TIS is a mark developed by the Thai Industrial Standard Institute to certify the quality of manufactured industrial products. The TIS certification mark includes general standard certification marks, mandatory certification marks, safety certification marks, and environment certification marks. 

The products certified by TIS are quality products that meet the required standard. The steel industry has a regular TIS inspection. It is illegal to supply steel without TIS marks.

• Thai Industrial Standard Round Bar

– Round bar: TIS 20-2559 Grade SR24, Size RB6 and RB9, length 10m/ bar, approximately 1.50-2.00 tons/coil

– Deformed bar: TIS 24-2559 Grade SD40 and SD50, Size DB12, DB16, DB20, DB25, DB28, DB32 and DB40, length 10–12 m.

• Identifying the TIS certified steel bar

1. Visual inspection: The diameter of a cross-section is the same the throughout the entire length of the bar.  The bar is smooth, with no damages, air voids, or waves.

2. Label or nameplate checking: The label or nameplate provides essential and complete information, such as the company name, product type, grade quality, size, length, quantity per bundle, furnace number, production date/time, and TIS number. The nameplate, however, is only available in mass ordering. In the case of small orders or label loss, observe the TIS marks and information that should appear on the steel bar.

3. Weighing: Cut the steel chosen for inspection into 1 m and weigh it. If the weight is in accordance with the TIS, the steel is good and of standard properties.