When an overseas HVAC or refrigeration buyer sends a drawing with a short RFQ, the real question behind it is usually simple: will these parts match our assembly every time, on time, with documentation we can rely on? At Yijin, a drawing-specific order is built around that question — starting from the submitted component revision, through material confirmation, forming, inspection, traceability and export packaging. The story below walks through how a copper and aluminum fitting order actually moves through our Xinxiang workshop.
Drawing review before production
At the inquiry stage, our engineering team compares the submitted drawing revision against the available copper and aluminum fitting ranges. The review covers run and branch diameters, branch angle, center height, end configuration, alloy and temper, and the stated tolerances. Where a dimension is ambiguous, the next step is a written question to the buyer. Confirming these details early helps prevent a component from reaching assembly with the wrong port position or geometry.

Material and process confirmation
For copper branch fittings, material requirements are reviewed against the customer-specified grade, including TP2 / C12200-class requirements where applicable. Aluminum components are specified by alloy and temper before forming. Production parameters and any required approval for a process change form part of the manufacturing review for the component.
Forming, inspection and cleanliness control
Depending on the approved design, an order may include copper tee and branch fittings, aluminum tees, return bends or formed tube assemblies. After forming, dimensional checks are matched to the drawing and the agreed acceptance scope. Inspection and laboratory testing are defined for the relevant component. Internal cleanliness and protective packaging are also reviewed because chips, swarf or loose debris can affect a refrigeration circuit.
Documentation and sample-first approach
Feasibility, tooling needs, minimum order quantity, cost and timing are confirmed after technical review. A sample-first approach allows the buyer and manufacturer to agree on geometry and acceptance requirements before volume production. Inspection records, test reports and any requested RoHS or REACH documentation should be confirmed for the applicable product range, scope and date before ordering.
Overseas buyers often send a drawing with a short RFQ and a target delivery date. Our recommendation: include the material grade, outside diameter, wall thickness, port sizes, tolerances, quantity, inspection standard and application in the first message. That lets our team quote on the real geometry instead of a generic catalog price.
About Yijin — Xinxiang Yijin Metal Products Co., Ltd., founded in 2014 and based in Xinxiang, Henan, manufactures copper and aluminum refrigeration fittings: copper tees, aluminum tees, return bends and formed tube assemblies for HVAC, refrigeration equipment, condensers and evaporators. Share your drawing for a technical review and quotation.



