Category: Clay Sand Casting
Zhaoyuqi Machinery custom-manufactures cast iron parts — mechanical components and structural pieces made to buyer drawings. For more than 20 years we have sand-cast grey and ductile iron parts for machinery, equipment, construction and general industry, delivering finished, inspected components rather than raw castings.
We cast the iron components that go into machines and structures: brackets and supports, housings and gear cases, machine bases and frames, counterweights, linkages, pulley and wheel parts, and custom structural castings. That list is descriptive rather than limiting, because every piece is produced to a drawing rather than picked from a range.
What we actually ship most often is worth naming. Machine tool bases and slides, where mass and damping decide the finish the tool can hold. Gearbox housings, where bore alignment matters more than wall thickness. Flywheels and pulleys, where balance is the specification nobody writes down. Pump bodies and valve blocks that have to hold pressure at a machined face. Frame brackets, counterweights, rail and construction hardware, and load-bearing plates for steel structures. Each is poured in ductile or grey iron according to duty, with machining and coating added to suit your assembly line rather than our convenience.
Choose ductile iron for loaded parts such as gears, brackets and bodies under fatigue, because its nodular structure delivers strength with enough toughness to warn you before it breaks. Grey iron suits machine bases, heavy housings and vibration-sensitive frames, where damping and wear resistance matter more than elongation. When a drawing says only "cast iron", share the load case and we will propose a grade, state the cost impact, and certify nodularity above 90% on ductile pieces. Getting this wrong is expensive in one direction only: an under-graded part fails in service, an over-graded one merely costs more.
The line itself sets the outer frame. Automatic clay sand moulding covers 0.5 to 50 kg, which is where most brackets, housings and gear cases sit. Larger mechanical bodies, heavy bases and structural plates up to 200 kg go to lost foam casting, which avoids hard tooling and keeps medium and small batches viable. As-cast tolerance is CT10 to CT13; anything tighter is brought in by machining afterwards, and at quotation we say which faces are worth machining and which are not.
Send the 2D or 3D drawing together with the load data and required iron grade. Our engineers review risering, shrinkage risk and machining allowance before quoting, because those three decide whether the first sample is right or merely close. The sample is poured and measured before you approve it, bulk repeats the locked pattern and recipe, and finished castings are inspected 100% and crated for export.
Three things make an inquiry easier to price. Mark the critical dimension and tolerance on the drawing, so we know which faces carry the fit. State the annual quantity early, because tooling cost spreads over volume and a small first order can look expensive for no reason beyond that. Tell us the final assembly environment, whether humid, outdoors or corrosive, so the coating is chosen once instead of being redone after the parts arrive. For anything urgent, the quote form reaches the same engineering desk that prices the job.
"Machined" means different things on different quotes, which is why two castings with identical drawings can price 40% apart. We split machining into three tiers so you can buy exactly the accuracy the part needs:
As-cast, shot blasted: casting tolerances only, roughly ISO 8062 CT10–CT12 on our automatic green sand line. Right for brackets, weights and covers where bolt slots have clearance.
Drilled and tapped: mounting holes and threads produced after casting on drill lines. This tier covers most hardware — casting surfaces stay as-cast, only the holes are precise.
Fully machined: datumed CNC work on bores, faces and fits to your tolerances. Housings, bearing seats and anything mating with another part live here.
The tier decision should come from how the part works, not from habit. A mounting face sitting against a rubber pad does not need machining; a bearing bore does. Mark the functional surfaces on the drawing and the quote will price only those.
When we review drawings, the question that surprises buyers most is "what does this part sit on while we machine it?" Every casting needs a clamping and locating scheme, and the datum surfaces you choose decide how many setups the part needs. One setup on a CNC center is the cheapest machining you can buy; three setups triple the handling, the fixturing and the tolerance stack. If you mark the sealing face and two datum holes, we can usually hold the part in one or two setups — and the price shows it.
A common misunderstanding in sourcing cast-and-machined parts is expecting the casting to be accurate everywhere. It will not be, and it does not need to be. The casting contributes a rough envelope; machining creates the precision. Where this becomes a real problem is when a drawing dimensions a machined feature from an as-cast surface with a tight tolerance — the machinist must first establish where that as-cast surface actually is, which means indicating the part in, which means time.
The fix is a datum scheme agreed before quotation: pick two or three surfaces that will be machined first, and dimension everything else from them. Parts designed this way machine faster, scrap less, and hold tolerance across batches. On high-volume parts, it also lets us build a fixture once and reuse it, which is where the cost difference between a well-dimensioned part and a badly dimensioned one becomes permanent rather than one-off.
Machine parts usually need more than a shot blast. Options we run include priming and finish painting for equipment exposed to coolant or weather, powder coating for parts handled in assembly, and oil or VCI protection for machined faces that will sit in storage before assembly. Zinc-rich primer is the sensible default for parts that see occasional moisture but not immersion.
One specification habit worth adopting: state the surface preparation before the coating. A paint system applied over a poorly blasted surface fails at the interface long before the paint itself breaks down. We blast to a defined profile before coating, and if your paint supplier specifies a profile or a primer system, pass it along — it is cheaper to match it at our end than to rework parts at yours.
Yes, but the first cut must clean up whatever the casting tolerance left, so we ask for the machining allowance rather than assuming it. Tight tolerance to an unmachined cast face usually costs more than datum-ing off a machined spot first.
Sometimes. Send the casting and the drawing; we evaluate the allowance and distortion first, because machining someone else's casting without their process data is how scrap gets blamed on the wrong party.
Shot blasting to a uniform matte profile is standard before painting or powder coating. If your paint supplier specified a profile depth, pass it on and we blast to it.
Machined faces get rust-preventive oil and VCI paper, then wooden crates. Castings routinely arrive in Europe and North America without surface claims.
Yes, and it is often the best value: holes are what usually need precision, while the rest of the casting can stay as-cast. This tier prices well on hardware-class parts.
STEP for the model plus a PDF drawing with tolerances, datums and the critical characteristics marked. Native CAD is welcome but not required.
Each cast iron part we ship is 100% inspected before packing — dimensions, surface and ductile iron material quality verified to your drawing standard. We run drawing-based OEM production from sample approval through bulk sand casting, with a 10,000 t/y capacity and a regular 30-day lead time. Send the part drawing with your enquiry and we will prepare a quotation the same day.
Send your drawing and target quantity; we check moldability first, then come back with price and sample schedule.
Reference price range: US$0.10 to 100.00 per piece, FOB Qingdao. Minimum order quantity: 500 pieces per item. The final unit price is quoted against your drawing and depends on part weight, material grade, moulding process, machining allowance and tooling amortisation. Reference prices are valid until 31 December 2027.
Professional technical research and development team to provide customers with the best solution.
Jimo District, Qingdao City, Shandong Province, China
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