ASTM A554 Stainless Steel Box Section

Premium stainless steel square tubes from YES Stainless International.

YES Stainless International manufactures ASTM A554 square stainless steel tube (also called stainless steel box section) for architectural and mechanical applications that demand clean faces, controlled corners, and true squareness. Square tubes are formed from a round tube by cold shaping and sizing. Corners are the stress focus in this process, so we control the weld seam and forming steps to reduce the chance of cracks or splitting during forming and downstream fabrication. Common grades include 430, 304/304L, and 316/316L with cosmetic finishes from No.4 and Hairline to 180G, 240G, 320G, 400G, and 600G mirror. We keep width (across flats), wall thickness, right-angle corners, twist, and corner radius within strict limits for uniform assemblies on site.

What is ASTM A554?

ASTM A554 specifies welded stainless steel tubes for mechanical and decorative service. For non-round shapes, it defines requirements for corner radius, squareness, twist, and dimensional tolerances that support visible installations. It is not a pressure-piping standard; instead, it focuses on appearance, geometry, and formability for handrails, façades, furniture, kiosks, and light structural elements.

Product Overview of ASTM Att4 Stainless Box Section

International Standard	Dimension	Stainless Steel Grade	Surface Finishes
ASTM A554 JIS G3446	OD: 12.7x12.7~150x150mm WT: 0.7~6.5mm Standard Length: 6M	MT304, MT304L, MT316L, MT430 Grade 201, 202 as per mill's STD SUS304	Mill Finish, 180G, 240G, 320G,400G, 600G (Mirror)

Key Features of ASTM A554 Stainless Steel Box section

Flat, consistent faces: Controlled face bow and gloss help panels, cladding, and frames look even in direct light.
Weld engineered for forming: Weld seam conditioning and forming windows are set to lower the risk of seam splitting during further fabrication.
Cosmetic finish consistency: Even grain and gloss across all tubes, from No.4 and Hairline to high-reflectivity mirror.

Product Specification of ASTM A554 Stainless Steel box section

Outside Diameter	Thickness (mm)
mm	0.4	0.5	0.6	0.7	0.8	0.9	1.0	1.2	1.5	2.0
12.7x12.7	●	●	●	●	●	●	●
15x15	●	●	●	●	●	●	●	●
16x16	●	●	●	●	●	●	●	●
19x19	●	●	●	●	●	●	●	●
20x20	●	●	●	●	●	●	●	●	●	●
22x22	●	●	●	●	●	●	●	●	●	●
25x25	●	●	●	●	●	●	●	●	●	●
30x30	●	●	●	●	●	●	●	●	●	●
31.8x31.8	●	●	●	●	●	●	●	●	●	●
38x38	●	●	●	●	●	●	●	●	●	●
40x40	●	●	●	●	●	●	●	●	●	●
50x50	●	●	●	●	●	●	●	●	●	●
60x60	●	●	●	●	●	●	●	●	●	●
80x80	●	●	●	●	●	●	●	●	●	●

FAQs

1. How can I verify the surface finish before ordering?

We can send a finished sample set for ASTM A554 square stainless steel tube covering 180G, 240G, 320G, 400G, and 600G mirror finishes. Samples show the surface finish, weld seam, and corner radius under real light. Once confirmed, we lock that as the control finish for production to ensure products meet your expectations.

2. How do you reduce the risk of corner splitting?

We condition the weld bead, control the reduction ratio, and manage seam orientation during forming. These controls reduce strain concentration at the corners and help prevent weld-seam splitting.

3. Can you supply a mirror finish on square sections?

Yes. 400G and 600G mirrors are available with protective film to preserve the surface through fabrication and installation.

4. Are there larger sizes available?

Yes. Please share your sizes with us, and our technical salesperson will discuss with you about the feasibility.

5. What is the minimum order quantity (MOQ)?

Our stainless steel pipes and tubes are typically supplied in 6 m lengths. To reduce damage risk and optimize freight, we recommend a full-container load of about 20 MT. However, we also accept smaller orders. Share your size mix and destination, and we will propose safe packing and the most economical shipping plan.