304
General purpose
Widely used for brackets, frames, equipment components, architectural trim and general stainless fabrication.
Product form hub · Square bar
Stainless Steel Square Bar
Specify stainless steel square bar by grade, side dimension, production route, tolerance, finish, straightness and length. 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 drawn or forged
Solid square bar · product visual
Common grades304 / 304L / 316 / 316L
Common market size6 × 6 to 100 × 100+ mm
Common lengths3 / 4 / 6 m and cut length
Build the specification
01Choose grade
02Set square size
03Choose bar route
04Define tolerance / finish
05Confirm length / corners
06Send RFQ
Product overview
What to define before buying stainless steel square bar
Square bar is specified primarily by the side dimension, but a clear order should also define grade, production route, tolerance, corner condition, finish, straightness and length. These details matter when the bar will be welded, machined or used as a visible structural component.
Material304 / 304L
Common for general fabrication, machine parts, supports and architectural stainless components.
Material316 / 316L
Frequently selected where chloride exposure, washdown or more demanding corrosion resistance is expected.
GeometrySide × side
Specify the solid square section directly, for example 25 × 25 mm or simply 25 mm square.
Bar routeHot rolled, cold drawn or forged
The production route affects corners, straightness, surface appearance, dimensional tolerance and machining allowance.
M03 · Grade selection
Choose the grade from corrosion, fabrication and service needs
Square bar is commonly sawn, drilled, turned, milled or welded after purchase. Grade selection should consider corrosion exposure, fabrication, machining and the final service environment rather than only 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 square bar size reference
The table below uses common commercial square-bar sizes for early design and RFQ preparation. Exact availability depends on grade, production route, finish, tolerance and order quantity.
| Square size | Common grade routes | Typical production route | Common length reference | Buying note |
|---|---|---|---|---|
| 6 × 6 mm | 304 / 304L | Cold drawn / cold finished | 3–6 m | Small hardware, pins and precision fabrication |
| 8 × 8 mm | 304 / 304L / 316L | Cold drawn / cold finished | 3–6 m | Common small-section square bar |
| 10 × 10 mm | 304 / 304L / 316 / 316L | Cold drawn / hot finished | 3–6 m | General fabrication and machined components |
| 12 × 12 mm | 304 / 316L | Cold drawn / hot finished | 3–6 m | Useful for brackets, supports and fittings |
| 16 × 16 mm | 304 / 304L / 316L | Cold drawn / hot finished | 3–6 m | Common medium-small section |
| 20 × 20 mm | 304 / 304L / 316 / 316L | Cold drawn / hot rolled | 3–6 m | General fabrication and machining |
| 25 × 25 mm | 304 / 316L | Cold drawn / hot rolled | 3–6 m | Frequently specified commercial size |
| 30–32 mm square | 304 / 316 / 316L | Cold drawn / hot rolled | 3–6 m | Confirm corner and tolerance route |
| 40 × 40 mm | 304 / 304L / 316L | Hot rolled / cold finished | 3–6 m | Structural and machined components |
| 50 × 50 mm | 304 / 316L | Hot rolled / cold drawn by supplier | 3–6 m | Production route becomes more important |
| 60–80 mm square | 304 / 316 / 316L | Hot rolled / forged / selected cold-finished routes | 3–6 m | Confirm tolerance, straightness and machining allowance |
| 90–100+ mm square | 304 / 316L / other grades by order | Hot rolled / forged | Supplier-dependent | Large sections are usually project-specific |
Market reference: stainless square bar is commonly sold in sizes from small cold-drawn sections around 6–10 mm square through hot-finished or forged sections above 50–100 mm square. For purchasing, state side dimension, grade, length, production route and any critical tolerance or straightness requirement.
M05 · Dimensions and finish
Define the square size, route and corner condition
Square bars with the same nominal side dimension can differ in tolerance, corner radius, straightness and surface condition depending on whether they are hot rolled, cold drawn or forged.
Dimensions
- Side × side dimension
- Standard length or cut length
- Across-flat tolerance if critical
- Straightness requirement for machining
- Corner radius / squareness if assembly-critical
Production route
- Cold drawn / cold finished square bar
- Hot rolled square bar
- Hot forged large-section bar
- Ground or machined precision stock
- Cut-to-length or sawn blanks
Surface & processing
- Hot-finished / pickled surface
- Bright cold-finished surface
- Ground / machined faces where specified
- Saw cut / drilled / milled processing
- Protected packing for finished surfaces
M06 · Selection guide
Match the square-bar route to the job
General fabrication304 / 304L is a common starting point for frames, supports and welded components in moderate environments.
