07 / Assembly
Sheet Metal Enclosure Assembly Service
Doors, side panels, plinths, rails, shelves, locks, grounding conductors and buyer-supplied components are assembled from a controlled BOM and work sequence.
Scope
What Assembly Adds That Part Inspection Cannot Cover
Assembly turns individually acceptable parts into a functional product. Hole alignment, tolerance stack, door movement, gasket compression, hardware orientation and service access are therefore evaluated at the assembly level. The buyer and factory agree which components are supplied, installed and functionally checked.
Real production video
Cabinet Assembly on Our Shop Floor
These short clips show actual work at Fulei Metal. They support the process explanation; the controlled drawing and written quotation still define the final route.
Specifications
Assembly Specifications and Capabilities
| Scope | Sub-assembly through to complete enclosure assembly and functional fit check |
|---|---|
| Components | Fabricated parts, purchased hardware, gaskets, hinges, locks, fasteners, accessories |
| BOM control | Line-by-line BOM check against your drawing set before assembly starts |
| Torque control | Fasteners tightened to the torque value stated on your drawing |
| Fit checks | Door alignment, panel gaps, gasket compression, hardware operation |
| Finishing | Touch-up and surface protection before packing |
| Drawing formats | Assembly drawings with BOM, PDF, DWG, STEP, IGES or SolidWorks |
| Minimum order quantity | 10 pcs (large assemblies) / 50 pcs (medium assemblies) |
Final Checks
What Is Checked Before an Assembly Leaves
Assembly is where tolerance stack, coating build-up and hardware orientation become visible. These checks decide whether the enclosure still works after it is unpacked.
Individual parts can each pass inspection and still not fit together. Coating adds thickness to every mating face, a hinge needs clearance to swing, and a gasket only seals when it is compressed evenly. For that reason an assembly is checked as a unit, against the drawing and against the job the enclosure has to do — not part by part.
| Check | What is confirmed | Why it matters in service |
|---|---|---|
| Door and cover movement | Swing, gap, latch engagement, no rubbing | Binding after coating build-up is the most common complaint on a new enclosure |
| Mating hole patterns | Parts come together without force | Forced assembly hides a tolerance problem that returns in service |
| Installed hardware | Orientation, seating, thread condition | An insert that was not fully seated is found at final torque, not at goods-in |
| Gasket and sealing faces | Even compression, no twist or gap | The sealing performance of the finished enclosure rests on this |
| Earth and bonding points | Studs present, contact faces free of coating | Paint is an insulator; a bonding point has to be defined on the drawing |
| Internal layout | Panel, rail and cable routing clearances | Service access after delivery is decided here, not on site |
| Packing | Protection, labels, bagged hardware | Transit damage is the most expensive failure because it happens last |
The checks we can carry out are mechanical and dimensional: fit, movement, hardware torque, sealing face condition, and continuity where the drawing defines it. We can also add a leak or pressure test when it is agreed in advance, and record the result with the batch on the inspection record.
What we do not do is certify the finished equipment. We build to the gasket, gland and bonding specification you give us and record what we checked; type testing, ingress verification and electrical safety approval belong to the complete product and are carried out by you or by the certification body. Tell us which of these you need and we will prepare the assembly and the documentation to suit — the same way we handle drawing review questions before production starts.
Manufacturing route
How an Assembly Is Built and Released
- 01
Receive approved components against the BOM
- 02
Prepare subassemblies and verify mating features
- 03
Install hardware in a controlled sequence
- 04
Check movement, alignment and required functions
- 05
Record accessory count and release to packaging
Engineering checkpoints
BOM and Datum Decisions Before Assembly Starts
Each point below is settled before components are called in, because the expensive assembly problems are BOM and datum problems rather than workmanship problems.
BOM control
The assembly record must distinguish approved components from temporary or buyer-supplied items.
Tolerance stack
Rails, doors, panels and bases need common datums so acceptable parts form an acceptable assembly.
Torque and orientation
Project-critical fasteners and directional parts require an explicit work instruction.
Serviceability
Components should remain replaceable and accessible in the buyer's final equipment configuration.
Buyer input
What to Send With an Assembly Enquiry
These are the items that decide how the enclosure is built and checked. Without them the BOM has to be guessed, and a guessed BOM is reworked at the bench.
- Assembly drawing and controlled BOM
- Supplier responsibility for each component
- Torque, orientation and functional checks
- Labelling and accessory-pack requirements
- Photos or records needed before shipment
FAQ
Assembly Questions Buyers Ask Before Ordering
What do you need to quote an assembly?
The assembly drawing and the controlled BOM, with supplier responsibility stated for each component. Add the torque, orientation and functional check requirements, and any labelling or accessory-pack requirement for packing.
Can you build a pilot assembly before the batch?
Yes. A pilot build is where the BOM, the torque values, door movement and the bonding points are proven. Those are the items that are expensive to correct once fifty enclosures are packed.
What goes into the BOM you assemble from?
Fabricated sheet metal parts plus purchased hardware, gaskets, hinges, locks, fasteners and accessories. Buyer-supplied components are accepted when they arrive with the assembly drawing, and the assembly record distinguishes approved components from temporary or buyer-supplied items.
What is recorded before an assembly is packed?
Door and cover movement, mating hole patterns, hardware orientation and seating, gasket compression, earth and bonding points, and the accessory count are checked as a unit against the drawing. Mechanical and dimensional checks are carried out in-house; electrical safety and type-testing of the finished equipment remain with the equipment maker or a third party. See the inspection stages for what is recorded.
