| Stainless Grade | Category | Machinability | Corrosion Resistance | Hardness | Magnetic |
|---|---|---|---|---|---|
| 304 | Austenitic | ★★★☆☆ | ★★★★☆ | ★★☆☆☆ | No |
| 316L | Austenitic | ★★★☆☆ | ★★★★★ | ★★☆☆☆ | No |
| 303 | Austenitic | ★★★★★ | ★★★☆☆ | ★★☆☆☆ | No |
| 17-4 PH | P.H. Steel | ★★☆☆☆ | ★★★★☆ | ★★★★★ | Yes |
| 430 | Ferritic | ★★★★☆ | ★★★☆☆ | ★★★☆☆ | Yes |
| 420 | Martensitic | ★★★☆☆ | ★★☆☆☆ | ★★★★★ | Yes |
| 2205 | Duplex | ★★☆☆☆ | ★★★★★ | ★★★★☆ | Yes |
Stainless Steel CNC Machining Services & Custom Metal Parts
We offer manufacturing services for your stainless steel parts, supporting turning and multi-axis machining. From drawing design to design feedback, we provide fast responses within two hours. Contact our professional engineers now to ease your worries.
100+
CNC Machines
3-7 Day
Typical Lead Time
24hr
Rapid Quoting
6k㎡
Factory Area.
Dimensional Tolerance
±0.005mm
Achieved through high-end Japanese/German machining centers and CMM verification.
Surface Roughness
Ra ≤ 0.8μm
Meets stringent requirements for optical components and high-end consumer electronics.
Quality Assurance
ISO 9001:2015
Rigorous 100% inspection protocols for critical features using automated OMM/CMM equipment.
Materials for stainless steel parts
Our Stainless Steel Material Stock
Select and understand the right stainless steel materials to reduce project development costs.
Stainless Steel 304
Universal Corrosion Resistance
Stainless Steel 316L
Marine & Medical Grade
Stainless Steel 303
High Machinability Standard
17-4 PH Stainless
Precipitation Hardened Strength
Stainless Steel 430
Ferritic Decorative Finish
Stainless Steel 420
High Hardness Martensitic
Duplex 2205
Extreme Chemical Resistance
Sample Gallery
CNC Stainless Steel Parts prototyping
Explore the prototype parts we have produced. With strong solution capabilities, we deliver high-quality precision stainless steel parts for various industries.
Stainless Steel Turned Parts
Stainless Steel Cylindrical Manifold
Threaded Fitting -Bushing
End Ring - Split Bushing
Our Capabilities
Custom CNC Machined Stainless Steel Processes
Explore our comprehensive manufacturing processes for stainless steel components, showcasing our expertise in delivering industry-compliant solutions across diverse sectors.
CNC Milling
Multi-axis milling for complex geometries, cavities, contours, and surface features. Our 3-axis, 4-axis, and 5-axis machines handle parts of any complexity.
- Max size: 40 in x 20 in x 20 in
- Milling Tolerance: ±0.001 in
- Surface Finish: Ra 32 μin
CNC Turning
Precision lathes for machining rotational parts including shafts, bushings, connectors, and fittings. Live tooling enables complex features in a single setup.
- Diameter: 0.1 in - 12 in
- Live Tooling Capability
- Sub-Spindle Options
5-Axis CNC Machining
Tackle the most complex geometries with full 5-axis simultaneous machining. Complete parts in a single setup, reducing manual handling and increasing accuracy.
- Intricate Features
- Impellers & Turbines
- Aerospace Components
Surface Finishing
Enhance the aesthetic, corrosion resistance, and functional properties of your stainless steel parts with a range of post-machining finishes.
- Passivation (ASTM A967)
- Electropolishing
- Brushed & Mirror Polishing
- Sandblasting
Quality Inspection
Rigorous quality control processes ensure every part meets your precise specifications and industry standards, from material verification to final dimensional checks.
