1.custom made 2.with screw thread 3.parts for pressure cooker 4. size: OEM, according to ... industry for more than 10 years. 1. Material Available: Copper, Brass, Aluminum, Stainless Steel, Steel alloy, etc.2. Specification: OEM, according ... , drilling etc.5. Equipment: CNC lathe, automatic lathe, hand lathe, thread rolling machine, tapping drilling machine etc.6. Surface Treatment: Plating ...