Compensating for irregularities of flat, curved, and uneven surfaces, spring-loaded engraving tools move within the toolholder of CNC milling machines. They provide constant pressure to the toolbit as it moves over part surfaces. The tools fit into standard 3 /4-in. collets or endmill toolholders. Tool kits include a solid-carbide toolbit, collet, and software that converts text into generic G code for engraving.