quenchedQuenched and tempered plate, a steel that is stronger and harder than ordinary carbon steel. The product is used for the manufacture and repair of machinery and structures where greater abrasion resistance or higher yield strength are required.

It is not uncommon in our industry to find the same type of steel plate given different names by different engineers.
Plates of this type are variously described as:

  • High Strength Quenched and Tempered Steel Plate
  • High Yield Quenched and Tempered Steel Plate
  • High Strength Structural Steel Plate,
  • High Yield Structural Steel Plate
  • High Strength Low Alloy Steel Plate
  • HSLA

This type of steel plate is used in the manufacture of cranes, forklifts, bridges, offshore fabrications, mining and quarrying equipment, mooring equipment, and vehicle chassis to name but a few applications.

Machining :

The RQT range can be machined and drilled using high-speed steel or cemented carbide tools.  The approximate hardness of the RQT range can be obtained from the value of the ultimate tensile strength and falls within the range 240-280 BHN.

Welding :

Care should be taken to avoidhydrogen cracking and there are many factors to take into consideration before welding.  Full technical guidance for welding is available from the sales/technical team at Triton alloys Co.

Technical Specifications : 

Flame Cutting :

RQT steels can be cut satisfactorily using conventional oxy-fuel gas practices, in many cases without the need for preheat, as long as cutting procedures take into account plate thicknesses and carbon equivalent values. Water jet, where no heat is generated, or plasma cutting can also be used. Care should be taken when cutting under water as the quenching effect could result in a high hardness edge forming.  With all thermal cutting processes care should be taken that cut edges are free from sharp notches.

Cold Bending :

Quenched & Tempered steels can be readily cold formed however the power required will be higher (70%) than that for mild steel of the same thickness.  It is recommended that the largest possible bending radius should be used, and generally the inside radius should not be less that 3 times the plate thickness.

Bend axis vs. rolling direction Minimum inside bending radius Minimum die opening
Perpendicular 3t 8.5t
Parallel 4t 10t


Weldability and Toughness :

(CEV (%)
Impact Values
8<t<30 0.43 27J @ -45°C
30<t<40 0.52 27J @ -45°C
40<t<100 0.57 27J @ -45°C
100<t<130 0.61 27J @ -45°C


Mechanical Properties

MPa min
% min
8 – 70mm 690 790 – 930 18
Above 70mm 630 690 – 930 18


To find out more about Triton Alloys Inc Services and our Range of “Quenched & Tempered Steel Plates” which we can supply directly to you, Click Here to Contact Us.