Long, thin linear guide rails and sealed linear bearings are vulnerable in transit — bending, corrosion, and seal damage. This guide explains how HGR, MGN, and LMUU series components are packed for export, which Incoterms apply, transit times by mode, and the points buyers should confirm with their supplier before shipment.
A 3000 mm HGR rail is a long, slender steel beam with a ground raceway on one face. A sealed LMUU bearing is a precision housing with a lip seal that keeps abrasive dust out of the rolling elements. Neither survives rough handling, and both can be damaged by moisture long before the crate is opened. This guide covers how Xiamen Dongfeng Bearing packs linear guide rails and linear bearings for export, which Incoterms are supported, transit times by mode, and the details worth confirming before dispatch.
Key takeaways
- Rails up to 2000 mm ship in export cartons with foam protection; 3000–4000 mm rails require custom wooden crates with steel-reinforced supports to resist bending in transit.
- Individual parts are anti-corrosion oiled and vacuum-sealed in plastic bags; bulk export uses a wooden crate with a moisture barrier.
- Packaging quantity is per-carton defined: 20 sets per carton for MGN9–12, 10 for MGN15; 50 pieces per carton for LMUU6–20, 25 for LMUU25–40, 10 for LMUU50–60.
- Incoterms supported: EXW, FOB, DAP, DDP. FOB Xiamen is the standard loading port.
Why Long Rails and Sealed Bearings Are Fragile in Transit
The failure modes for linear motion components are mechanical and chemical, and they happen at different points in the journey.
Bending. A rail has high stiffness along its axis but limited resistance to point loads across its length. If a 4000 mm rail is supported only at its ends inside a container, its own weight plus vibration and stacking pressure can produce permanent deflection. A bent rail will not sit flat on a machined mounting surface, and the carriage will not run smoothly along the full stroke. Once a rail takes a set, it cannot be straightened back to tolerance.
Corrosion. Bearing steel and the ground raceway surfaces are unprotected against humidity. A sea container crossing the equator cycles through large temperature swings, and condensation forms on cold metal. Without an oil film and a sealed barrier, surface rust appears on the raceway within weeks. Light surface rust is enough to change running torque and accelerate wear on the rolling elements.
Seal and raceway damage. The lip seal on a sealed linear bearing is a thin elastomer edge. If parts shift inside a carton and rub against each other, or if a bearing is dropped onto a hard surface, the seal can be nicked or pushed out of position. The raceway inside the housing can also take brinelling marks from impact. Both problems are invisible from outside the carton and typically only show up at assembly.
Packaging Stages: From Anti-Corrosion Oil to Wooden Crates
Export packaging for linear motion components is a sequence, and each stage addresses one of the failure modes above. The table below summarizes the stages and what each is intended to prevent.
| Stage | What is done | What it prevents |
|---|---|---|
| Anti-corrosion oil | Individual parts are coated with anti-corrosion oil | Surface rust on raceways and bearing steel during sea transit |
| Vacuum sealing | Oiled parts are vacuum-sealed in plastic bags | Humidity contact; oil loss during handling |
| Carton packing | Foam-lined partitioned cartons, quantity per carton by model | Part-to-part rubbing, seal nicks, raceway impact |
| Rail cartons | Rails up to 2000 mm in export cartons with foam protection | Handling damage on short and mid-length rails |
| Wooden crates | 3000–4000 mm rails in custom wooden crates with steel-reinforced supports | Bending and sagging across the rail length |
| Moisture barrier | Wooden crate with moisture barrier for bulk export | Condensation inside the crate during temperature swings |
Step 1 — Anti-Corrosion Oil and Vacuum Sealing
Every individual part is oiled and then vacuum-sealed in a plastic bag. The oil film protects the ground surfaces; the vacuum bag keeps that film in place and blocks humid air from reaching the metal. This step matters most for sealed bearings and for the raceway face of rails, because those are the surfaces that determine running accuracy.
Step 2 — Foam-Lined Partitioned Cartons
Sealed parts are packed into foam-lined cartons with partitions, so components do not touch each other in transit. Carton quantities are fixed by model, which makes order planning and container loading predictable:
- MGN9–12: 20 sets per carton
- MGN15: 10 sets per carton
- LMUU6–20: 50 pieces per carton
- LMUU25–40: 25 pieces per carton
- LMUU50–60: 10 pieces per carton
If your application uses sealed extended-length bearings, the packing configuration for those models is worth confirming on the quotation. The LMUU series sealed extended-length linear bearing and the MGN series stainless steel miniature linear guide both fall under the partitioned-carton rules above.
Step 3 — Rail Cartons for Lengths Up to 2000 mm
Rails up to 2000 mm ship in export cartons with foam protection. At this length, the rail is stiff enough that a properly fitted carton with foam end-blocks keeps it supported and separated from other items. The carton itself is a handling unit — it protects the rail from impact and from contact with adjacent cargo, and it should not be opened and repacked in transit.
