Picking the wrong square tube costs money, time, and trust. Specs can be confusing, and finishes look different on site. Here’s a clear, practical guide to help you choose the right 304 stainless steel square tube the first time.
Answer in brief: 304 stainless steel square tubing is a hollow stainless steel square section made from Type 304 stainless. It combines high strength-to-weight performance with excelente resistência à corrosão and clean lines for estrutural e ornamentais projects. It is easy to cut, solda, and finish, comes in many tamanho e espessura da parede options, and is widely available from global suppliers.
Stainless steel square tube is a hollow profile with four equal sides and a crisp corner radius, engineered for clean looks and dependable performance. The term stainless steel square generally refers to this square-section tubos de aço made from corrosion-resistant alloys.
Grau 304 is the workhorse. It offers reliable formabilidade and balanced strength, along with excelente resistência à corrosão in most fresh water and many mild acidic settings. Because 304 is widely produced, you’ll find broad availability and competitive pricing for square tubing in various tamanho e espessura da parede ranges.

What is stainless steel square tube
304 vs aço carbono: carbon grades can be strong and lower-cost, but they rust without paint or galvanizing. 304 stainless steel square tube resists rust, needs less manutenção, and delivers a higher-end appearance for arquitetura and public spaces.
304 vs alumínio: aluminum is lighter, but softer. Where durabilidade and dent resistance matter, 304 wins. In many builds—especially architectural ou industrial settings needing a crisp, ornamentais look—304’s finish and rigidity provide better long-term estética and lifecycle value.
Below is a practical snapshot. Always confirm the dimensão e espessura da parede you need per local codes or engineer guidance.
| Outside Size (mm) | Wall Thickness (mm) | Approx. kg/m | Typical Finish Options |
| 20 × 20 | 1.0 – 2.0 | 0.6 – 1.2 | Acabamento da fresa, brushed, mirror |
| 25 × 25 | 1.2 – 3.0 | 0.9 – 2.2 | Acabamento da fresa, brushed, mirror |
| 40 × 40 | 1.5 – 4.0 | 1.7 – 4.4 | Acabamento da fresa, brushed, mirror |
| 50 × 50 | 2.0 – 6.0 | 3.1 – 9.1 | Acabamento da fresa, brushed, mirror |
| 80 × 80 | 3.0 – 6.0 | 7.4 – 14.6 | Acabamento da fresa, brushed, mirror |
Tip: When you specify tamanho, also include cut lengths and tolerance. That reduces waste in the shop.
Tipo 304 provides a balanced property set for general use: solid tensile strength, good strength-to-weight, and dependable toughness down to modest sub-zero temps. It’s resistant to many everyday chemicals and delivers resistência à corrosão in typical city atmospheres and fresh water.
In splash zones or de-icing salts, consider upgrading to 316. That’s especially helpful for marinha docks or ambientes de água salgada. In harsher química exposure (strong acid or chloride), consult your engineer for a different grau or a protective design detail.
Many builders choose 304 stainless steel square sections for light framework, bracing, and suportes estruturais that stay exposed. The neat geometry seats well against plate and gussets, and the straight sides make bolted connections easy to lay out.
Para aplicações estruturais needing higher section modulus, jump up a tamanho ou espessura da parede, or compare to retangular sections for directional stiffness. Use the rodada e quadrado family together: tubo inoxidável (round) for bridges between frames, and square for frames or a column aesthetic.