- CMM Inspection
- First Article Inspection (FAI)
- Material Certifications
- Dimensional Reports
Our Facility
Rapid Model CNC Machining Center
Rapid Model is a supplier equipped with advanced machinery. Our factory can deliver high-standard stainless steel parts for your most demanding projects.
3-Axis CNC Milling Machines
CNC Turning-Milling Centers
CNCTapping Center
Vertical Machining Center
Heavy-Duty Horizontal Lathe
High-Precision CNC Turning Center
Trunnion-Type 5-Axis VMC
5-Axis Gantry Machining Center
Material Selection Guide
Stainless Steel Alloy Properties Comparison
Comparison of Austenitic, Martensitic, Ferritic, Duplex, and Precipitation Hardening stainless steels to optimize your CNC project requirements.
- Performance Comparison
- Mechanical Properties
- Surface Treatment
- Design Expertise
| Stainless Grade | Tensile Strength (MPa) | Hardness (HB/HRC) | Core Advantages |
|---|---|---|---|
| 304 / 316L | ≥ 515 | ~180 HB | Excellent formability and weldability; 316L offers superior pitting resistance. |
| 303 | ≥ 500 | ~190 HB | Free-machining grade designed for high-speed CNC production of nuts and bolts. |
| 17-4 PH | ≥ 1100 | 30 - 45 HRC | High strength-to-weight ratio. Maintains corrosion resistance while being heat-treatable. |
| 2205 | ≥ 620 | ~290 HB | Double the strength of austenitic steels with extreme resistance to stress corrosion cracking. |
| 420 / 430 | ≥ 450 - 700 | Up to 50 HRC (420) | 430 is for cost-effective decorative use; 420 is for high-hardness cutting tools. |
| Stainless Grade | Passivation | Electropolishing | Mirror Polishing | Best Use Case |
|---|---|---|---|---|
| 304 / 316L | Superior | Superior | Excellent | Medical devices & Sanitary fittings |
| 303 | Good | Fair | Good | Precision turned hardware |
| 17-4 PH | Excellent | Good | Fair | Aerospace & Valve components |
| 2205 | Excellent | Great | Fair | Chemical & Marine industrial parts |
| 400 Series | Standard | Fair | Good | Home appliances & Cutlery |
| Design Factor | General Spec | Precision Limit | Engineering Recommendation |
|---|---|---|---|
| Machining Allowance | +0.5 mm | +0.1 mm | Ensure enough depth of cut to stay below the work-hardened layer of 300-series steels. |
| Hole Depth | ≤ 3x Dia | ≤ 5x Dia | Peck drilling is mandatory for 316L and 2205 due to toughness and heat generation. |
| Thread Specs | 6H / 2B | 4H / 3B | Use roll taps for 304/316L to increase thread strength and tool life. |
Austenitic (304/316L/303): Non-magnetic and highly corrosion-resistant. 303 is the king of machinability, while 316L is the standard for marine/medical use.
Precipitation Hardening (17-4 PH): Combines the best of 300 and 400 series. High strength after aging treatment with excellent stability.
Duplex (2205): A mixed microstructure of austenite and ferrite. It provides significantly higher strength and superior resistance to chloride-induced stress corrosion.
Martensitic & Ferritic (420/430): Magnetic steels. 420 is heat-treatable to high hardness (HRC 50+), while 430 offers good resistance to atmospheric corrosion at a lower cost.
Technical Expertise
Stainless Steel CNC Machining: Challenges & Solutions
- Medical Devices
- Aerospace
- Oil & Gas
- Semiconductor
Project Specs
- MaterialSS 316L (Medical Grade)
- SurfaceElectropolished Ra 0.2μm
- FeatureThin-walled Micro Cavities
Surgical Endoscope Housing Precision Turning
The Technical Challenge
316L stainless steel is prone to severe work hardening. During the machining of 0.5mm thin walls, tool pressure often causes part deflection and vibration. Furthermore, the internal cavities required a mirror-like finish (Ra 0.2μm) to prevent bacterial adhesion, which is difficult to achieve with standard cutting tools.
