Button springs (also commonly known as “pot springs,” “metal domes,” or “snap domes”) are made from ultra-thin (0.05 mm–0.1 mm thick) or ultra-thick (typically with higher hardness) 301 or 304 stainless steel. Button springs are a critical component of switches.
They are primarily used in membrane switches, dome-contact switches, PCBs, FPCs, medical devices, and other products. How button springs work: The button spring on a membrane switch is positioned over the conductive area of the PCB (mostly above the gold fingers on the circuit board). When pressed, the center of the spring depresses and makes contact with the circuit on the PCB, thereby forming a circuit. Current flows, allowing the entire product to function normally.
Hongmao’s metal springs are categorized by shape into: circular metal springs, cross-shaped metal springs, triangular metal springs, and oval metal springs. Diameters range from 3 mm to 20 mm, and actuation forces range from 100 g to 600 gf. Based on surface plating treatments, they can also be classified as: gold-plated, nickel-plated, silver-plated, and mirror-finished. There are two types: single-sided plating and double-sided plating.
Customizable Parameters
Dimensions: Typically 3 mm to 25 mm
Actuation Force: Standard range 100 gf to 600 gf (light/standard/heavy), with some options as low as 60 gf or as high as 6,000 gf
Material: SUS301 (high-elasticity stainless steel, most commonly used), SUS304, phosphor bronze
Surface Treatment: Nickel plating (rust-proof), silver plating (excellent conductivity), gold plating (high corrosion resistance and stability)
Contact Types: Standard smooth surface, silver-plated, gold-plated contacts
Substrate and Structure: PET film (Mylar) substrate; single-layer, double-layer (with spacers), EMI printing (anti-static), with plungers, and other structures
Array and Mounting: Single loose components, or custom multi-component assemblies per drawings (including positioning holes and alignment marks)
