OEM Sheet Metal Fabrication

What Information Should You Send for a Sheet Metal Fabrication Quote?

A common RFQ starts with a drawing and a quantity. Sometimes that is enough. Sometimes it is not.A simple laser-cut panel may be easy to understand from a PDF or DXF. A welded enclosure, CNC machined component or assembled cabinet usually needs more information before the manufacturer can quote it properly.The goal is not to prepare a perfect document package before contacting a supplier. It is to make sure the details that affect manufacturing are clear.At YT Manufacturing, we work with sheet metal parts, enclosures, cabinets, welded structures, CNC machined components and assembled products. Based on the projects we receive, the following information is the most useful when preparing a quotation. 1. Start with a Drawing — When the Part Needs OneFor simple products, a reference photo, sample or basic dimensions may be enough for an initial discussion.But once a part includes details that cannot be judged from appearance alone, an engineering drawing becomes necessary.Typical examples include:• Hole positions• Bend dimensions• Thread specifications• Mounting interfaces• Weld locations• Critical dimensions• Assembly clearancesA dimensioned 2D drawing is usually the clearest way to communicate these details.For enclosures, cabinets and fabricated assemblies, it also helps us understand how panels, doors, brackets and internal components should fit together.If your design has gone through several revisions, send the latest approved version and make the revision number clear. Quoting from an outdated drawing can create unnecessary work for both sides.   2. Add a STEP File for Complex Parts and Assemblies   For more complex projects, a 3D model is very useful.We normally recommend STEP/STP for 3D file exchange because it can be opened by different CAD systems and does not depend on both companies using the same native software version.STEP files are especially useful for:• Sheet metal enclosures• Electrical cabinets• Machine frames• Welded structures• CNC machined parts• Multi-part assembliesNative SolidWorks files such as SLDPRT and SLDASM can also be reviewed when available, but STEP is generally easier for supplier-to-customer file exchange.For 2D files, PDF, DWG and DXF are commonly used. IGES/IGS can also be reviewed for selected 3D geometry.For most custom metal projects, the most useful combination is:Dimensioned 2D drawing + STEP/STP model The drawing tells us what needs to be controlled. The 3D model helps us understand the overall structure.   3. Specify the Material as Clearly as You Can   “Steel” or “aluminum” is not always enough for production.Different grades can behave differently during forming, welding, machining and finishing.Common examples include:Carbon and Coated SteelSPCCDC01SGCCQ235Q355 Stainless Steel201304316 Aluminum50526061Project-specified gradesIf the material has already been approved by your engineering team, include the exact grade in the RFQ.If it has not been finalized, tell us how the product will be used. Indoor equipment, outdoor structures, visible consumer products and marine applications do not have the same material requirements.A material can then be reviewed together with the structure, manufacturing process and intended environment.   4. Confirm the Sheet or Plate ThicknessThickness affects more than material cost.It can also affect:RigidityBendabilityWeldingHardware installationProduct weightAssemblyIf a cabinet uses different thicknesses for the body, door, mounting plate and structural supports, show this clearly in the drawing or BOM.For machined plates or larger fabricated structures, plate thickness or starting stock size should also be included where available.One point worth mentioning: using thicker metal is not always the best way to improve strength.Bends, ribs, reinforcement, welded supports and load paths can have just as much influence on the final structure.   5. Define the Surface Finish   Surface finish can change both the manufacturing sequence and the quotation.Common finishes include:Powder coatingWet paintingBrushed stainless steelPolishingAnodizingHot-dip galvanizingNatural weathering finishProject-specified coatingsFor visible products, it is also useful to define:ColorGloss levelBrushing directionVisible surface requirementsAreas that should remain uncoatedThis matters for products such as self-service kiosks, electrical cabinets, electric fireplaces and outdoor furniture, where the exterior surface is part of the finished product.For example, “black powder coating” still leaves room for interpretation. If appearance matters, a RAL color, approved sample or other agreed reference is better.   6. Tell Us the Quantity You NeedQuantity affects production planning.It can influence:Material purchasingCutting and nestingSetup timeWelding fixturesSurface finishingAssembly planningPackagingA one-piece prototype and a repeat order of 200 sets may use the same drawing, but the production approach will not be exactly the same.If you are still in the development stage, it helps to provide both quantities.For example:Prototype: 1–3 setsExpected production: 100 sets per orderThis tells us whether the current quote is only for verification or may later move into repeat production.   7. Tell the Supplier What Needs to Be AssembledThis is one of the areas where RFQs are often too vague.There is a major difference between supplying an empty metal enclosure and supplying an enclosure with hardware, internal components and wiring already installed.Depending on the project, YT Manufacturing can support:PEM nuts and studsThreaded insertsHardware installationComponent mountingCable routingSelected internal wiringMechanical assemblyFor more complex assemblies, the following are useful:Assembly drawingBOMComponent listWiring diagramReference photosPhysical sampleFor example, on an electric fireplace project, the manufacturing scope may include not only the metal housing, but also control-board installation, LED component installation, internal wiring and final assembly.That needs to be clear before the price is calculated.   