flat washers are manufactured to meet NAS 620 and AN960 standards. Lock washers are manufactured to MS-35338 standards.