K40

K40 may refer to several topics, most commonly potassium-40 and the K40 laser cutter. Potassium-40 (40K) is a naturally occurring radioactive isotope of potassium. It accounts for about 0.012% of natural potassium and has a half-life of roughly 1.25 billion years. 40K decays predominantly by beta-minus decay to calcium-40 (about 89%), and by electron capture to argon-40 (about 11%). This decay scheme makes 40K a key isotope in potassium–argon dating, a method used to determine the ages of rocks and minerals. The radiogenic decay of 40K also contributes to Earth’s internal heat.

In hobbyist technology, K40 refers to a budget CO2 laser cutter commonly sold under that name. These devices typically feature a 40-watt CO2 laser tube and an open-frame chassis, offering a compact footprint suitable for engraving and light cutting. Typical activities include working with materials such as acrylic, wood, fabric, and leather, often in work areas measured in a few hundred millimeters across. Control systems may use Ruida or GRBL-based controllers, with software options like RDWorks or LaserGRBL. While affordable and popular among makers, K40 machines often require assembly and upgrades, including improved air assist, cooling, and safety enhancements, along with proper ventilation and eye protection. The variation in components and build quality means performance and reliability can differ significantly between units.