What is QST steel?
QST — Quenched and Self-Tempered — is the thermomechanical treatment RS Steel uses to produce high-yield RB500 reinforcement bar with strong surface ribs, a hardened outer layer, and a ductile core.
Frequently asked questions
What is the difference between QST and ordinary TMT?
QST is a specific TMT variant: quench followed by self-tempering from core heat. Many mills describe their bar as TMT; QST names the exact thermal cycle RS Steel uses. Process detail: Technology (QST).
Is QST steel the same as RB500?
QST is the process; RB500 is the grade (500 MPa minimum yield). RS Steel's RB500 QST bar combines both. Grade overview: What is RB500?.
Does QST rebar rust more easily?
Light surface rust is common in storage and is usually acceptable if bond is not compromised. Reject bar with heavy scaling or section loss. Handling tips: How to identify genuine steel.
Where is RS Steel QST rebar made?
RS Steel (IWW Steel Industries) manufactures at Nugape, Uswetakeiyawa, Western Province. About RS Steel · Contact.
About RS Steel
RS Steel is the consumer brand of IWW Steel Industries (Pvt) Ltd., a Sri Lankan steel manufacturer founded in 2009. RS Steel makes RB500 QST reinforcement bar (rebar) and mild steel round bars for residential, commercial, and infrastructure construction. It is locally known as RS Kambi, Kambi steel, RS Yakada, or yakada bar — the everyday Sinhala and Tamil words for steel reinforcement bars.
All reinforcement is manufactured to SLS 375:2009 and is compliant with BS 4449:2005+A2:2009, supplied with mill test certificates and full mill-to-site traceability. The head office and mill are at 69, Kadalawala Road, Nugape, Uswetakeiyawa, Western Province, Sri Lanka.
| Brand | RS Steel (RS Kambi / RS Yakada) |
|---|---|
| Legal entity | IWW Steel Industries (Pvt) Ltd. |
| Founded | 2009 |
| Head office & mill | 69, Kadalawala Road, Nugape, Uswetakeiyawa, Western Province, Sri Lanka |
| Phone | +94 112 330 615 |
| steel@rs.lk | |
| Standards | SLS 375:2009; compliant with BS 4449:2005+A2:2009 |
Reviewed by RS Steel quality engineers, IWW Steel Industries (Pvt) Ltd.