I'm Ling Jin — a mechanical engineer who runs your sourcing in China. Machined, die-cast and extruded parts, technically vetted and landed at your dock: tolerances checked, tariffs planned, paperwork handled.
I'm Ling Jin — a nationally certified senior mechanical engineer with 13 years inside China's metal manufacturing: aluminum building systems, CNC contract machining, die casting and IR optics. Small companies use me as the China engineering team they don't have in-house; growing ones, as their QC department — from sourcing to shipping.
I read your drawings myself — tolerance, draft, material — before a factory quotes.
Years inside these shops as customer and auditor. Machine lists and scrap rates, not certificates.
Loading plans, packaging, documentation — parts arrive usable, not just finished.
These factories ensure reliable production capacity. Detailed factory information is available upon request. As I am not a middleman, all costs are completely transparent.
We talk on the shop floor — one engineer accountable from quote to container.
3/4-axis milling and turning across vetted CNC shops — fixtures, tolerances and first articles checked before anything ships.
Fiber laser cutting, CNC bending and welding — from flat pattern to finished enclosure, one-off to volume.
Aluminum die casting with mold, machining and finishing planned together — porosity managed, not discovered.
Custom dies and profile extrusion, then precision machining of the extruded part — one chain from billet to component.
Deburring, grinding, anodizing and powder coating — the finish is specified on the drawing and inspected, not left to chance.
FEA and DFM review before metal is cut — stress, material and tolerance checked against how the part is actually made.
Representative Projects — Cost Reduction, Process Improvement, New Design from Scratch, Assembly Optimization, Factory Selection, etc.
The part was CNC-turned from bar stock — material waste and machine time were eating the margin at volume. Redesigned for aluminum die casting, machining only the critical faces.
The customer had a load requirement but no design. I engineered the structure, ran the FEA, and filed the patent in their name.
Before any metal was cut, the design went through FEA — stress hotspots reinforced, excess material removed. Production ran on a verified drawing, not a guess.
Sheet-metal enclosure + machined brackets + extruded rails, sourced across three specialist shops, kitted and QC'd as a single deliverable.
One closed loop — your idea to serial delivery, with one engineer accountable at every step.