copper flat washers designed for reliable sealing and long service life in automotive, plumbing, and industrial applications. Key benefits Durable, heatresistant material: Made from grade copper that resists and withstands temperatures up to 400°F, maintaining shape and sealing performance in heat environments. Consistent, leakresistant seal: Flat washer profile evenly distributes clamping pressure to prevent leaks and protect mating surfaces from deformation or damage. Broad compatibility: Covers full metric range M3 to M60 (includes common sizes M4, M6, M8, M10, M12, M14, M16), so one washer type fits a wide variety of bolts and fittings. performance: Multiple thickness options (1.0, 1.2, 1.5, 2.0, 3.0 mm) let you match sealing behavior to torque requirements and vibration levels for the assembly. Specifications Material: grade copper Temperature rating: Up to 400°F Bolt compatibility: M3 to M60 (including M4, M6, M8, M10, M12, M14, M16) Interior diameters (ID): 3 mm to 60 mm Exterior diameters (OD): 5 mm to 68 mm Thickness options: 1 mm, 1.2 mm, 1.5 mm, 2 mm, 3 mm Practical use guidance Select the washer ID that matches the bolt or stud shank for proper fit and even load transfer. Choose thicker washers (2–3 mm) where higher torque, heavy clamping, or vibration resistance is required; use thinner options (1–1.5 mm) for tight clearances or lower torque applications. The flat copper washer is used where a metaltometal seal and surface protection are needed, especially under repeated thermal cycling. Typical applications Hydraulic systems: Seals around fittings and banjo bolts to prevent fluid leaks in hydraulic lines and cylinders. Automotive and engine work: Use on oil, coolant, or brake line fittings and other engine connections that face heat and vibration. pressure plumbing and industrial fittings: Reliable sealing for pressurized plumbing joints and industrial assemblies where a durable metal washer is required. What this washer solves Stops common leak paths by creating an even, metaltometal sealing surface. Prevents surface damage from overtightening by spreading clamping force. Simplifies inventory and maintenance with one material and a wide range of metric sizes and thicknesses. tip Match washer ID to bolt size and choose thickness based on expected torque and vibration to ensure a reliable seal and long service life.