Use a magnet, a test reagent and visual inspection to tell genuine 304 stainless steel from poor-quality material, so you do not buy the wrong thing when making a gate or railing.
Many homeowners who had a stainless steel gate or railing made see stains and rust after a few months, only to find that the workshop used a lower grade than agreed. Here are some simple ways to check.
1. Use a magnet
Pure 304 stainless steel is almost non-magnetic. 201 stainless steel is slightly magnetic. However, this is only a preliminary check, because 304 can become slightly magnetic at bends after bending or stamping. Do not rely on this method alone.
2. Use a stainless steel test reagent
This is the more reliable method. A dedicated reagent is dropped on a freshly ground surface and changes color according to the nickel and chromium content. 201, 304 and 316 each give a different color according to the manufacturer's instructions. Reagents are sold at industrial supply stores for a few tens of thousands of dong.
3. Look at the surface
304 stainless steel has a bright, even, silvery surface. 201 stainless steel tends to look yellower or grayer and is prone to tiny brown spots after some time outdoors.
4. Check the material certificates
Ask the workshop to show the invoice or certificates (CO, CQ) for the batch of stainless steel. A reputable workshop does not mind letting customers see the labels on the tubes and sheets.
5. Ask about weight and thickness
Tubes thinner than agreed are another common trick. Use calipers to measure the wall thickness. A tube sold as 1.2 mm but only 0.9 mm thick is clearly cheaper.
6. Put it in writing in the contract
The quote should state: the stainless steel grade (201, 304 or 316), tube dimensions, thickness, finish (polished or brushed) and warranty period, signed by both parties.
Advice
A price far below the market usually means inferior material. Choose a workshop with a clear address and real projects you can visit. Phu Phong always states the material clearly and lets customers test samples on site. Contact Inox Phu Phong on hotline 0913 706 536 (Mr. Phong) for a free survey and quote in Long Xuyen and the neighboring districts of An Giang.
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