8. Explain How and Where the Product Will Be UsedA short description of the application can prevent the wrong material, finish or manufacturing approach from being quoted.Useful information includes:Indoor or outdoor useIndustrial environmentMarine environmentFrequent cleaningCustomer-facing visible surfacesElectrical equipment integrationOutdoor weather exposureStructural installationYou do not need to write a long technical report.A sentence such as:“This cabinet will be installed outdoors and will contain electrical control components.”is already much more useful than sending only a cabinet drawing with no application information.The same applies to solar mounting structures, outdoor furniture, medical equipment frames and self-service terminals. The application helps explain why certain materials, finishes and design details matter.   9. Mark the Dimensions That Really MatterNot every dimension on a sheet metal part needs the same level of control.If certain dimensions affect assembly or function, mark them clearly.Typical examples include:• Mounting-hole positions• Datum surfaces• Component interfaces• Door alignment• Machined surfaces• Hole patterns• Assembly clearancesThis is particularly relevant for automation equipment, machine frames and parts that must connect with components made by another supplier.If an inspection report is required for certain dimensions, mention that during the RFQ stage.It is much easier to plan the inspection method before production than after the parts have already been made.   10. Mention Special Packaging RequirementsOur normal quotation is based on the product plus regular protective packaging, unless otherwise stated.Freight is generally not included in the product price and is discussed separately according to destination, shipment volume and delivery terms.If your project requires special packaging, tell us during the quotation stage.Examples include:Custom retail cartonsSpecial foam protectionWooden casesHeavy-duty palletsIndividual protective packagingExtra protection for glassSurface protection for finished productsCustomer-specified packagingSpecial packaging may involve additional material, labor or packing volume, so it needs to be calculated separately.This is particularly relevant for finished products such as electric fireplaces and outdoor furniture, where packaging has to protect both the product structure and the visible surfaces.   What If the Design Is Not Finished Yet?Not every project starts with a complete drawing package.Some RFQs begin with:• A reference photo• A physical sample• A sketch• A preliminary drawing• A 3D model• A partial BOMThat is fine for an initial discussion.For simple products, a reference image and basic dimensions may already be enough to understand the general requirement.For parts where the structure is not obvious, or where hole positions, bends, threads, tolerances or assembly interfaces matter, engineering drawings will normally be required before an accurate quotation can be prepared.The useful approach is to tell us what has already been decided and what is still open.For example:Material: not finalizedFinish: black powder coating preferredQuantity: 50–100 setsApplication: indoor industrial equipmentDrawing: preliminary versionThat gives us something practical to work with.   Example 1: Electrical Cabinet RFQA useful cabinet inquiry might include:2D drawing: PDF3D model: STEPMaterial: SPCCThickness: 1.5 mm / 2.0 mmFinish: Powder coating, specified RAL colorQuantity: 50 setsAssembly: Internal mounting plate and hardware installationApplication: Indoor electrical equipmentIf cable-entry positions, ventilation openings or internal mounting requirements are important, they should also be shown.This allows the quotation to reflect the actual cabinet rather than a generic sheet metal box.   Example 2: CNC Machined Part RFQFor a CNC machined component, the RFQ may look like this:3D model: STEP2D drawing: PDFMaterial: 6061 aluminumQuantity: 20 / 100 / 500 pcsCritical tolerances: Marked on drawingFinish: AnodizingInspection: Critical dimensions to be recordedIn this case, the tolerance information may have a larger impact on machining and inspection than the overall size of the part.   Example 3: Finished OEM Product RFQFor a finished product such as an electric fireplace or an outdoor furniture program, the RFQ may include:• Product drawing or reference sample• Overall dimensions• Material and finish• Component list• Assembly requirements• Target quantity• Packaging requirements• Target market or applicationIf the product includes electrical or decorative components, the internal mounting and assembly requirements should also be provided.Standard protective packaging can be included in the product quotation. Special packaging and freight are normally reviewed separately.   A Simple RFQ ChecklistBefore sending your inquiry, check whether you can provide the following:• 2D drawing• 3D STEP/STP file• Material and grade• Sheet or plate thickness• Surface finish and color• Quantity• Assembly requirements• Application or operating environment• Critical tolerances• Inspection requirements• Special packaging requirements, if anyYou do not need to have every item finalized before contacting us.For simple products, a reference image, sample or basic dimensions may be enough to start the discussion. For parts with unclear geometry or critical assembly details, engineering drawings will normally be needed before the quotation can be finalized.   Need a Quote for a Custom Metal Project?Send us the information you already have — drawing, STEP file, material, quantity or reference sample — together with a short description of the project.YT Manufacturing supports sheet metal fabrication, CNC machining, welding, surface finishing, hardware and component installation, selected wiring and mechanical assembly according to the agreed manufacturing scope.    

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