Grainger Guitars was founded by brothers Darren and Gavin Grainger. Both had a background in precision engineering background, with skills including hydraulics, CNC machining,  3D CAD design and motor-sport fabrication. They make meticulously built, hand finished electric guitars their workshop in Oakham, UK. Grainger also make bridges and other guitar hardware.
Source: Grainger Guitars website (31 July 2022)