100,000+ part types machined. Every process under one roof. An engineer replies within 24 hours.
Since 1993, Zhongnan Machinery has machined the parts other shops turn down — deep holes to 12 metres, tolerances to 0.005 mm, finishes to Ra 0.4 μm, in alloys from 34CrNiMo6 to Inconel 718. Find your part family below, or send the drawing straight to our engineers.
Zhongnan is not a trading desk and not a single workshop. It is one group — ten specialized companies across six locations — built around a single discipline: parts that must not fail. Machining, deep-hole drilling, grinding, EDM, heat treatment, coating and plating, welding, metrology, and metal 3D printing — 40+ processes stay in-house. Your drawing never leaves our floor, and neither does your part. One quality system, one accountable team, one lead time.
Our machine-tool subsidiary designs and builds the CNC machines we run — gantry machining centers with travels to 12 metres (self-built FWG-M1260 series), a 7-axis CNC gun drill boring 6 metres deep, our own deep-hole drills and tooling. A factory that can build its machines can hold its tolerances.
Fuel injection and engine parts for low-speed two-stroke marine diesel engines, in batch production today:
| Part family | Proof point | Go to page |
|---|---|---|
| Common Rail Unit ★ | The full assembly — rail body, control blocks, valves, accumulator; first China-made unit, 2006; 7 classification societies | Send drawing → |
| Common Rail Pipe Family ★ | Fuel, servo, servo-oil & supply pipes; 12 m rails; 1,050 bar working / 1,450 bar tested; pressure-test record ships with the part | Send drawing → |
| Injector Nozzle Body | Precision ground to Ra 0.4 μm; small and micro-hole drilling | Send drawing → |
| Plunger & Barrel Pairs | Matched-pair fit clearance held in the 1.2–1.8 μm band; proven capability, made to print | Send drawing → |
| Pump Covers | Standard production part; fast quotation | Send drawing → |
| Pump Bodies | Plunger bores honed for micron fits; galleries gun-drilled & borescope-verified | Send drawing → |
| Injector Nozzles | Matched needle sets; seat cones ground to Ra 0.4 μm | Send drawing → |
| Safety & Relief Valves | Metal-to-metal seats Ra 0.4 μm; concentricity 0.002 mm | Send drawing → |
| Exhaust Valves | Heat-resistant alloys; hardfaced seats ground; stems chromed in-house | Exhaust Valves → |
Downhole-tool components proven at 180°C and 180 MPa:
| Part family | Proof point | Go to page |
|---|---|---|
| MWD / LWD Housings | Deep-hole + 5-axis in one group | Send drawing → |
| Drill Collars — Non-Magnetic & MWD | P550 non-magnetic stainless; full variant family | Send drawing → |
| Rotary-Steerable Components | Program-proven; systems we supply parts for have completed 3,700+ well operations | Send drawing → |
| Drive Shafts | Slender shafts to 4,500 mm, handled daily | Send drawing → |
| Valve Bodies | 17 key processes under one roof; bore groups in stable batch production | Send drawing → |
Commercial-program structural parts in nickel superalloys (IN718, GH4141, K4222):
| Part family | Proof point | Go to page |
|---|---|---|
| Aircraft Air Ducts | True simultaneous 5-axis machining | Send drawing → |
| Seal-Ring Shields | True 5-axis contours on Mazak VARIAXIS centers | Send drawing → |
| Valve Mounting Seats | Semi-finish and precision machining | Send drawing → |
Complete deep-sea manipulator arms in production:
| Part family | Proof point | Go to page |
|---|---|---|
| Deep-Sea Manipulator Components | Complete arms in production — everything except hydraulics and electronics machined in-house | Deep-Sea Components → |
One hundred thousand part types is not a marketing number. It is thirty-three years of drawings that mostly arrived with a problem attached: the material fought back, the hole was too deep, the tolerance was tighter than the shop’s machines, the previous supplier drifted out of spec. Most of those parts were non-standard custom work — one drawing, one engineered process, one documented delivery. Our senior technicians have twenty, some thirty years on the same processes. On our most demanding program, the core team’s shortest tenure is twelve years.
The families above are where our record runs deepest — not where it ends. The parts differ; the discipline does not: the same 5-axis machines, the same 12-metre-envelope deep-hole line, the same in-house surface treatment. If your part is precision-critical and its failure is not an option, this group is ready for it — whatever industry it comes from. And if it is not a fit, we will tell you honestly at the RFQ stage.
Upload your drawing — NDA first if you prefer. Within 24 hours an engineer responds with manufacturability feedback and risk flags. We then issue a calculated quotation; once confirmed, production runs with material certificates (heat-number traceability) and dimensional reports with every order. FAI packages and third-party inspection on request.
STEP, DWG, DXF, and PDF for quotation; native 2D/3D files are preferred for programming. Files are stored in an encrypted, access-controlled system — your drawing never leaves our facilities.
From 1 piece — no minimum order; one drawing is enough. Prototypes and the 10,000th piece share the same floor, machines, and process documentation, so there is no re-qualification wall when you scale.
It depends on material and process depth, but decades-long relationships with specialty-material suppliers mean faster material quotes and reliable lead times. Your quotation states a committed lead time — and because all 40+ processes are in-house, there are no subcontractor delays hidden inside it.
Upload your drawing (STEP / DWG / DXF / PDF) via the RFQ form. Within 24 hours an engineer replies with manufacturability feedback, process recommendations, and a calculated quotation — we do not provide instant quotes; each price is calculated from your drawing, material, and quantity, then confirmed with you step by step. NDA welcome, yours or ours; no drawing yet? A conversation works too.
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