Carbide Chisel for stone with knurled handle. Set of Chisels 4mm+8mm-3pcs+3pcs | eBay
Carbide Chisel Guillet Universe European Width 4 to 20 mm (Width 15 mm) : Amazon.co.uk: DIY & Tools
Stone Masonry Tungsten Carbide Granite Lettering Chisels Hammer Head Green | Al-Orr, Tungsten for Granite Masoning, Tungsten Tools for Granite Lettering