Aplicações estruturais
Square sections give strong apelo visual. They read modern and sharp. You see them in corrimão systems, kiosks, brand fixtures, and architectural signage. The clean faces make it simple to align panels and lighting.
Because surfaces are frequently touched, specify a consistent acabamento. Brushed looks hide fingerprints; mirror shows premium aesthetic impact. Either way, stainless steel square components remain durável, reduce repaint cycles, and protect total cost of ownership.
Em industrial applications, 304 is a proven choice for light racks, platforms, and guards. For processamento de alimentos, 304’s smooth surfaces are hygienic and easy to sanitize.
Near coastlines or splash zones on marine equipment, consider 316 for tougher chloride exposure. For mild química processes, 304 often works, but always check the media and temperature. If the ambiente is strongly acidic, seek materials or coatings specifically rated for that duty.
A mill finish is the starting point—uniform, cost-effective, and ready for fabrication. A polimento (brushed or mirror) elevates the look for premium interiors or storefronts.
Routine cleaning is simple: wash with mild detergent and water. That’s the manutenção most jobs need. Avoid harsh cleaners that might attack the passive layer, and rinse thoroughly after cleaning.
You can cut 304 square sections with laser ou plasma for burr-free edges and tight tolerance. Sawing is fine for general cuts; dress the edges for safety.
Fabricators like 304 because it’s consistent and friendly to solda. If your design needs sealed seams, ask for aço inoxidável soldado tubing per common standards (e.g., A554 for mechanical). It takes coatings and decals well if brand marks are needed, and it nests neatly with plates for clean, strong joints.

cutting 304 square sections with laser
When you place an order, call out:
Good specs reduce surprises, control cost, and improve schedule. If you’re designing multi-shape kits, request a quote for mixed bundles (square/rectangular/round) to optimize freight.
Disponibilidade para 304 stainless steel square tubing is strong worldwide. Stock lists often include 20–80 mm outside sizes with common walls. Custom runs are possible for larger sections or unusual walls.
On shipping, bundle by project phase to reduce receiving steps. Ask about lead times for non-stock items and coordinate with your installer. Choose a fornecedor with mill test reports, dimensional checks, and stable QC for repeat orders—especially when a single finish must match across sites.
Is 304 stainless square tube magnetic?
304 is generally non-magnetic in the annealed state. Cold work can induce slight magnetism. If low magnetic permeability is critical, specify it up front and test samples.
What finish should I choose for public railing?
Brushed finishes hide fingerprints and minor scuffs. Mirror gives a premium look but shows handling more readily. Match the acabamento to traffic level and cleaning plan.
Can I use 304 near the ocean?
Yes, but for piers and direct splash from the sea, 316 usually performs better in ambientes de água salgada. For inland marinha climates with occasional salt exposure, 304 may suffice with proper design and cleaning.
How does square compare to round for structures?
Square makes flat-face connections easy and looks modern. Round is efficient for torsion and bending. Many projects use both: square for frames and round for ties and rails.
Does 304 handle mild acids or cleaners?
In many cases yes, but always test the exact química and concentration. Persistent acid splash or high-temperature chlorides demand special care or upgraded materials.
Can I get matching rectangular and square in one delivery?
Absolutely. It’s common to order both for optimized performance. Many service centers stock coordinated retangular and square families to keep your look consistent.
On a coastal retail job, we paired 50×50×2.5 mm square with 40×20×2.0 mm retangular stringers. Using brushed finish kept fingerprints under control. Factory miter cuts with laser saved 12 hours on-site and improved fit at every corner. The owner praised the clean lines and long-term versatilidade of the system.
304 Stainless (Square)
Carbon Steel (Square)
Aluminum (Square)
From our production floor and customer projects, we validate incoming coils, check weld seams, and hold samples to mechanical specs common to A554 (mechanical tubing). For further reading, many engineers also consult typical 304 data sheets and code references; your project engineer’s spec is the final source of truth for acceptance.
If you’re planning a build and want consistent finish across industrial e architectural areas, we can align cuts, bundles, and staging by zone. Tell us your tamanho, quantity, and timeline, and we’ll line up stock and processing. We’re here to help—from sample to install.
What’s the difference between 304 stainless steel square tube and 304 stainless steel square tubing?
None—both phrases describe the same product. Some catalogs prefer “Tubo quadrado de aço inoxidável” while others shorten it to “square tube.”
Can I TIG or MIG weld 304 square sections on site?
Yes. Use proper filler and shield. Prep the joint, back-purge when required, and clean heat tint after the solda passes.
Do I need passivation after cutting or welding?
It helps restore the chromium oxide layer. Many shops clean and passivate after fabrication for best long-term performance.
Is 304 safe for food contact?
Yes for many uses; it’s widely used in processamento de alimentos equipment. Always follow local regulations and hygiene practices.