304
General purpose
Widely used for brackets, frames, equipment components, architectural trim and general stainless fabrication.
Product form hub · Flat bar
Stainless Steel Flat Bar
Specify stainless steel flat bar by grade, width, thickness, production route, finish, length and edge condition. Use the size references and selection notes below to turn a general request into a clear purchasing specification.
304 / 304L / 316 / 316L
ASTM A276 / A484 route
Hot rolled, cold finished or polished
Solid rectangular bar · product visual
Common grades304 / 304L / 316 / 316L
Common market width15 to 300 mm
Common market thickness2 to 50+ mm by route
Build the specification
01Choose grade
02Set width
03Set thickness
04Choose bar route / finish
05Confirm length / edges
06Send RFQ
Product overview
What to define before buying stainless steel flat bar
Flat bar looks simple, but width and thickness alone are not enough. The buyer should also define grade, bar-production route, edge condition, finish, length and any machining or polishing requirement.
Material304 / 304L
Common for general fabrication, equipment, brackets and architectural work in moderate environments.
Material316 / 316L
Frequently chosen where chloride exposure or more demanding corrosion resistance is required.
GeometryWidth × thickness
Specify the solid rectangular section directly, for example 50 × 6 mm.
Bar routeRolled, drawn, sheared or ground
The manufacturing route affects edge shape, surface appearance, tolerance and cost.
M03 · Grade selection
Choose the grade from corrosion, fabrication and service needs
Flat bar is commonly welded, drilled, machined or polished after purchase. Grade selection should consider the real environment and the downstream fabrication route, not just the nominal alloy name.
304L
Weld-friendly low carbon
Common when extensive welding is expected and a low-carbon 304 route is preferred.
316
Higher corrosion resistance
Often considered for coastal, marine-adjacent, chemical and washdown environments.
316L
Corrosion + welding route
Frequently specified when both welding and improved chloride resistance are important.
M04 · Technical data
Common stainless steel flat bar size reference
These dimensions reflect common commercial flat-bar patterns seen across stainless suppliers. They are useful for early design and RFQ preparation, but exact availability depends on grade, bar route, finish and supplier stock.
| Width | Common thickness reference | Typical grade routes | Typical production / finish route | Buying note |
|---|---|---|---|---|
| 15–20 mm | 2 / 3 / 4 / 5 / 6 mm | 304 / 304L | Cold finished / sheared / polished | Light brackets, trim and hardware |
| 25 mm | 3 / 4 / 5 / 6 / 8 mm | 304 / 304L / 316L | Rolled / cold finished / polished | Common fabrication width |
| 30–32 mm | 3 / 4 / 5 / 6 / 8 / 10 / 12 mm | 304 / 304L / 316 / 316L | Hot rolled / cold finished | Useful general-purpose size family |
| 40 mm | 3 / 4 / 5 / 6 / 8 / 10 / 12 / 13 mm | 304 / 316L | Rolled / edge conditioned / polished | Frames, supports and equipment parts |
| 50 mm | 3 / 4 / 5 / 6 / 8 / 10 / 12 / 13 mm | 304 / 304L / 316L | Rolled / sheared & edged / polished | One of the most common broad flat sizes |
| 60–65 mm | 4 / 5 / 6 / 8 / 10 / 12 / 13 mm | 304 / 316 / 316L | Hot rolled / cold finished | Heavier brackets and fabricated supports |
| 70–80 mm | 4 / 5 / 6 / 8 / 10 / 12 / 13 mm | 304 / 316L | Rolled / machined / polished | Confirm edge condition when visible |
| 90–100 mm | 5 / 6 / 8 / 10 / 12 / 13 / 15 / 20 mm | 304 / 316L | Hot rolled / cut / machined | Confirm flatness and tolerance if machining follows |
| 120–150 mm | 6–25 mm commonly encountered | 304 / 316L | Rolled or cut flat bar route | Production route becomes more important |
| 200–300 mm | 8–50+ mm supplier-dependent | 304 / 316L / other grades by order | Hot rolled / cut / machined | Confirm whether the offer is true flat bar or plate-derived flat |
Market reference: commercial catalogs commonly show stainless flat bar around 15–300 mm wide, with thin-bar ranges near 2–13 mm and thicker hot-finished / cut routes extending much further. For procurement, always state width × thickness, grade, length and required bar route or edge condition.
M05 · Dimensions and finish
Define how the flat bar is produced and finished
Two pieces with the same width and thickness can behave very differently in machining, welding and visible fabrication if their edges, finish or production route are different.
