A Study on the Evolution of Metal Materials Used in Filiform Needles for Acupuncture

Abstract: By sorting out the evolution of the metallic materials of filiform needles for acupuncture (毫针) in combination with the history of ancient metal smelting, this paper argues that the invention of filiform needles was only feasible when metal smelting technology had advanced to a certain stage. During the Bronze Age, medical needles were likely made of both bronze and Bian Shi (砭石 stone needle). However, bronze was not suitable for manufacturing filiform needles; it was iron, rather than bronze, that completely replaced Bian Shi as the primary material for medical needles. Filiform needles first emerged in the Han dynasty, with wrought iron as the dominant material. With the innovation and advancement of metal smelting techniques, the craftsmanship of iron filiform needles underwent substantial refinement. The needle bodies became increasingly slender, and the needle handles were crafted into a circular shape. This technological progress laid the foundation for the emergence of acupuncture manipulation techniques in the Song and Yuan dynasties and their further development during the Ming and Qing dynasties. Throughout ancient Chinese history, filiform needles were predominantly made of wrought iron until the advent of steel filiform needles in modern times. The development of modern stainless-steel filiform needles in China originated from the advocacy of Cheng Dan’an (承淡安). This paper clarifies the application of different materials for filiform needles across various historical periods and confirms the fact that China is the birthplace of stainless steel filiform needles. It is found that the transformation of filiform needle materials has enhanced the safety and reliability of acupuncture, alleviated the pain associated with needling, reduced acupuncture-related complications and adverse effects, enriched the content of clinical acupuncture to varying degrees, and promoted the development of clinical acupuncture practice. In conclusion, the authors hold that in the new historical era, sorting out the historical evolution of filiform needle materials provides important reference and enlightenment for the innovation and improvement of acupuncture instruments.