Archaeometallurgy: Spun vs Hammer-raised Toolmarks
冶金考古：旋制与捶揲痕迹的辨析
标签：冶金考古, 旋压溯源, 工艺痕迹, 显微观察
金属旋压在 19 世纪才随车床普及，古代铜器上出现"螺旋旋纹"即是断代疑点。辨析要点：①旋制件内壁有等距螺旋细纹（纹距等于进给量 0.3–1 mm），捶揲件为无序锤窝；②旋制壁厚沿母线平滑渐变，捶揲件呈 0.2–0.5 mm 波浪起伏；③旋制晶粒流线呈连续环向，捶揲件反复再结晶形成层状痕迹带。大英博物馆与中国国家博物馆对多件"疑似旋制"早期铜器的显微复检均确认为捶揲成形加车修口缘，此类痕迹学证据已成为文物定级与辨伪的重要依据。
Metal spinning spread only with 19th-century lathes, so spiral toolmarks on ancient copper are a dating red flag. Tell them apart: (1) spun interiors carry even helical lines spaced at the feed (0.3–1 mm); hammered work shows unordered dents. (2) Spun walls vary smoothly along the meridian; hammered walls wave by 0.2–0.5 mm. (3) Spun grain flows in continuous hoops; repeated recrystallisation leaves banded traces in raised work. Micro-inspections by the British Museum and National Museum of China both confirmed "suspect spun" early vessels as hammer-raised with lathe-trued rims — toolmark evidence now weighs in authentication.