Our Engineering Solution
We utilized Swiss-type CNC lathes to provide maximum support near the cutting point, preventing deflection. By implementing specialized cermet inserts with a high rake angle, we minimized heat transfer to the workpiece. Post-machining, a multi-stage electropolishing process was applied to reach the surgical-grade Ra 0.2μm finish without altering critical dimensions.
Ra 0.2 μmSurface Finish
±0.005 mmOD Tolerance
BiocompatiblePassivated
Project Specs
- Material17-4 PH Stainless (H1025)
- Hardness35-38 HRC
- RequirementZero-Distortion Geometry
High-Pressure Hydraulic Actuator Valve
The Technical Challenge
17-4 PH in the H1025 condition is highly abrasive, leading to rapid tool wear and fluctuating dimensions. The primary challenge was maintaining the strict perpendicularity of deep internal bores while managing the high cutting forces required to penetrate the hardened material without causing micro-cracking.
Our Engineering Solution
We employed solid carbide drills with specialized AlTiN coatings to handle the HRC 35+ hardness. A trochoidal milling strategy was used for the external profiles to keep tool load constant. To ensure zero distortion, we performed a secondary stress-relief cycle between roughing and finishing passes, ensuring the part remained stable even under extreme hydraulic pressure.
0.01 mmPerpendicularity
38 HRCFinal Hardness
High-CycleFatigue Life
Project Specs
- Material2205 Duplex Stainless
- EnvironmentCorrosive Seawater
- PrecisionLarge Diameter Threading
Subsea Flow Control Valve Body
The Technical Challenge
Duplex 2205 has double the yield strength of austenitic grades. Its high toughness makes chip breaking extremely difficult, often resulting in "bird-nesting" that can damage the surface or break tools during internal threading. Managing heat dissipation in this low-thermal-conductivity material is also critical.
Our Engineering Solution
We utilized 70-bar high-pressure coolant through the tool to break chips instantly. For the large-diameter threads, we implemented a multi-pass custom threading cycle with chip-breaking pauses. By using indexable inserts with a dedicated "duplex" geometry, we increased tool life by 40% while maintaining a consistent Ra 0.8μm sealing surface.
Ra 0.8 μmSealing Face
ZeroPitting Defect
100%Pressure Tested
Project Specs
- Material316L VAR (Vacuum Arc Remelt)
- Vacuum GradeUHV (Ultra-High Vacuum)
- Tolerance±0.005mm Profile
UHV Gas Distribution Manifold
The Technical Challenge
Semiconductor applications require ultra-high purity. Even the smallest burr or metallic contamination from a tool can ruin a vacuum chamber's performance. The manifold featured complex internal cross-holes where manual deburring was impossible, yet every edge had to be perfectly radiused to prevent gas entrapment.
Our Engineering Solution
We used specialized abrasive flow machining (AFM) after CNC milling to deburr internal intersections. All machining was done using oil-free synthetic coolants to prevent hydrocarbon contamination. The final parts underwent a 12-hour ultrasonic cleaning process in a Class 1000 cleanroom environment before vacuum-sealed packaging.
UHVReady
0.005 mmProfile Acc.
CleanroomCertified
Customer Voice
Feedback from Our Global Partners
Reliable results in precision CNC aluminum machining across aerospace, medical, automotive, and electronics sectors.
★★★★★
The dimensional consistency on the 6061-T6 manifold blocks is impressive. We verified the internal bore tolerances with our CMM, and every part in the batch fell well within our ±0.01mm requirement. No burrs found in the cross-drilled intersections.
★★★★★
Highly professional engineering feedback. Their team suggested a slight modification to the corner radii which reduced tool chatter and improved the surface finish on the thin-wall sections. Final parts look great and the assembly fit is perfect.
★★★★★
The anodized finish on our electronic enclosures is exceptionally uniform. No racking marks visible and the color matching across different batches is consistent. Great communication and the parts were packed securely for air freight.
★★★★☆
Excellent execution on a complex 5-axis impeller project. The organic blade profiles were smooth with no visible tool steps. Lead time was slightly tight, but the quality of the final aluminum component made up for it. Will order again.
