Automotive Parts Manufacturing – Machined, Cast & Molded
Automotive components manufactured across all three of our production lines: CNC-machined aluminum and steel brackets and shafts, die cast aluminum and zinc housings, and injection-molded interior and functional plastic parts. Prototypes to production with material documentation, dimensional reports and full batch traceability.
Free ConsultationCNC + Cast + Mold
Production Lines
3-5 Days
Prototype Lead Time
1 to 100k+
Volume Range
Full Batch Records
Documentation
Materials
| Grade | Properties | Typical Applications |
|---|---|---|
| Aluminum (AL6061-T6 / AL6063 / ADC12) | Machined aluminum for brackets, mounts and structural components; ADC12 cast aluminum for housings and complex shapes. Excellent strength-to-weight, readily anodized or coated, fully documented with mill test reports on stock material. | Brackets, mounting plates, sensor housings, battery tray components, lighting housings, trim mounts |
| Zinc (Zamak 3 / 5) & ZA Alloys | Fine-detail zinc castings with excellent dimensional stability and plating response – the standard for small precision automotive hardware where tight detail matters more than structural load. | Connector bodies, lock components, window hardware, cable gland bodies, decorative trim hardware |
| Engineering Plastics (PA66-GF30 / POM / ABS-PC) | PA66-GF30 for structural and underhood parts with heat and chemical resistance; POM for precision friction parts; ABS-PC for tough interior trim. All processed with documented drying and parameter control. | Interior trim, clips, ducting, sensor housings, connector bodies, cable management |
| Polypropylene (PP-TD20 / PP Homopolymer) | Impact-resistant polypropylene for interior and exterior trim, air ducts and fluid-path components; talc-filled grades for stiffness with good flow in thin walls. | Interior panels, air ducts, deflectors, trim clips, fluid reservoirs, underbody covers |
| Steel & Stainless (45# / SUS303 / 304) | Machined steel and stainless for load-bearing shafts, fasteners, valve components and hardware requiring strength, wear resistance or corrosion exposure. | Shafts, fasteners, valve components, brake hardware, exhaust-adjacent components, mounting hardware |
| Titanium (Gr2 / Gr5) | High-strength lightweight machining for performance, motorsport and specialty vehicle applications where weight savings justify material cost. | Motorsport brackets, fasteners, exhaust components, performance hardware |
Process Parameters
| Parameter | Standard Range |
|---|---|
| Dimensional Tolerance (Machined) | ±0.02mm standard; ±0.01mm on critical features |
| Dimensional Tolerance (As-Cast) | CT5-CT7 grade achievable with machining on functional faces |
| Dimensional Tolerance (Molded) | Per ISO 20457; ±0.05mm achievable on critical features |
| Geometric Tolerance | Position, flatness, perpendicularity to 0.02-0.05mm as specified |
| Surface Roughness (Machined) | Ra 1.6μm – 3.2μm; Ra ≤0.8μm with finishing pass |
| Volume Range | 1 piece prototype to 100,000+ annual volume |
| Prototype Lead Time | 3-5 days machined; 2-3 weeks cast/molded soft tooling |
| Production Tooling Lead Time | 4-6 weeks die casting / injection molds |
| Secondary Operations | Tapping, boring, insert molding, sub-assembly, torque assembly |
| Material Documentation | Mill test reports on stock material; batch records retained per production run |
Surface Finishes
As-Machined / As-Cast
Functional surfaces left as produced for internal components and interfaces that will be assembled without cosmetic requirements. The economical default for underhood and hidden applications.
Anodizing (Type II / III)
Anodizing for aluminum automotive parts: corrosion protection, wear resistance and color options. Type III hard coat for high-wear applications such as suspension hardware and moving interfaces.
E-Coat & Powder Coating
Electrophoretic coating reaching internal cavities, or polyester powder for external trim: corrosion protection with uniform appearance. Standard for brackets, housings and visible structural parts.
Plating (Zinc / Nickel / Chrome)
Plating of zinc castings and steel hardware for corrosion protection and appearance – chrome for decorative trim hardware, zinc for fasteners and underbody components.
Chromating & Passivation
Chemical conversion coatings for aluminum and zinc castings as corrosion-protection bases; passivation for stainless components after machining.
Textured & Painted Plastics
Mold-textured plastic trim with matching paint systems for interior and exterior components; texture and gloss grades specified per your master sample.