Can you assemble customer-supplied components?
Yes. We accept customer-supplied hardware, gaskets, hinges, locks and electrical accessories. Send them with the assembly drawing and BOM, and we will confirm quantities and any fit issues during the DFM review.
How is the assembled enclosure checked before packing?
Every assembled unit is checked for door and panel fit, hardware operation, gasket condition and accessory completeness against the BOM. Where a functional test is specified, we agree the test method and record the result before the unit is released to packing.
Send your drawings to our engineering team and we will return a DFM review together with the quotation. Request a quote, or see the full range on custom sheet metal fabrication.
Can you assemble with parts or hardware that we supply?
Yes. Send the BOM with the responsible supplier marked on each line, and we will receive, check and store the parts against it before the build starts. Shortages and transit damage are reported then, rather than at the end of the assembly.
Do you functionally test the assembled enclosure?
We check fit, movement, hardware torque, sealing faces and continuity where the drawing defines them, and we can add leak or pressure testing agreed in advance. Electrical safety, EMC and ingress type testing need certified equipment and are carried out on the finished product by you or by an approved laboratory.
Discuss a real project
Send the Assembly Drawing and the Controlled BOM
Send the assembly drawing and the controlled BOM. We will confirm component ownership, the fit checks and the functional checks, then quote from that.
Payment Terms
How a project is paid for is agreed before production starts, and the structure that applies to your order is stated on the quotation and on the order confirmation, so there is no ambiguity later.
- 30% advance payment with the order and the 70% balance before shipment — our standard structure.
- 70% advance payment with the order and the 30% balance before shipment — used for some projects.
- 100% payment in advance before production starts — used for some projects.
If your finance team works to a fixed structure, say so in the first enquiry and we will confirm what applies to your order before you commit. Request a quotation.
Questions buyers ask before sending drawings
The nine questions that come up most often before a project starts, answered the way we answer them by email.
What do you need from me to quote a part?
2D drawings as PDF, DWG or DXF, or 3D files as STEP, IGES or SolidWorks, together with material grade, sheet thickness, surface finish, quantity and destination country. If the drawing is not finished yet, send a photo, a sketch or the existing part instead — we review what can be measured from it and reply with the questions that still need answering.
How long does a quotation take?
Enquiries are answered within one business day. Quotation time depends on the part. Simple components we can price straight from the drawing — laser-cut and bent sheet metal, brackets, panels, covers, machine guards — are quoted within 24 hours. Complex work such as assembled kiosks, welded frames and multi-part structures is quoted after the drawing review and process confirmation, because the scope cannot be judged from the drawing alone; the date is confirmed in our reply.
Is there a minimum order quantity?
Prototypes are made from a single piece, and small batches of 10–50 pieces are routine. Prototype, first batch and repeat volume are quoted in one staged quotation so the numbers stay consistent as the project scales. See low MOQ sheet metal fabrication.
Can you work from a sample or a photo if I have no drawing?
Yes. Send the part itself, clear photographs with a rule or caliper in frame, or a dimensioned sketch. We measure what can be measured, list the features that are still undefined, and confirm them with you before production rather than assuming them.
Will you sign an NDA before I send drawings?
Yes. If your process requires one, say so in the first message and we will confirm what we can sign before any file is transmitted. Customer drawings are treated as confidential and used only for the project they were sent for. See our NDA page.
What payment and trade terms do you work with?
The standard structure is 30% advance payment with the order and the 70% balance before shipment. Some projects run on 70% advance payment with the 30% balance before shipment, and some on 100% payment in advance before production. Quotations are issued under EXW, FOB Ningbo, CIF or DDP, whichever your logistics team already works with.
What quality documents come with the parts?
Inspection documents are agreed with the order. Reports are provided on request, and material certificates and traceability can be supplied for the grades we purchase. Tell us in the enquiry which documents your own quality system requires, and we will confirm what we can provide before you order rather than after.
Who will handle my project?
One contact from drawing review through to shipment. Violet, our sales manager, coordinates drawings, DFM questions, quotation, samples, production updates and shipping documents, so you are not handed to a different person between quotation and delivery.
Can you scale from prototype to repeat production?
Yes. Prototype quantity and expected annual volume are quoted together, so tooling, nesting and packaging are planned once and the sample and production prices stay consistent. See prototype to production quotation and sheet metal DFM engineering review.
Trade Terms and Delivery
We quote under the standard Incoterms your logistics team already works with, and build the packing and documentation around the one you choose.
- EXW — you collect from our Ningbo facility and run export clearance through your own forwarder.
- FOB Ningbo — we deliver to the vessel at Ningbo port and handle export clearance.
- CIF — we cover carriage and insurance to your named destination port.
- DDP — we handle carriage, insurance, import clearance and duties through to your door.
Send your destination country, target delivery date and preferred trade term together with the drawing. Request a quotation.
Quotation Time
We quote from your drawings. How long that takes depends on what the part asks for:
- Simple parts — quoted within 24 hours. Laser-cut blanks and bent components, supplied with complete 2D or 3D drawings. Mon–Fri, GMT+8.
- Complex assemblies — quoted after the drawing review. Payment kiosks, multi-part welded frames, enclosures with purchased hardware, or anything needing a coating or assembly trial. We confirm a quotation date once the scope is clear.
Production lead time is quoted separately, after drawing review and process confirmation. Send your drawings.
Get a quote for this part
Send a drawing, or just the size and quantity. A sales engineer replies within 24 hours, Monday to Friday (China time).