Guide to Stainless Steel Surface Finishes in Custom Fabrication
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Stainless steel finish directly impacts both the performance and aesthetics of any custom fabricated component. Many options are available to cover the wide range of applications where stainless steel is used. The right finish helps turn raw sheet metal into components ranging from kitchen prep tables and electronics enclosures to decorative elevator panels and other architectural features. The best finish for any particular project depends on its functional, environmental, and aesthetic demands.
Mill Finishes
Mill finishes are essentially untreated raw surfaces. They are used when material functionality and structural integrity are more important that aesthetics.
- 1 Finish (Hot Rolled) – dark, rough, and unpolished. Hot-rolled finishes are used in a variety of products including structural components, industrial tanks, heavy equipment, and other uses where surface appearance is not that critical.
- 2 Finish (Cold-Rolled) – smooth, with a grey, slightly reflective finish. Cold-rolled is ideal for industrial products such as processing equipment, chemical vats, and also found in solar panels.
- No 2D Finish – a dull, non-reflective matte finish. It’s common in automotive exhaust systems and fuel tanks, industrial roofing, appliance components, HVAC ductwork, structural framing, and agricultural equipment including grain silos.
Mechanical/Directional Finishes
Directional stainless steel finishes are created by grinding the surface with abrasive belts. This process creates predictable line patterns that offer an appealing aesthetic, while helping to hide wear and tear.
- 3 Finish (Intermediate Ground) – has a course unidirectional grain which is created using a 100-120 grit abrasive. No. 3 is often used in kitchen equipment and architectural accents that require a semi-finished look.
- 4 Finish (Architectural/Satin) – this is the most recognizable finish that features a fine, parallel linear grain that reduces glare and masks fingerprints. No 4. is found in commercial kitchen appliances, elevator interiors and escalators, medical equipment, and architectural cladding.
- 6 Finish (Satin/Velvet) – a soft and dull finish that is produced by Tampico brushing, a specialized process that uses stiff heat-resistant Agave lechuguilla plant fibers. It’s often used in architectural panels where low reflectivity is required. It’s also ideal for applications that need smooth and cleanable surfaces such as medical and lab equpiment.
High-Polish/Mirror Finishes
High-polish finishes are achieved by multi-stage buffing . which removes scratches and results in a highly reflective surface. Mirror finishes are best for applications that require high visual impact or extreme cleanability.
No. 7 Finish – highly-reflective with faint grit lines. Typically used in decorative trim, retail displays, ornamental railings, and other high-impact architectural features.
No. 8 Finish (Mirror Finish) – the brightest, defect-free finish with a mirror-like surface that is produced by a combination of extensive buffing and chemical polishing. Mirror finish is ideal for cleanroom equipment, pharmaceutical applications, decorative architecture, wall mirrors and specialty applications such as high-precision optical reflectors.
Specialized Stainless Steel Finishes
In addition to standard finishes, specialized ones are also available. Rather than mechanical processes, these are achieved using chemical, electrochemical, or bead blasting processes. Specialty finishes are used when functional requirements call for characteristics such as micro-smoothness or non-directional uniformity.
Stainless Steel Surface Finish Specification & Selection Chart
| Finish | Finish Name / Process | Appearance & Texture | Cleanability | Scratch Masking | Typical Applications | |
|---|---|---|---|---|---|---|
| No. 1 |  | Hot-Rolled | Dark, rough, scaled | Low | N/A (Rough) | Structural beams, industrial tanks, heavy weldments |
| No. 2B |  | Cold-Rolled (Standard) | Smooth, matte gray, mild sheen | Moderate | Low | Industrial vats, chemical processing, base sheet metal |
| No. 2D |  | Cold-Rolled (Dull Matte) | Dull, non-reflective matte | Moderate | Low | Deep-drawn parts, exhaust systems, industrial roofing |
| No. 3 |  | Intermediate Ground | Coarse, linear grain (100–120 grit) | Moderate | High | Kitchen equipment, semi-finished structural trim |
| No. 4 |  | Architectural / Satin | Fine, parallel linear grain | Good | High | Commercial kitchen tables, elevator cabs, hospital gear |
| No. 6 |  | Satin / Velvet (Tampico) | Soft, dull, low-glare satin | High | Moderate | Architectural panels, low-reflection food/lab fixtures |
| No. 7 |  | High-Polish / Semi-Mirror | Highly reflective, faint grit lines | High | Low | Decorative trim, store displays, ornamental railings |
| No. 8 |  | Mirror Finish | Mirror-like, zero visible grain | Very High | Low | Cleanrooms, pharmaceutical vessels, high-end mirrors |
| Electropolished |  | Electrochemical | Ultra-smooth, high-gloss micro-finish | Superior | Low | Medical devices, pharmaceutical piping, marine hardware |
| Bead Blasted |  | Media Blasted (Glass/Sand) | Uniform, non-directional matte | Moderate | Superior | Hiding scratches, reducing glare, paint prep |
| BA |  | Bright Annealed | Highly reflective, smooth mirror-like finish | High | Low | Appliance trim, automotive trim, surgical instruments, cleanrooms |
| Custom / Embossed |  | Textured / Rigidized | Patterned 3D tactile surface texture | Varies | Varies | High-traffic elevator interiors, kick plates, anti-slip flooring |