Bus handrail brackets are traditionally made of aluminum alloy die-casting. However, since aluminum alloy is not as strong as steel or stainless steel, for the sake of safety, many handrail brackets are now made of steel or stainless steel, which can increase the strength. Ensure life safety. The most suitable process for producing this kind of steel or stainless steel bracket is investment casting. Carbon steel casting parts or stainless steel casting parts have very superior advantages in terms of strength and cost. Therefore, many industrial structural parts now use the investment casting process to produce spare parts to meet the requirements of precision and strength of the parts.