Design for Manufacturing (DFM)
- Mark critical-to-function dimensions explicitly and leave the rest at general tolerance – automotive drawings mix both constantly, and machining the whole drawing to tight tolerance wastes budget that belongs on the functional interfaces
- Design for the manufacturing route from the start: cast housings with machining allowances on sealing faces, machined brackets from standard bar and plate, molded parts with uniform walls and draft
- Keep machined sealing faces away from casting gate zones and last-fill corners where porosity concentrates – we will mark risk zones on the casting drawing during DFM
- For molded automotive plastics, specify uniform wall thickness and generous draft; glass-filled PA66 flows less freely and needs bigger radii and gates than unfilled resins
- Choose materials for the environment: underhood parts need heat resistance (PA66-GF30, PPS-family, aluminum), exterior parts need weathering (ASA/PC, powder coat), interior parts balance gloss, scratch and VOC behavior
- Design threaded interfaces with insert molding or post-molded tapping rather than threads cut into unsupported plastic walls
- Plan assembly sequence where components mate: stack-up analysis on mating machined and cast parts prevents forced assembly on your line
- Specify traceability requirements early: serial, lot or batch tracking changes documentation setup, not the part – but retrofitting it is painful
- For prototype programs, use production-intent materials where possible so test results transfer: an aluminum prototype validates an aluminum production part better than a printed one
- Send STEP plus a marked-up 2D drawing; our free DFM review returns within 24 hours with process route recommendations, tolerance notes and cost drivers
Tooling & Capacity
| Type | Lead Time | Suitable For |
|---|---|---|
| CNC Prototype Machining (No Tooling) | 3-5 days | Brackets, shafts, housings and any machined geometry in 1-10 pieces for design validation and bench testing |
| Die Casting Tools (Aluminum / Zinc) | 4-6 weeks | Production housings, valve bodies, brackets and complex shapes; prototype dies from 2-4 weeks for 100-500 piece pilots |
| Injection Molds (Steel / Aluminum) | 3-4 weeks aluminum soft tool; 5-7 weeks steel | Interior trim, clips, ducting, sensor housings and functional plastic parts; soft tooling for pilot and market-test quantities |
| Machining Fixtures & Assembly Jigs | 1-2 weeks | Repeatable secondary machining of castings and torque-controlled sub-assembly for volume programs |
Quality Assurance
- Incoming material verification with mill test reports documenting chemistry and mechanical properties on all metal stock
- First Article Inspection with full dimensional report on the first part of every production batch, before the run continues
- In-process dimensional checks at defined stages, with process adjustments recorded per batch
- CMM measurement on critical features; geometric tolerance verification (position, flatness, perpendicularity) where specified
- Surface roughness verification by profilometer on functional surfaces
- Porosity surveillance on castings: visual and sectioned-sample checks on pressure-critical parts; leak testing where specified
- Torque verification with calibrated tools on assembled joints, with recorded values
- Batch traceability: material lot, tool number, process parameters and inspection results retained per production run
- Final dimensional report with measured values shipped with every batch; retained samples kept for reference
- Dimensional capability studies maintained on critical dimensions for volume programs
Applications
- Powertrain and drivetrain: brackets, housings, shafts, spacers, sensor bodies, valve components
- Interior and trim: trim clips, panels, ducting, knobs, grips, decorative hardware, mounting brackets
- Electronics and electrical: connector bodies, sensor housings, shielding components, cable management
- Lighting: lamp housings, reflector frames, brackets, heat sink bodies, mounting hardware
- EV and hybrid: battery tray components, charging hardware, housings, thermal management parts, cable routing
- Chassis and suspension: machined brackets, bushings, mounting hardware, wear components
- Aftermarket and performance: replacement hardware, motorsport brackets, performance fasteners, custom components
- Commercial vehicle and specialty: control boxes, hardware assemblies, mounting systems, body hardware
Why Choose FHY Precision
Three processes, one supplier: machining, die casting and injection molding in-house – brackets, housings and plastic trim come from one quality system with one accountable schedule
Prototype to production continuity: the same files, materials and team that make your 3-day prototypes run your production tooling; no re-learning, no re-qualification
Documentation discipline: mill test reports, FAI dimensional reports, in-process records and batch traceability retained per run – your quality file is built as we produce, not reconstructed later
Process route honesty: we recommend machining, casting or molding per part function – including when machining beats casting for your quantity
Cast plus machined capability: housings cast to near-net shape with machined sealing faces, bores and bolt patterns, in one supply chain with datum and allowance designed together
Material breadth: aluminum, zinc, steel, stainless, titanium, PA66-GF30, POM, ABS-PC, PP and more – with established parameters per material family
Volume flexibility: from single prototypes and 100-piece pilots to multi-cavity production at 100,000+ annual volume
DFM across processes: casting drawings reviewed for porosity and allowance, molded parts for wall and draft, machined parts for stock and setups – before tooling starts
FAQ
1. What automotive parts do you manufacture?
Brackets, housings, shafts, spacers, sensor bodies, connector bodies, trim components, ducting, lighting hardware, battery and charging components – across machining (aluminum, steel, stainless, titanium), die casting (aluminum ADC12, zinc Zamak) and injection molding (PA66-GF30, POM, ABS-PC, PP). If it is a mechanical or structural component in those material families, we can make it.
2. What volumes can you support?
From single prototypes (no tooling, 3-5 days) through 100-500 piece pilot runs with soft tooling, to multi-cavity production at 100,000+ annual volume. We do not force you into production tooling before your design is proven, and we do not quote prototype pricing as if it were production.
