Sheet Metal Fabrication From China: Quotes and Specs

Start with the finished part and its intended use

Whether you need a replacement bracket, a small run of enclosures or repeat production, describe what the part must do. Include mating components, loads, operating environment, visible surfaces and destination market. Ask the supplier to identify manufacturing concerns before quoting.

Separate prototype, initial production and repeat-order quantities. Ask which operations the quoting supplier performs and which it subcontracts, particularly welding and finishing. Make proposed material substitutions or design changes subject to written approval.

Which fabrication processes does your order need?

Ask suppliers to quote the same completed part. Compare a flat-blank quote with a formed, welded and finished-part quote only after reconciling the included operations and inspection.

Specify the material and thickness without relying on shorthand

Choose the material for the application. Specify the required material standard and grade rather than relying on descriptions such as mild steel, stainless steel, aluminium or coated steel. State the supply condition where relevant, nominal sheet thickness and acceptable thickness variation. Require approval before using a proposed equivalent.

Ask the fabricator to review material, thickness, bend geometry, hole locations and stiffness requirements together. Request confirmation that its proposed process and tooling can produce your particular design.

For stainless steel, specify the required surface appearance and direction of any brushed grain. For coated sheet, agree how cut edges, bends and weld areas will be treated. Request material evidence linked to the supplied batch rather than accepting appearance as proof of material identity.

What to send for a useful quote: DXF, STEP and PDF

Send a controlled drawing package in formats the supplier accepts. Consider DXF for flat cutting geometry, STEP for the formed part or assembly, and a dimensioned PDF for material, tolerances, finishes and inspection notes.

Put the same part number and revision on every file, state the units, and identify which document controls if files disagree. Label a flat pattern as buyer-controlled or reference-only. Ask who is responsible for the developed blank and bend allowances.

Add quantities by part, expected repeat demand, mating-part information, required delivery destination and packaging needs. If you only have a sketch or physical sample, request drawing preparation and approval before authorising production.

Use the drawings and tolerances checklist for document control and dimensioning details. If dedicated punching tooling is involved, use the sheet metal punching tools guide for that narrower purchase.

Agree tolerances for the finished part

Do not use cutting accuracy alone to set acceptance requirements for a bent and welded assembly. Specify the features that control fit: hole positions, mating faces, flange dimensions, bend angles, flatness and overall assembly dimensions.

Ask the supplier to propose achievable tolerances for your geometry and explain how it will measure them. Agree requirements for the actual material, processes, geometry and inspection method rather than adopting a universal numerical tolerance.

ISO 9013:2017 covers geometrical specifications and quality tolerances for thermal cuts, including laser cuts within its stated scope. If referencing it, agree the applicable requirements and amendments. Specify acceptance criteria for bending, welding and the completed assembly separately.

State whether each critical dimension is checked before or after finishing, and whether the part is measured free-standing or in an agreed fixture. Approve a representative finished sample and its measurement report before batch production.

Specify finishes and read the quote line by line

Define the finish system, colour, texture, visible surfaces and any masking of threads, contact areas or mating faces. Agree an appearance reference and how parts will be protected during packing. Use the anodising, plating and powder-coating guide for finish selection and detailed specifications.

Ask each supplier to identify material, fabrication, tooling, finishing, inspection and packing within its scope. Confirm currency, quotation validity, payment stages, sample approval, production lead-time trigger and delivery responsibilities with a named location.

Ask suppliers to explain the cost implications of material utilisation, cutting complexity, bend setups, welding and dressing, dedicated tooling, finishing, inspection and packaging. Request a revised quote before accepting a proposed design change.

Check quality before the order leaves China

Agree an inspection plan before production. Identify critical characteristics, the parts to be inspected, measurement methods, acceptance criteria and the action required for failures. Make shipment of parts that depart from the specification subject to written approval.

Include checks of material records and thickness, finished dimensions, burrs and sharp edges, bend direction, distortion, weld condition, installed hardware and finish appearance. Test assembly with a mating part or agreed fixture where fit matters.

Agree suitable tests for required material, weld or coating properties rather than relying solely on visual checks. Request an inspection report that identifies the order, drawing revision, checked parts, results and supporting photographs.

Specify packaging to protect against rubbing, bent flanges and moisture during the planned journey. Require part identification and batch traceability through packing, and agree the procedure for reporting and resolving defects.

If you sell in the US or EU

US customs — checked 18 October 2026: CBP states that the importer of record remains responsible for correct entry documentation and applicable duties, taxes and fees even when using a broker. Prepare an accurate description of the part, material and intended use. USTR's Section 301 search provides coverage and additional-duty information by tariff subheading. Check the actual classification and all applicable import measures before shipping; do not treat a Section 301 result as the total duty payable.

US food-contact applications — checked 18 October 2026: FDA explains that the regulatory status of a food-contact material depends on its constituent substances and that applicable authorisation specifications and limitations must be met. If the part or its coating will contact food, request compliance evidence covering its composition and intended conditions of use.

EU — checked 18 October 2026: European Commission guidance says CE marking is required only for products covered by legislation providing for it and must not be affixed to other products. Establish the product's intended use and applicable rules before specifying CE marking.

UK example: customs value and import VAT

For an illustrative order delivered to Cambridge, build a landed-cost estimate by checking which packing, transport, insurance, clearance and applicable import charges are already included in the accepted fabrication quote and which must be added.

HMRC guidance checked 18 October 2026: under transaction-value valuation, transport, insurance, loading and handling costs connected with delivery to the UK border must be included unless already counted. For import VAT, start with customs value and add applicable import duties and other import charges, excluding VAT itself, plus relevant incidental expenses to the first UK destination. Include relevant expenses for a further UK destination if that destination is known at importation. Avoid counting the same cost twice.

Use the classification and valuation rules for your actual goods and route. This example does not prescribe a commodity code, duty rate or VAT rate for every sheet metal order.

Get help preparing and comparing your fabrication enquiry

For help defining the order and comparing supplier responses, see Cambridge China Bridge's sheet metal fabrication sourcing service. Bring the drawings, intended use, quantities, destination and existing quotes so the required work can be scoped.

Ask for written confirmation of whether factory checks and goods inspections are included, what they cover, and whether third-party work attracts additional charges. Agree the scope and fees before commissioning the work.

Sources

Official regulatory and standards sources were checked on 18 October 2026. Manufacturer guidance supports the process, drawing and finishing discussion; it does not establish another supplier's capabilities. The checklists are purchasing recommendations, not universal production tolerances, prices or contractual terms.