★★★★★
Reliable partner for fast-turnaround prototyping. We received our 50-piece order of CNC turned shafts in France within 10 days. The threads were clean and the concentricity was spot on. Very fair pricing for this level of precision.
★★★★★
Superior Swiss machining for our miniature connector pins. Managing tolerances of ±0.005mm on such small aluminum parts is difficult, but they delivered 98% compliant parts. Material certificates provided as requested.
★★★★☆
Structural integrity was critical for our subsea housing. They delivered the parts in perfect condition; the shipment was delayed due to customs issues, but delivery timelines were communicated proactively and the issue was resolved quickly.
★★★★★
The attention to detail on the optical mounting bracket was exceptional. The black hard anodized finish also met our expectations, which is critical for our laser applications.
For Reference Only
Online CNC Machining Quote Estimation
- Pricing Estimate
- Surface Roughness
- Weight Calculation
Pro Manufacturing Quote Calculator (v3.5 - Ultra Precision)
01. Material & Dimensions
02. Processing & Order Details
* Standard Margin
ESTIMATED TOTAL ORDER AMOUNT
$0.00
Tol(0.5) + Mat(0) + Size(0) = 0.5h
Machining Fee/Pc: $0.00
Total Material: $0.00
Total Profit: $0.00
Surface Roughness Unit Converter
Enter a value in any field to convert between scales (Metric and Imperial).
Note:
The conversion between Ra and Rz is an approximation ($Rz \approx 4 \times Ra$) as they measure different profile characteristics. Calculations are based on ISO 4287 standards.
Weight (g) = (L × W × H / 1000) × Density
Calculated Result
0.00g
Efficient Collaboration Process
Custom CNC Stainless Steel Parts
Get your parts to market faster with our streamlined, high-efficiency production process. We handle the complexity so you can focus on scaling your brand.
01
Quote & DFM
Upload STP/DXF files for instant pricing and manufacturability analysis.
02
Design Optimization
Our engineers refine the design for cost-efficiency and production speed.
03
Precision Fabrication
Advanced Equipment & Expert Engineering.
04
Quality Validation
CMM verification and ISO 9001 standardized inspection protocols.
05
Finish & Delivery
Final surface finishing, assembly, and global logistical dispatch.
FAQ
Addressing Your Concerns
-
What surface finishes are available after aluminum CNC machining?
Available finishes include anodizing (clear, black, color), hard anodizing (Type III), bead blasting, brushing, powder coating, painting, and electroplating. Selection depends on corrosion resistance, wear resistance, appearance, and functional requirements.
-
Which industries use aluminum CNC machining?
Aluminum CNC machining is widely used in aerospace, medical devices, electronics, telecommunications, robotics, optical and laser systems, automotive, and new energy industries.
-
Does anodizing affect dimensional accuracy?
Yes. Anodizing adds an oxide layer typically 5–25 μm thick, with about 50% growing inward and 50% outward. Dimensional compensation or masking is applied to critical features to maintain tight tolerances.
-
Does aluminum CNC machining comply with ISO 2768 or ASME standards?
Yes. Aluminum CNC machining commonly follows ISO 2768-m/f for general tolerances and ASME Y14.5 for GD&T, unless otherwise specified on the drawing.
-
Which aluminum alloy is best for CNC machining?
6061 is the most commonly used alloy due to its excellent machinability and cost-performance. Other options include 7075 for high strength, 2024 for fatigue resistance, 5052 for corrosion resistance, and 6063 for better surface finish and thermal conductivity.
-
What aluminum machining services and milling solutions are available?
Services include 3-axis to 5-axis CNC milling, CNC turning, mill-turn machining, rapid prototyping, low-volume and batch production, DFM optimization, and surface finishing.
-
Can sheet metal fabrication be combined with aluminum CNC machining?
Yes. Sheet metal fabrication and aluminum CNC machining can be combined to produce complete assemblies such as enclosures, frames, and structural modules, improving consistency and reducing lead time.