Delrin balls also known as POM, acetal, polyacetal, polyformaldehyde, Polyoxymethylene and celcon, are used instead of stainless steel or steel balls in various industrial applications at lower cost than metal balls. the most common applications include medical products, micro pumps for spray, dispensers, precision instruments conditioning and automation equipment. Delrin / POM is characterized by its high strength, hardness and stiffness to -40 degrees. They also provide good mechanical characteristics, corrosion resistance, wear and abrasion resistance. POM is intrinsically opaque white, but it is available in all colors. They are even good electric insulators and auto lubricant materials. Hardness: 120 HRC Weight each: 0.213g Tensile strength: 11000 psi Bead finish: Polished Material resin: Delrin Max operating temp: Heat deflection 121 degrees, Melting point 178 degrees