... , Design Service Offered Crystal Resonator Shell1.matrial:copper,iron,aluminium,Kover2.specification: 55*22 36*22 36* ... treatment:weld,sintering ,polishing,sand blast4.bottom case:silver-alloy brazing,tin soldering5.other sizes and types are workable7 ... Material:Brass,CRS,Stainless steel,Kovar,Copper-Nickel-Zinc Alloy,Iron nickel alloyProduction process:Stamping,Forming,Cutting,Punching,Positioning, ...