Multi-process metal part sourcing
Custom Metal Parts for OEM Builds, Prototypes, and Low-Volume Supply
Source housings, brackets, shafts, plates, fixtures, and mixed custom metal part packages through one engineering-led RFQ path. Great Material helps OEM buyers organize part families, process routes, material choices, finish requirements, and inspection-document scope before quote review starts.
Start here when a package spans multiple custom metal part types, then move into CNC machining services, CNC milling, CNC turning, surface finishing, and the final quote workflow.
RFQ planning card
- Accepted files: STEP, STP, IGES, X_T, SLDPRT, PDF, ZIP
- Part families: housings, brackets, shafts, plates, fixtures, heat sinks
- Common metals: aluminum, stainless steel, steel, brass, copper, titanium
- Documents: dimensional report, FAI, CoC, material certs
- Quote notes: finish, destination, packaging, NDA
| Best fit | OEM buyers sourcing several custom metal part types in one program |
| Primary CTA | Request a quote |
| Related pages | quality control, material certificates, RFQ drawing guide |
Use one review path for mixed custom metal part packages
Many RFQs include several part families at once. Buyers may still be grouping housings, brackets, shafts, plates, or fixtures while deciding whether each item is best produced through milling, turning, or supporting fabrication routes.
Great Material connects part type, process route, material choice, finish planning, and the final RFQ handoff so the project can move into pricing with clearer scope.
- Mixed part-number quote packages grouped by assembly or material
- Projects where CNC, sheet metal, finish, or secondary operations still need routing
- Programs where material, finish, and document scope must be defined before pricing
Part families
Housings, brackets, shafts, plates, fixtures, and heat sinks.
Core processes
CNC milling, CNC turning, sheet metal support, and secondary finishing.
Material planning
Aluminum, stainless steel, steel, brass, copper, and titanium.
Document scope
Finish notes, critical dimensions, FAI, and material certificates.
Quote-ready custom metal parts matrix
Use this matrix to map the part family to the likely manufacturing route before you prepare the final RFQ package.
| Part family | Best-fit process | Typical metals | Common finish or document notes |
|---|---|---|---|
| Housings and enclosures | CNC milling | 6061, 7075, 304, 316 | cosmetic faces, gasket grooves, tapped holes, finish class, report dimensions |
| Brackets and mounting parts | Milling or sheet metal fabrication | Steel, stainless steel, aluminum | thickness, bends, flatness, hole pattern, coating, visible faces |
| Shafts and round parts | CNC turning | 303, 304, 4140, brass, 6061 | OD and ID fits, threads, grooves, runout, concentricity |
| Fixtures and tooling plates | CNC milling | Aluminum, tool steel, 4140 | datum structure, locating features, repeatability, inspection points |
| Heat sinks and thermal plates | CNC milling | 6061, copper alloys | fin geometry, flatness, cosmetic treatment, contact surfaces |
| Mixed-process part packages | Split by process and grouped by part family | Project-dependent | group part numbers by material, finish, build stage, and document level |
Choose the manufacturing route before you send the full package
One of the most common delays in custom metal part quoting comes from sending a mixed project without separating which items should be milled, turned, or formed. A cleaner package reduces engineering clarification loops and makes pricing more comparable.
| Process | Best fit | RFQ note |
|---|---|---|
| CNC milling | housings, plates, fixtures, multi-face geometry | mark datum-sensitive features, cosmetic faces, and sealing surfaces |
| CNC turning | shafts, pins, bushings, fittings, cylindrical parts | define threads, runout, concentricity, and finish targets |
| Sheet metal support | covers, guards, bent brackets, lighter-gauge formed parts | call out thickness, bend logic, and coating direction |
| Secondary operations | tapping, inserts, grinding, finishing, light assembly | state which items need finish control or inspection records |
For packages focused entirely on machined parts, use CNC machining services. Use this page when the sourcing package spans several custom metal part families or when route choice is still under review.
Materials, finishes, and documents change the quote structure
The relationship between alloy, finish, and quality-document level needs to be defined early. Those choices change machining time, finish planning, handling, and final inspection logic.
| Category | Typical choices | Why it affects the quote |
|---|---|---|
| Materials | 6061, 7075, 304, 316, 17-4 PH, 1018, 4140, C360, C110, Ti-6Al-4V | material changes machining time, tool wear, finish compatibility, and cert needs |
| Finishes | anodizing, passivation, bead blasting, powder coating, black oxide | finish changes masking, cosmetic review, lead time, and packaging |
| Inspection documents | dimensional report, FAI, CoC, material certs | document level changes process planning and final acceptance steps |
Prototype, pilot, and repeat supply need different RFQ detail
A supplier can review the same geometry at different project stages, but the RFQ should not look the same each time. The more the program moves toward repeat supply, the more revision control and documentation matter.
| Build stage | What to include |
|---|---|
| Prototype | CAD, material intent, function-critical dimensions, finish expectations, and target quantity |
| Pilot run | final drawing revision, inspection requirements, cosmetic notes, and packaging direction |
| Repeat low-volume supply | approved documents, repeat quantity bands, revision control, and certificate expectations |
Where this page fits
- use this page first when the package still spans several part families
- move into process pages once route choice is settled
- move into quality pages when document scope becomes the main concern
- finish at the quote page with the final package
Multi-part RFQ readiness table
Top custom-parts pages often show process breadth or instant quoting. OEM buyers also need a practical way to package several part numbers so engineering review can separate geometry, material, finish, and inspection requirements without repeated clarification.
| RFQ grouping item | What to include | Why buyers include it | Review outcome |
|---|---|---|---|
| Part-number grouping | Assembly name, part number, revision, quantity, and related drawing | Keeps housings, brackets, shafts, and plates from being quoted as unrelated one-off parts | Cleaner quote structure and easier repeat-order review |
| Process route | Known preference or open review: milling, turning, sheet metal, secondary operations | Allows engineering review to choose the economical route without guessing intent | Better manufacturability feedback before final pricing |
| Critical features | Fits, datums, thread callouts, cosmetic zones, flatness or runout notes | Separates functional dimensions from ordinary geometry | More accurate inspection scope and fewer tolerance assumptions |
| Finish and handling | Anodizing, passivation, powder coating, bead blasting, masking, protected surfaces | Finish changes sequence, packaging, and cosmetic acceptance | Clearer surface-treatment planning across the whole package |
| Quality documents | Dimensional report, FAI, CoC, material certificate, revision record | Some part numbers need documentation while others only need standard inspection | Document cost and effort can be planned before machining starts |
RFQ checklist for custom metal parts
When a program spans several materials, finishes, or part families, RFQ completeness matters even more than on a single-process quote.
- CAD model and drawing set
- grouped part numbers and assembly relationships
- material by item
- finish by item
- critical dimensions and thread details
- inspection-document requests
- target lead time and destination country
- NDA requirement when needed
