Material selection
Materials for Custom Metal Parts
Select practical materials for CNC machining, metal 3D printing, finishing, and global delivery. Final availability and substitutions are confirmed during engineering review.
Common Materials
Aluminum
Lightweight CNC prototypes and production parts, commonly 6061 and 7075.
Stainless Steel
Corrosion-resistant machined and printed parts for functional applications.
Titanium
High strength-to-weight ratio parts for demanding prototypes and non-regulated use cases.
Inconel
High-temperature nickel alloy parts, often best evaluated for metal additive manufacturing.
Tool Steel
Wear-resistant machined components, jigs, and production tooling parts.
Not Sure
Submit the use case and constraints so engineering can recommend a material path.
Material matrix
Material and Process Fit
Use this table as RFQ guidance. Final availability, substitutions, heat treatment, and finish compatibility are confirmed during engineering review.
| Material family | Typical use | CNC fit | Metal AM fit | Finish notes |
|---|---|---|---|---|
| Aluminum 6061 / 7075 | General prototypes, brackets, housings, fixtures | Excellent | Use AlSi10Mg for additive alternatives | Anodizing, bead blast, chem film, as-machined |
| Stainless 303 / 304 / 316 / 17-4 PH | Corrosion-resistant shafts, plates, fittings, functional parts | Excellent | 316L and 17-4 PH are common AM options | Passivation, polishing, bead blast |
| Carbon and alloy steel | Wear parts, fixtures, shafts, structural prototypes | Good | Usually CNC unless geometry requires AM | Black oxide, plating, heat treatment when specified |
| Tool and mold steels | Jigs, tooling, wear surfaces, mold components | Good with drawing review | Special review required | Heat treatment and hardness targets must be specified |
| Titanium / Inconel | Lightweight or high-temperature demanding prototypes | Manual review required | Strong fit for selected geometries | Inspection, support removal, and post-machining assumptions matter |
| Copper / brass / bronze | Electrical, thermal, bearing, decorative, and fluid components | Good by alloy | Copper alloys require capability review | Polishing, passivation-like cleaning, or coating by application |
For regulated aerospace, medical, or defense use, certification and compliance review must be completed before quoting.
Tolerance guidance
Tolerance Inputs That Speed Up Quoting
Tolerances drive cost, supplier selection, inspection effort, and lead time. Upload drawings when dimensions are critical.
| Tolerance class | When to use | Required input | Quoting impact |
|---|---|---|---|
| Standard commercial | General prototypes and non-critical fit surfaces | STEP/STP model plus material and finish | Fastest engineering triage |
| Tight CNC tolerance | Bearing fits, dowel holes, sealing faces, precision assemblies | 2D drawing with datums, critical dimensions, and inspection notes | Requires supplier confirmation and may increase cost |
| Post-machined AM features | Printed parts with critical holes, planes, threads, or mating faces | CAD, drawing, and clearly marked machined features | Quoted as additive plus CNC finishing |
| Cosmetic surfaces | Visible housings, panels, consumer-facing parts | Marked cosmetic faces, finish target, color/texture references | May add masking, finish samples, or extra inspection |
If no drawing is provided, the quote will use standard assumptions and may list exclusions for unmarked critical dimensions.
Documentation
Material Documentation to Request
Documentation should be named in the RFQ when it affects purchasing approval, incoming inspection, or regulated-use review.
| Document | When it matters | RFQ input | Quote effect |
|---|---|---|---|
| Material certificate | Traceability, incoming inspection, procurement records | Material grade and certificate requirement | May constrain suppliers and add lead time |
| Heat treatment record | Tool steel, alloy steel, 17-4 PH, hardness-controlled parts | Target hardness, standard, and test location | Requires process confirmation before quote release |
| Finish specification | Cosmetic, corrosion, electrical, or wear requirements | Finish type, color, masking, thickness, sample needs | May require samples or supplier-specific review |
Upload drawings or notes that define certificate, hardness, and finish requirements before quote approval.
Material Selection Inputs
Function
Load, wear, corrosion, temperature, weight, and cosmetic requirements.
Process
Machining and printing have different material economics and design constraints.
Finish
Anodizing, passivation, polishing, and coating compatibility are checked before quoting.
Not Sure Which Material to Use?
Upload your CAD and use-case notes. Engineering will review material options before quoting.