1. What is SUS304 No.1?Hot rolling → Annealing → Pickling
Meaning of SUS304 No.1 in the CNC Precision Machining Industry
In the CNC precision machining industry, SUS304 No.1 represents not only a material specification, but also an important indication of raw material condition, machining strategy, and cost efficiency.
For manufacturers producing mechanical components, semiconductor equipment parts, or industrial structures, SUS304 No.1 plays a fundamental role as the starting material for machining processes.
1. What is SUS304 No.1?Hot rolling → Annealing → Pickling
1. What is SUS304 No.1?Hot rolling → Annealing → Pickling
SUS304 No.1 refers to:
Material grade
SUS304
Surface finish
No.1 finish
The No.1 finish is produced through the following process:
Hot rolling → Annealing → Pickling
Typical characteristics include:
- Rough matte surface appearance
- Grayish-white industrial surface texture
- Non-decorative finish
- Retains the natural hot-rolled surface pattern
Key characteristics
| Property | Description |
|---|---|
| Surface texture | Rough matte |
| Production method | Hot-rolled |
| Typical thickness | Medium to heavy plate |
| Cost | Lower compared to finished surfaces |
| Suitability | Ideal for machining stock |
2. Significance of SUS304 No.1 in CNC Machining
Raw Material for Machining
In the CNC machining industry, No.1 material is commonly used as raw stock material.
Since CNC machining removes surface layers during cutting operations, decorative surfaces are unnecessary.
Therefore, manufacturers often select No.1 plates because:
- Surface finish is not required
- Machining removes outer layers
- Material thickness is preserved for cutting operations
In industrial practice:
SUS304 No.1 = Standard raw material for machining
Cost Efficiency in Manufacturing
Using finished surfaces such as:
- 2B
- BA
- HL
would increase material cost without providing benefit, because the surface layer will be removed during CNC machining.
Therefore:
Machined components typically start with No.1 material.
Advantages include:
- Lower material cost
- No waste of finished surface treatment
- Ideal for large-scale CNC production
Suitable for Structural and Heavy Components
No.1 finish is commonly available in thicker industrial plates, making it suitable for machining structural components.
Typical plate thicknesses include:
6 mm
10 mm
20 mm
50 mm or more
Typical CNC-machined components include:
- Mechanical base plates
- Semiconductor equipment structural parts
- Fixtures and jigs
- Flanges
- Machine brackets
3. Role in Semiconductor Equipment Manufacturing
In semiconductor equipment manufacturing, companies such as:
- ASML
- Applied Materials
- Lam Research
often use SUS304 No.1 material as the initial stage of component manufacturing.
Typical process flow:
SUS304 No.1 plate
↓
CNC rough machining
↓
CNC precision machining
↓
Surface finishing processes such as:
- Electropolishing
- Sandblasting
- Hairline finishing
- PVD coating
- Chemical passivation
The No.1 surface therefore represents the starting point of the manufacturing process rather than the final surface condition.
4. Engineering Considerations in CNC Machining
From an engineering perspective, SUS304 No.1 implies several machining considerations.
Machining allowance
Due to the rough hot-rolled surface, machining allowance is required.
Typical allowance:
1–3 mm material removal.
Removal of oxide scale
Hot-rolled materials may contain:
- Oxide scale
- Uneven surface hardness
Therefore, rough machining is necessary to remove the outer layer.
Cutting tool selection
Typical tooling for SUS304 machining includes:
- Carbide end mills
- TiAlN coated tools
This helps prevent work hardening, which is common when machining austenitic stainless steels.
5. Comparison with Other Stainless Steel Surface Finishes
| Surface Finish | Process | Typical Application |
|---|---|---|
| No.1 | Hot rolled | CNC machining raw stock |
| 2B | Cold rolled | General industrial parts |
| BA | Bright annealed | Decorative applications |
| HL | Hairline finish | Equipment exterior panels |
In CNC manufacturing:
No.1 finish is the most common starting material for machining operations.
Yongyi Technology Co., Ltd.
location_on 42756 No. 188-9, Section 1, Dafeng Road, Tanzi District, Taichung City, Taiwan
email yongyi-sales@umail.hinet.net
email justinwu6767@gmail.com