Stainless Steel Surface Finish
No. 1 Stainless Steel Finish
Specifications, Supply & Technical Guide
No. 1 stainless steel finish is a hot-rolled, heat-treated / annealed and descaled or pickled surface used primarily for plate and heavy-gauge products where a smooth decorative appearance is not the main requirement. For procurement, specify the alloy, thickness, dimensions, No. 1 finish, roughness limits where needed, fabrication scope and surface acceptance criteria together.
Illustrative No. 1 Surface
NO. 1
Illustrative visual reference only. Actual No. 1 appearance can vary with grade, thickness, hot-rolling condition, annealing, descaling / pickling and mill practice. Use measurable requirements or an approved sample when visual consistency matters.
Finish Definition
What is a No. 1 stainless steel finish?
No. 1 is a hot-rolled stainless steel finish associated with annealing / heat treatment followed by descaling or pickling. The oxide scale is removed, but the resulting surface remains comparatively rough, dull and non-reflective.
This finish is commonly relevant to plate and heavier-gauge stainless products where mechanical properties, thickness, fabrication and service performance are more important than a decorative surface.
The No. 1 designation does not create a single universal Ra / Rz, gloss, color or visual-defect limit. Where those requirements matter, define them separately and verify them using an agreed test method or approved sample.
Specify more than “No. 1” when surface control matters
- Stainless steel grade and governing product standard
- Plate / sheet thickness, width, length and tolerances
- Required surface designation: No. 1
- Ra / Rz range when measurable roughness is critical
- Reflectivity / color tolerance where applicable
- Approved sample or finish-limit reference if appearance matters
- Surface protection, defect acceptance and cleaning requirement
Finish Evidence
Technical and application evidence for No. 1 finish approval
The page keeps the image count low: one technical evidence image and one application image in addition to the hero visual. Use verified production evidence before technical approval.
Technical evidence image
Use one combined image showing the actual No. 1 surface, sample panel and, where available, an Ra / Rz reading or finish-limit comparison.
Application image
Use one real plate, cut component or heavy-fabrication photo where the No. 1 stainless surface is relevant.
Supply Specification
No. 1 finish stainless plate, sheet and cut-part ordering matrix
Use this matrix to define the commercial information required for a usable quotation. Exact availability and dimensional limits should be confirmed against the actual grade, thickness and hot-rolled mill route.
Specify grade, thickness, width, length, tolerance, surface requirement and quantity.
Define dimensions, flatness, visible face and downstream processing requirements.
Provide drawings, tolerances, edge condition and final-surface expectations.
| Supply Form | Required Order Data | No. 1 Surface Control | Processing / Delivery Notes |
|---|---|---|---|
| No. 1 Plate | Grade, thickness, width, length, quantity and dimensional tolerance | No. 1 designation; add Ra/Rz, sample or defect limits when required | Confirm flatness, edge condition, surface protection and packaging |
| No. 1 Sheet | Grade, thickness, width, length, quantity and visible face | Hot-rolled, annealed and pickled / descaled surface with agreed acceptance criteria | Confirm cut-to-length and downstream fabrication requirements |
| Cut Blanks | Grade, thickness, blank size, quantity and drawing if applicable | Define whether the original No. 1 face must remain visible after cutting | Burr, edge, flatness and marking requirements should be stated in the RFQ |
| Fabricated Part | Drawing, grade, dimensions, quantity and final surface requirement | Define whether weld / forming zones will be reworked or further finished | Processing sequence should be agreed before production |
This table describes RFQ information only and does not represent live inventory. Confirm grade, thickness range and processing capability in the final quotation.
Finish Selection
No. 1 vs EN 1D vs 2D vs 2B stainless steel finish
Choose the finish according to the governing standard, hot-rolled versus cold-rolled route, surface roughness, thickness range, fabrication needs and final appearance.
| Finish | Visual Character | Production Character | Selection Logic | Specification Note |
|---|---|---|---|---|
|
ASTM No. 1
This Page |
Rough, dull, non-decorative | Hot rolled, annealed / heat treated and descaled | When ASTM No. 1 is specified for plate / flat product | Use governing ASTM requirements plus project-specific surface limits |
| EN 1D | Dull, rough, hot-rolled appearance | Hot rolled, heat treated and pickled / descaled | Comparable EN flat-product procurement context | Do not treat ASTM No. 1 and EN 1D as automatically identical |
| 2D | Dull but smoother than hot-rolled finishes | Cold rolled, heat treated and pickled | When a cold-rolled low-reflectivity surface is required | Product route differs from No. 1 |
| 2B | Smoother and moderately reflective | Cold rolled with final light skin pass | When a smoother general-purpose mill surface is preferred | Not a substitute where No. 1 hot-rolled finish is specified |
Processing Capability
Processing routes for No. 1 stainless steel
No. 1 material is commonly purchased for plate fabrication, so cutting, forming, welding and any later surface treatment should be defined as part of the RFQ.
Plate Cutting
Define dimensions, tolerances, heat-affected-zone and edge requirements.
