Filiform needle

One of the nine needles of ancient China that has been developed into a variety of fine needles of varying length most commonly used in performing acupuncture today. The filiform needle is now generally made from a stainless steel wire that is sharpened at one end and has a thin wire of copper, stainless steel, or silver wrapped around its opposite end as a handle. Stainless steel is chosen for the body of the needle because of its flexibility, strength, and resistance to oxidation. Though silver and gold also resist oxidation, they are expensive and are relatively soft metals. Thus, they are used only in specific systems of practice when their pliability does not impede treatment. Filiform needles range in size from 15 mm to 150 mm in length and 0.22 mm to 0.30 mm (30 to 34 gauge) in diameter.