Precision machiningCold-drawn or ground stock is often preferred when dimensional consistency, straighter bars and lower machining allowance matter.
Coastal / chloride exposure316 / 316L is commonly considered where chloride exposure or washdown is more demanding than a general indoor environment.
Large section / heavy partHot-rolled or forged square bar may be more practical for larger sizes; specify machining allowance and final dimensional requirements.
Worked example
Example of a clear square bar specification
A usable request defines the solid square section, bar route and downstream processing requirements instead of ordering only by grade and nominal size.
Example only
This is a normal buying example, not a live-stock claim. Final requirements should follow the project drawing, service environment and machining plan.
ProductStainless steel square bar
Standard routeASTM A276/A276M with ASTM A484/A484M general requirements
Grade304L
Size25 × 25 mm
Production routeCold drawn / cold finished
Length6 m or cut-to-length as required
Order requirementState quantity, destination, tolerance, cutting and document requirements in the RFQ
M08 · Applications
Where stainless steel square bar is commonly used
Machined components
Blocks, spacers, guides, shafts with milled features, valve parts and custom precision components.
Frames & supports
Welded frames, machine bases, bracing and fabricated stainless structural components.
Architectural work
Posts, rails, decorative elements and visible hardware where straightness and surface appearance matter.
Food & process equipment
Equipment frames, brackets and fabricated components requiring corrosion resistance and cleanability.
Marine / outdoor hardware
316 / 316L square bar is often considered for more demanding chloride and outdoor exposure.
General engineering
Jigs, fixtures, keys, supports and custom parts produced from solid square stainless stock.
Important limitation: nominal square size alone does not define the finished part. Hot-rolled, cold-drawn and forged routes can differ in corner radius, dimensional tolerance, straightness, surface scale and machining allowance. If the bar will be precision-machined or used in a close-fitting assembly, state the required route and tolerance on the RFQ.
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 size tolerance, corner condition, straightness, surface finish, heat treatment, machining or inspection, state the requirement directly on the RFQ or drawing.
M11 · FAQ
Stainless steel square bar FAQ
How is stainless steel square bar sized?
Specify the side dimension and length. For example, 25 × 25 mm square bar in 6 m lengths. Add grade, production route, tolerance, finish and corner requirements where they matter.
What grades are most common?
304 / 304L and 316 / 316L are among the most common stainless square-bar grades. Grade selection should follow corrosion exposure, welding, machining and the final service environment.
What is the difference between hot-rolled and cold-drawn square bar?
Hot-rolled bar is generally used where heavier sections and less demanding surface or dimensional requirements are acceptable. Cold-drawn bar is typically smoother and dimensionally tighter, making it useful for machining and closer-fitting fabrication.
Can stainless square bar be machined or polished?
Yes. Square bar is commonly sawn, drilled, milled, turned after profiling, ground or polished. Specify the required starting tolerance and surface condition if machining allowance or appearance is important.
Which standards are commonly referenced for stainless square bar?
ASTM A276/A276M is a common stainless bar-and-shape specification, with ASTM A484/A484M providing general requirements. The project drawing or purchase specification should define the final requirement.
Product details
What buyers usually verify visually
Review representative square-bar inspection, fabrication and packing evidence before finalizing the purchase specification.
Square geometry & cornersSide dimension, squareness, corner radius and straightness
Surface & bar routeHot-finished, bright cold-drawn, ground or polished appearance
Cut length & packingSawn ends, bundled bars and protection for finished surfaces
Square bar resources
Continue from specification to purchase
Material hub
Stainless Steel
Review the parent material hub and related stainless steel product forms.
Open stainless steel hub → Technical Technical ResourcesUse standards, comparisons and engineering references to clarify the purchase specification.
Open technical resources → Sourcing Request a QuoteMove from a reviewed specification to a purchasing conversation.
Open RFQ page →M13 · Technical reference
Reference basis for this square bar guide
The page uses ASTM A276/A276M bar-and-shape requirements, ASTM A484/A484M general requirements and common commercial stainless square-bar size patterns. Exact size, tolerance, finish, straightness and certification should be confirmed for the actual order.
M14 · RFQ
Request a technical quote
For a faster review, include the grade, square size, production route, tolerance or finish, length, quantity, destination and any cutting, machining or document requirement.
- Grade / material designation
- Square size / side dimension
- Production route, corner condition and finish
- Length / cutting / machining requirement
- Quantity, destination and required documents