Saw / Profile Cutting
Specify drawings, cut geometry and edge condition for prepared blanks.
Bending & Forming
Select the forming route according to grade, thickness and part geometry.
Welding
Define fabrication sequence and any post-weld cleaning or surface treatment requirement.
Surface Protection
Protection is project-specific for No. 1; specify it where the supplied face must be preserved.
Further Finishing
Define grinding, blasting, polishing or other downstream finish requirements separately.
Surface Control
Roughness, production route, visual tolerance and cleaning guidance
The content matrix requires unique, reviewable finish data. Do not publish invented Ra/Rz or supply values; replace project-specific visuals only with approved production or test information.
Ra / Rz & Production Route
No. 1 describes a hot-rolled, annealed / heat-treated and descaled surface, but it does not create one universal roughness limit for every mill, thickness or alloy.
- Ra target: specify when required
- Rz target: specify when required
- Measurement method: agree before inspection
- Route: hot rolled + annealed / heat treated + descaled
Reflectivity, Color & Defect Acceptance
No. 1 is generally dull and industrial in appearance, but exact tone and texture can vary with mill practice, alloy, thickness and descaling route.
- Use controlled-light comparison where appearance matters
- Approve a limit sample if tone / texture is critical
- Define scale-removal, stain and handling-mark criteria
- Do not assume batch-to-batch visual identity
Grades, Protection & Cleaning
Confirm compatible grades and dimensional range through the RFQ. Where No. 1 remains visible, define handling, contamination control and cleaning requirements appropriate to the application.
- Grade / form: confirm by quotation
- Protective film: only if specified and available
- Remove fabrication contamination using an approved method
- Use cleaners suitable for the stainless grade and final service
Application Guidance
Where is No. 1 stainless steel finish used?
No. 1 is most relevant where hot-rolled plate, heavier material or functional fabrication is more important than a smooth decorative surface.
Heavy Fabrication
Plate components and fabricated structures where the surface is functional rather than decorative.
Industrial Equipment
Frames, supports, covers and equipment components specified from hot-rolled stainless plate.
Process Equipment
Project-specific plate and fabricated components where grade, thickness and fabrication control dominate.
Structural Components
Hot-rolled stainless parts used where a decorative cold-rolled surface is unnecessary.
Cut Plate Parts
Profile-cut or machined blanks supplied for later welding, forming or assembly.
Further-Finished Components
Parts where No. 1 is an intermediate condition before grinding, blasting or another finish.
Standards & Equivalence
How No. 1 finish is specified for stainless steel flat products
The No. 1 designation should be combined with the correct material grade, product standard, dimensions, tolerances, surface acceptance and documentation requirements.
- ASTM A480 / A480M — No. 1 No. 1 is used for hot-rolled stainless flat products that are heat treated / annealed and descaled, producing a rough, dull industrial surface.
- EN 10088-2 — 1D comparison EN 1D occupies a similar hot-rolled, heat-treated and pickled / descaled flat-product context, but the governing standard should always be checked.
- Surface roughness Ra and/or Rz should be added as separate measurable acceptance criteria when the project needs tighter surface control than the finish designation alone provides.
- Visual acceptance Where tone, scale-removal quality or roughness matters, use an approved sample and agreed inspection conditions.
Do not use “No. 1” as the complete material specification.
The finish name does not define chemistry, mechanical properties, thickness tolerance, flatness or inspection documentation.
If roughness, scale-removal quality, color or appearance matters, add measurable criteria or an approved physical sample.
Do not automatically substitute EN 1D for ASTM No. 1 without checking the governing standard and required product route.
Technical FAQ
No. 1 stainless steel finish FAQ
What is a No. 1 stainless steel finish?
Is No. 1 stainless steel hot rolled or cold rolled?
What is the typical No. 1 surface roughness?
What is the difference between No. 1 and 2D stainless steel?
Is ASTM No. 1 the same as EN 1D?
Can No. 1 stainless steel be cut, formed and welded?
Does No. 1 stainless steel need protective film?
What information should be included in a No. 1 stainless steel RFQ?
Related Resources
Continue your stainless steel specification
Technical Evidence & Review
Data sources and document control for this No. 1 finish page
Required evidence sources
- Ra / Rz values should come from an actual measurement record or approved production test.
- The hot-rolled, annealing / heat-treatment and descaling route should match the applicable mill documentation.
- Visual tolerance should use controlled viewing and an approved / limit sample where required.
- Compatible grades, forms, protection and processing claims should match current quotation capability.
- Application images should be real project, production or permission-cleared evidence.
Document control
Technical Quote
Request a technical quote for No. 1 stainless steel
Send the grade, thickness, dimensions and No. 1 surface requirements together. Add any cutting, fabrication, roughness, sample or documentation requirements needed for the final quotation.
- Stainless steel grade
- Plate, sheet, blank or fabricated part
- Thickness × width × length
- Required quantity
- ASTM / project product standard
- No. 1 finish designation
- Ra / Rz or approved sample if required
- Cutting / fabrication / protection requirement
- Destination, due date and inspection needs