Step 4 — Custom Wooden Crates for 3000–4000 mm Rails
Beyond 2000 mm, a carton alone is not enough. Rails of 3000–4000 mm are packed in custom wooden crates with steel-reinforced supports positioned along the length so the rail cannot sag or take a permanent bend. The supports carry the rail at intervals; the crate walls protect the raceway from impact. For bulk export, the wooden crate also includes a moisture barrier to limit condensation inside the crate as the container moves through different climate zones.
At 4000 mm, the shipment may fall under an oversized cargo surcharge depending on the carrier and route. This is a freight cost item, not a product cost item, and it is worth asking about at quotation stage rather than after booking.
Long Rails and Precision: What Packaging Cannot Do
Packaging manages transport risk. It does not guarantee the condition of the goods on arrival, and it does not replace inspection. Buyers importing long rails should treat the crate as a controlled handling unit and inspect on receipt before assembly — that is the point at which any transit issue becomes visible and can be raised while evidence is fresh.
Incoterms and Who Arranges Shipping
Xiamen Dongfeng Bearing supports four Incoterms for linear guide rail shipments: EXW, FOB, DAP, and DDP. The choice determines who books freight, who carries risk at which point, and how much of the logistics work falls on your side.
| Incoterm | Who arranges main freight | Typical use for linear rail orders |
|---|---|---|
| EXW | Buyer | Buyers with their own freight forwarder in China who want full control of consolidation |
| FOB Xiamen | Buyer, from the port of loading | Standard export arrangement; supplier delivers to Xiamen and loads |
| DAP | Supplier | Buyers who want delivery to their site and will handle import clearance themselves |
| DDP | Supplier | Buyers who want a single delivered arrangement including import clearance |
FOB Xiamen is the standard loading port. Sea freight transit is typically 25–35 days to Europe and 18–25 days to the USA, depending on port pair and routing. For samples, express service runs 5–7 days. Express is a reasonable option for a sample set of sealed bearings or a short rail section, but not for full-length 3000–4000 mm rails, which exceed express size limits.
What to Confirm With Your Supplier Before Shipment
Most transit disputes trace back to unconfirmed details at order stage. These are the points worth settling in writing before dispatch.
- Rail length and packing type. Confirm which models fall into carton packing and which require a wooden crate. A 2000 mm rail and a 3000 mm rail ship differently, and the change affects both crate cost and freight surcharges.
- Quantity per carton. Match your order quantity against the per-carton figures above so you know how many cartons and how many handling units to expect.
- Incoterm and named place. Confirm the exact term and the named place, not just the three-letter code.
- Oversized cargo. If any rail is 4000 mm, ask whether the route and carrier apply an oversized cargo surcharge before the booking is made.
- Stock status and lead time. In-stock HGR20/25/30 ship in 7–10 business days; LMUU6–30 in-stock items also ship in 7–10 business days, while LMUU40–60 run 15–20 business days. Confirm against your target delivery date.
- Documentation. Confirm the packing list reflects carton counts and crate dimensions, so receiving and inspection are straightforward.
FAQ
How are linear rails shipped?
Rails up to 2000 mm are packed in export cartons with foam protection. Rails of 3000–4000 mm are packed in custom wooden crates with steel-reinforced supports to prevent bending in transit. Individual parts are anti-corrosion oiled and vacuum-sealed in plastic bags before packing, and bulk export shipments use a wooden crate with a moisture barrier.
Why do linear rails rust during shipping?
Sea transit exposes rails to repeated temperature swings, and condensation forms on cold metal inside a container. If the raceway surfaces are not oiled and sealed against humidity, surface rust appears on the ground faces. The anti-corrosion oil film plus the vacuum-sealed bag is the barrier that limits this; for bulk export, the wooden crate also carries a moisture barrier.
What Incoterms do you support for linear guide rail orders?
EXW, FOB Xiamen, DAP, and DDP. FOB Xiamen is the standard loading port. Sea freight is typically 25–35 days to Europe and 18–25 days to the USA; samples by express arrive in 5–7 days.
Can long rails be shipped by express?
Express works for samples of sealed bearings or short rail sections, with 5–7 day transit. Full-length 3000–4000 mm rails exceed express size limits and are shipped by sea in crated packing.
Ordering and Dispatch
Xiamen Dongfeng Bearing operates a 5000 sqm factory and exports to more than 50 countries. If you are planning an order that includes long rails and sealed bearings, the packing type, per-carton quantity, Incoterm, and lead time are the four items to settle before booking. Send your rail lengths, model list, target quantity, and destination port, and we can confirm packing configuration and dispatch schedule.