⭐️Compression Die Spring 2 Pieces⭐️ Hole Diameter (Outer Diameter): 20 mm Inner Diameter (Tolerance +0.5 mm): 11 mm Free Length: 25 mm (+/- 2 mm) Maximum Compression Rate: 32% Color: Red Load Type: Medium Load Material: 65Mn Rectangular section, closed end design. Die springs are mainly used in mold machinery, plastic injection, and 3D printer electrical components. Made of 65Mn material, the surface is painted red, making it rust-resistant and durable. 9-29 3D Printer Die Spring TM 20 mm Outer Diameter 25 mm Length Spiral Stamping Medium Load Compression Mold Die Spring Electrical Components for 3D Printer Red 2 Pieces $321