喇叭口撞釘|Trumpet-mouth carving tool

Overview Trumpet-mouth carving tool China 20th century On view at The Met Fifth Avenue in Gallery 222 These steel drills with blunt points (zhuangding or dingzi 
in Chinese), flat heads (tuozi), or curving heads (wazi) are used for high relief carving, undercutting, and fine shaping of small jade works. The craftsman holds the jade in one hand against the drill, which is mounted on a spinning shaft. He or she rotates the shaft using foot treadles, while continuously applying abrasives, usually sand mixed with water, to the tip of the drill, which cuts the jade.