Shipping CNC Parts from China: Packaging, Incoterms, Customs and Transit Times

The parts were perfect when they left Shenzhen. They arrived with two chipped anodized edges, a bent mounting ear on the third carton, and rust blooms on the 4140 shafts that spent three weeks in a humid container. Nothing about the machining was wrong. The packaging was.

Shipping machined parts is not the same problem as shipping general cargo. A 200 g aluminum bracket with a cosmetic anodized face is a delicate object that happens to be made of metal, and it survives a forklift, a container and a customs shed only if somebody planned for all three.

Packaging is part of the part

Machined parts fail in transit four ways: impact, abrasion, corrosion and deformation under load.

Three details are worth writing into the purchase order.

Corrosion protection for steel and cast iron. A 30-day sea voyage crosses multiple dew points, and condensation forms on cold metal inside a warm container. VCI film or paper plus 20 to 50 g of desiccant per cubic foot of sealed volume is standard for ferrous parts. Aluminum and stainless are less vulnerable but not immune, especially where machining has left embedded iron.

ISPM 15 for any solid wood. Crates and pallets of solid wood must be heat-treated or fumigated and stamped, or the shipment can be refused or re-exported at your cost. Plywood and engineered wood are exempt in most markets because they have been processed.

One more: air freight is charged on volumetric weight, so a crate 30% larger than necessary can cost 30% more to ship. Ask for packed dimensions and gross weight before the goods leave, and say in the RFQ if your parts are cosmetically critical, because a shop that knows the anodized face is visible will bag it separately.

Incoterms: who pays, who risks

Most shipping disputes are not about freight rates. They are about which costs and which risks belong to which party. Incoterms 2020 answers that in three letters, provided the named place is written down.

Two warnings. "FOB Shenzhen" and "FOB Yantian" differ in inland cost and terminal, so write the port. And DDP requires the seller to be the importer of record, which can mean a local entity and liability for compliance; a DDP rate that looks too low is often routed through a consolidator with unclear compliance, and the risk lands on your customs record.

CIF is chosen for convenience and chosen badly: the insurance it requires is minimum cover, which excludes handling damage and container condensation, two of the losses that actually happen to machined parts.

Customs documents

A clean entry needs six documents, and any inconsistency delays the shipment: a commercial invoice with description, quantity, unit price, value, Incoterm and origin; a packing list with carton count, dimensions and weights; a bill of lading or airway bill matching the consignee exactly; a certificate of origin if a trade agreement applies; an HS classification agreed with your broker; and any product-specific evidence such as material certificates.

The most common error is the description. "Metal parts" invites a query; "aluminum 6061-T6 machined mounting bracket, anodized, part number X" does not, and it helps your broker apply the right HS code. Values must be defensible too, because undervaluing an invoice is a customs offence and the penalty falls on the importer of record.

Transit times by mode

Add two to five days for customs clearance.

For production parts, the mode is a working-capital decision rather than a freight decision: air freight on 300 kg might cost $2,000 more and save three weeks of pipeline, and a stalled assembly line costs far more than that.

Protecting anodized and precision surfaces

Anodized surfaces are hard but brittle at edges, which is exactly where impact lands: protective film on cosmetic faces, no part-on-part contact anywhere in the carton, and corner protection on crates holding flat panels. Precision surfaces do not need to be hit to be damaged either, so bores rest on foam rather than on a hard pallet, heavy parts are blocked against movement, and critical threads get plastic caps.

Insure for at least 110% of invoice value plus freight, on Institute Cargo Clauses A rather than the minimum C. Photograph the pallet before sealing and the carton before opening, and keep the packaging until a claim settles. A claim with photographs, a packing list and a survey report is straightforward; one that says "some parts were bent" three weeks later is not.

At JSHS, export packing is quoted as a separate line so you can see what protection costs, and we pack to your carrier's requirements. Send your delivery address and volumes and the quote will show EXW and DAP side by side.

Frequently asked questions

Which Incoterm should a first-time buyer choose?

DAP is usually the least stressful for a first order, because the supplier handles transport and you keep control of import clearance and duty. EXW looks cheapest and is usually the most work, since you become responsible for export clearance in a country where you have no entity.

How much does sea freight save over air?

On a 200 kg shipment, sea LCL is typically 55% to 75% cheaper than air, but it takes four to five times as long. The trade-off depends on the value of the parts and the cost of the delay, not on the freight rate alone.

Do machined parts need a certificate of origin?

If your country has a trade agreement with China and you want the preferential duty rate, yes, and it must match the invoice. Otherwise a standard origin declaration on the invoice is usually enough.

What is the most common shipping mistake?

Packing for the warehouse rather than for the journey. Parts bagged for shelf storage, then loaded into a container without corrosion protection or internal blocking, account for most transit damage claims.