3. How do you handle quality documentation for automotive work?
Every batch ships with a dimensional report of measured values. Mill test reports document material chemistry and mechanical properties on all metal stock. First Article Inspection, in-process records, process parameters and batch traceability are retained per run. If your program needs specific documentation formats – capability studies, control plans, sampling plans – tell us the format and we will produce to it.
4. What documentation can you provide for automotive programs?
Every batch ships with a dimensional report of measured values. Mill test reports document material chemistry and mechanical properties on all metal stock. First Article Inspection reports, in-process inspection records, process parameters and batch traceability are retained per run, and dimensional capability studies are maintained on critical dimensions for volume programs. If your customer requires a specific submission format – control plans, sampling plans, capability studies – tell us the format during quoting and we will produce to it.
5. Can you support prototype builds for automotive programs?
Yes – machined prototypes in 3-5 days with no tooling, and soft-tooling cast or molded pilots in 2-3 weeks. We recommend production-intent materials where possible so bench and validation testing transfers to the production part. Prototype programs often run through several iterations; there is no tooling to modify, so revisions are quick.
6. What materials do you recommend for underhood applications?
Underhood means heat and chemicals: PA66-GF30 for structural plastic parts (continuous service around 120-150°C), aluminum ADC12 or 6061 for housings and brackets, and stainless where corrosion exposure is severe. We avoid standard ABS and unprotected steel in underhood locations and will propose alternatives during DFM if your drawing specifies them.
7. Can you machine die cast automotive parts to final tolerance?
Yes – cast-plus-machined is one of our core capabilities. Castings are produced with designed-in machining allowances, then sealing faces, bores and bolt patterns are machined to ±0.02mm with dedicated fixtures. Datum selection and allowance are designed with the casting tool, so functional faces clean up reliably batch after batch.
8. How do you control porosity in cast automotive parts?
Porosity is managed by design and process: gate and runner layout that fills sequentially, die temperature control, and DFM that keeps machined sealing faces away from last-fill corners and thick-to-thin transitions. Pressure-critical castings are leak-tested; structural castings can be X-rayed or sectioned on a sampling plan. We mark the porosity risk zones on your drawing before tooling.
9. Do you work with automotive customers directly or only through tier suppliers?
Both. We supply tier-1 and tier-2 assembly programs and also work directly with OEM engineering teams on prototype and low-volume components. Whichever your structure, the manufacturing process and documentation are the same.
10. What about EV and new-energy components?
Battery tray brackets and machining, charging hardware and housings, thermal management components, cable routing hardware and sensor bodies are active program areas across our machining and casting lines. Aluminum and PA66-GF30 dominate these applications; we quote titanium and specialty materials case by case.
11. Can you assemble automotive sub-assemblies?
Yes – sub-assembly with torque-controlled fastening, press-fit and adhesive bonding, with functional testing and packaging per your requirement. Machined, cast and molded components all come from our own lines, so assembly stays in one quality chain with full traceability.
12. What lead times should I plan for?
Machined prototypes: 3-5 days. Soft-tooling pilots (cast or molded): 2-4 weeks. Production tooling: die casting 4-6 weeks, injection molds 5-7 weeks, with trial and reference-sample approval adding about a week. Production batches run 2-4 weeks depending on quantity and secondary operations. All dates are confirmed in writing with the quotation.
13. What documentation comes with automotive parts?
Our standard package includes material certificates traceable to heat number, dimensional inspection reports against your drawing, first article inspection reports for new part numbers, process records for the production run, and lot traceability linking shipped parts back to material and process data. Where your program requires a formal submission package – first article reports, control plans, process flow documentation, capability data on critical dimensions – we assemble the underlying evidence and format it to your customer's requirements. Tell us the documentation scope during quoting so it is agreed up front, not discovered at launch.
14. Do you support IMDS entries?
Yes, on request. IMDS (International Material Data System) entries connect each component with its declared material composition – increasingly a gate requirement for automotive OEM programs. We compile the substance data for the materials and finishes we supply, including purchased sub-components where we are turnkey, and file or hand over entries in the format your customer system expects. For multi-supplier assemblies, we flag which declarations are ours and which remain yours to complete, so gaps surface before submission deadlines rather than after.
15. What is the difference between FAI and a full documentation submission?
FAI (First Article Inspection) is a physical verification event: the first parts off the tool are measured against the drawing and the results documented – ballooned drawings, dimensional layout on multiple samples per cavity, material certifications, capability data on critical features. A formal documentation submission is the broader package that customer quality departments specify, which can include the FAI results plus process flow, control plans and warrants. Confusing the two is how gaps appear: FAI proves the parts; the full package proves the system that makes them. We produce the underlying evidence for both.
16. How do you handle material traceability from heat to shipment?
Every shipment links back through the chain: material certificate with heat number, lot records for that production run, inspection data against the lot, and shipping records identifying which lots went into which cartons. If stainless steel or alloy changes between shipments, the records show it. This is not paperwork theater – when a field issue appears eighteen months later, traceability is what lets us answer 'which parts, which material, which process window' with data instead of estimates. Ask for sample records from a comparable past order during vetting; a shop with real traceability has them.