1.Type:Ball Spring 2.Material: SS, carbon steel, 3.Size: M2-M30, #2-56-1/4-20 4,High quality,cheap price 1.Type: Ball spring2. Material: Stainless steel, ... carbon steel3. Thread Size: M2-M30, #2-56-1/4-204 ... and non-standard available Threaded delrin body Staniless steel press-in ball nose spring plunger