Which Bar is Right for Your Project? HYSD, CTD, QST, and Mild Steel Compared
If you’re looking to pick up some new bars to complete your next project, but you aren’t sure what the different bars are or which one will work best, then you’ve come to the right place! We have compiled this comprehensive guide to help you determine which of these bars will be right for your project and why. Check out our comparison about what are the differences between mild steel, HYSD, CTD, and QST bars?, where we break down all the details on HYSD, CTD, QST, and mild steel bars so that you can make an informed choice about what will work best for your particular project and circumstances.
Not only are mild steel bars cheap, but they’re easy to find at the local hardware store. However, mild steel isn’t ideal for all applications, and sometimes other bars work better, depending on the project you’re working on. Let’s take a look at four types of steel bars and how they can be used in your next project!

Why You Should Know About The Different Types of Bars
If you work in construction or trade, there’s a good chance you’ve come across several different types of bars: HYSD (high yield structural deformed), CTD (cold drawn deformed), QST (quenched and tempered), mild steel. And while that may seem very complex to some of us who aren’t familiar with it, understanding these differences can make a big difference in choosing which bar to use for your project.
Which Type of Bar Do I Need For My Project?
Structural steel, high-yield steel (HYSD), copper tube-deformed bar (CTD), or quenched and tempered bar (QST)? These are all common structural materials that contractors can use on various projects. Here’s a comparison of these structural steel bars to help you decide which type will work best for your project. 3 Ways to Choose a Type of Structural Steel: Mild steel bar: This is an economical option, but it isn’t designed for load-bearing applications. Mild steel should be used when its strength properties aren’t required—for example, as temporary bracing while construction continues around it. It’s also not suitable for applications in which welded connections might weaken it; in such cases, choose one of the other three options listed here.
Mild Steel – The Most Common Choice
When most people think of reinforcing bars, they picture mild steel. Due to its corrosion resistance and durability, mild steel has been used as a building material since antiquity. While it isn’t as easy to work with as other options, it’s incredibly flexible—and can be installed in any direction. For most small-scale building projects (like a garage or shed), you’ll want to choose mild steel reinforcement bars. They’re available in both regular strength (RS) and high-yield strength (HS) varieties. The HS variety typically has a yield strength of 35 MPa or more; RS bars typically have yield strength of 20 MPa or less—although some manufacturers produce super RS bars that are even stronger than traditional RS bars!
HYSD – High Yield Strength Deformed Bars
these bars are used in reinforced concrete applications where compression strength is needed. This bar has limited use in general construction applications due to more stringent requirements when compared to either CTD or QST products. In fact, in most cases, no explicit warranty coverage for HYSD due to its specialized nature. Additionally, less precise product tolerances are commonly permitted; ensuring that a degree of corrosion resistance can be achieved while reducing overall cost. SYD bars will often carry more weight than either a mild steel product or even some brands of carbon steel.

Quenched & Tempered (QST) – Maximum Durability
Heat-treating a steel bar between 1350°F – 1550°F has two distinct effects. First, it alters its crystal structure through solid-state diffusion (SSD) – changing how small grains of carbide are distributed throughout. This creates a very uniform grain structure that is stronger and more resistant to cracking than its untreated counterpart. Second, quenching tempers steel as it undergoes rapid cooling which relieves internal stresses in both strength-critical areas like welds & bends as well as around corners & edges where strain can build up over time. The end result is a bar that stands up to heavy loads without fatiguing or losing shape over time from heat build-up in specific areas of usage.
Low Alloy Structural/Deformed (CTD) – Harder Than Hot Rolled Bars But Some Special Treatment Required
If you’re looking to save weight on your project without sacrificing strength, CTD bars may be a great option. These bars can also be used to manufacture smaller parts that would otherwise be harder to produce with higher grade bars. However, you should note that these are more expensive than lower grades of steel and require special treatment before use. In particular, they need to be preheated in an oven at 325°F (163°C) for at least 10 minutes prior to use—and at no point during a cold working process should they be allowed to cool below room temperature (77°F/25°C). It’s a hassle but worth it if you want the specialized product or cost savings.