Dimensions
- Width × thickness
- Standard length or cut length
- Width / thickness tolerance if critical
- Flatness and straightness if machining follows
- Corner / edge geometry if assembly-critical
Bar / edge route
- Hot rolled flat bar
- Cold finished / cold drawn bar
- Sheared and edge-conditioned flat
- True flat bar / tighter-edge route
- Precision ground or machined bar
Surface & processing
- Mill / hot-finished surface
- Pickled or bright-finished route
- Brushed / No.4 polished surface
- Cut to length / drilled / machined
- Protective packing for cosmetic surfaces
M06 · Selection guide
Match the flat-bar route to the job
General welded fabrication304L is a common starting point when substantial welding is expected and the environment is not highly aggressive.
Visible architectural workSpecify polished faces, edge appearance and scratch protection rather than ordering only by grade and size.
Coastal / chloride exposure316 / 316L is commonly considered before 304, but the real environment and maintenance conditions still control selection.
Machined componentDefine the required dimensional tolerance, flatness, edge condition and whether cold-finished, ground or machined stock is preferred.
Worked example
Example of a clear flat bar specification
A usable request tells the supplier what rectangular section is needed and how the bar should arrive for the next fabrication step.
Example only
This is a normal buying example, not a live-stock claim. Use the project drawing and real service conditions to finalize the order.
ProductStainless steel flat bar
Standard routeASTM A276/A276M with ASTM A484/A484M general requirements
Grade316L
Size50 × 6 mm
Length6 m or cut-to-length as required
Finish / edgesMill finish, edges suitable for fabrication
Order requirementState quantity, destination, cutting and document requirements in the RFQ
M08 · Applications
Where stainless steel flat bar is commonly used
Brackets & supports
Mounting plates, straps, reinforcement pieces and fabricated support components.
Frames & fabrication
Welded frames, skids, guards and industrial stainless assemblies.
Architectural details
Trim, decorative rails, edging and visible components that may require brushed or polished faces.
Machine components
Machined blocks, spacers, guides and parts produced from rectangular bar stock.
Food & process equipment
Framework and fabricated equipment components where corrosion resistance and cleanability matter.
Marine / outdoor hardware
316 / 316L flat bar is commonly considered for more demanding chloride exposure.
Important limitation: “flat bar” can mean a true rolled / cold-finished bar or a narrow strip cut from plate or sheet. These routes can differ in edge condition, corners, flatness, tolerance and mechanical-property requirements. If the distinction matters, specify the product route directly rather than ordering only by width × thickness.
M10 · Standards
Standards and purchasing references
Use the latest project-approved revision and state it on the purchase specification. Standard numbers below are shown as technical references only.
Common stainless bar-and-shape specification covering hot-finished or cold-finished bars in widely used stainless grades.
General requirements for wrought stainless bars, billets, shapes and forgings, including dimensional and ordering controls used with product specifications.
For critical tolerance, edge condition, surface finish, heat treatment, machining or inspection, state the requirement directly on the RFQ or drawing.
M11 · FAQ
Stainless steel flat bar FAQ
How is stainless steel flat bar sized?
Specify width × thickness, then add length. For example, 50 × 6 mm flat bar in 6 m lengths. Grade, bar route, finish and edge condition should be added when they matter.
What grades are most common?
304 / 304L and 316 / 316L are among the most common stainless flat-bar grades. The correct choice depends on corrosion exposure, welding and the final service environment.
What is the difference between true flat bar and sheared flat bar?
A true rolled or cold-finished flat bar is produced as bar stock. Sheared flat can be cut from wider sheet or plate. Edge shape, corner condition, flatness and dimensional tolerance may differ, so define the route when it affects the job.
Can stainless flat bar be polished?
Yes. Brushed / No.4 and other polished finishes are common market options. If the bar remains visible, specify which faces and edges need a cosmetic finish and whether protective film or special packing is required.
Which standard is commonly used for stainless flat bar?
ASTM A276/A276M is a common stainless bar-and-shape route, with ASTM A484/A484M providing general requirements. The actual project specification should control the purchase.
Product details
What buyers usually verify visually
These three areas are ready for your own flat bar photos. Replace only the background images later; the page structure and copy can stay unchanged.
Bar geometry & edgesWidth, thickness, edge condition and rectangular section
Surface finishMill, bright, brushed, polished or ground appearance
Cutting & packingLength, bundled bars and protection for finished surfaces
Flat bar resources
Continue from specification to purchase
M13 · Technical reference
Reference basis for this flat bar guide
The page uses the current ASTM A276/A276M bar scope, ASTM A484/A484M general requirements and common commercial stainless flat-bar dimension patterns. Exact stock, tolerance, finish and certification should be confirmed for the actual order.
M14 · RFQ
Request a technical quote
For a faster review, include the grade, width, thickness, bar route or finish, length, quantity, destination and any cutting, machining or document requirement.
- Grade / material designation
- Width × thickness
- Bar route, edge condition and finish
- Length / cutting / machining requirement
- Quantity, destination and required documents