The LD-396 assortment combines brass flat washers with rubber O-ring sealing rings to provide a versatile sealing and load-distribution solution for plumbing, electrical, hydraulic, and general mechanical applications. Brass H62/H65 flat washers offer excellent corrosion resistance, electrical conductivity, and a decorative gold finish that resists tarnishing in damp environments. The brass material provides good malleability, allowing the washer to conform slightly to uneven surfaces for improved load distribution and reduced surface damage when the fastener is torqued. Brass washers are particularly valued in plumbing and electrical applications where corrosion resistance and conductivity are essential, as they will not rust or degrade when exposed to water, moisture, or mild chemicals over extended periods.

The rubber O-rings included in this assortment serve as precision sealing elements that create leak-proof barriers between mating surfaces under compression. When installed in a groove and compressed between two components, the elastomeric O-ring deforms to fill clearances and surface irregularities, blocking the passage of liquids and gases. NBR (nitrile butadiene rubber) O-rings are the general-purpose choice, offering excellent resistance to petroleum-based oils, fuels, and hydraulic fluids, while silicone O-rings provide superior temperature resistance for high-heat and food-grade applications. The assortment covers inner diameters from 3mm to 50mm with cross-sections from 1mm to 5mm, matching the sealing requirements of most metric fittings, valves, and housings encountered in maintenance and assembly work.

Material selection is critical for achieving reliable long-term sealing performance, and the LD-396 assortment provides options to suit diverse operating conditions. Brass washers are specified where corrosion resistance, electrical conductivity, or aesthetic appeal is required, while optional copper, aluminum, and PTFE washers extend the range to high-temperature, non-conductive, or chemical-resistant applications. For O-rings, the 60-80 Shore A hardness range allows users to select softer compounds for improved sealing on rough surfaces or harder compounds for higher-pressure resistance and reduced extrusion. FPM (Viton) green O-rings are available for aggressive chemical and high-temperature environments, while red silicone O-rings serve food-grade and extreme-temperature applications, giving technicians the flexibility to match each seal to its specific service condition.

In plumbing systems, the brass washers distribute clamping loads across soft fixture materials and provide a seal-friendly bearing surface, while the rubber O-rings seal threaded connections, valve stems, and faucet cartridges to prevent leaks. In electrical applications, brass washers serve as conductive bonding and grounding components under terminal lugs and bus bar connections, and O-rings seal enclosure gaskets to maintain IP-rated protection against moisture and dust ingress. The assortment is equally valuable in hydraulic and pneumatic systems, automotive fuel and oil line service, appliance assembly, and industrial machinery maintenance, making it an essential inventory item for repair shops, maintenance departments, and OEM production lines that require reliable sealing and load-distribution components in a comprehensive range of metric sizes.