AR500 is a quenched and tempered abrasion resistant steel plate with a nominal Brinell hardness of approximately 500 HBW. The designation AR stands for abrasion resistant, and the number 500 refers to the nominal hardness level. AR500 is intended for components that are exposed to severe wear, impact, and sliding contact, where ordinary structural steel would wear out quickly. This article explains the meaning, properties, typical applications, and fabrication limits of AR500 plate.
Hardness and Mechanical Properties
AR500 achieves its hardness through quenching and tempering. The nominal hardness is about 500 HBW, and plates in the 3 mm to 80 mm thickness range are typically supplied with hardness in the range of 470 to 540 HBW, depending on thickness and producer practice. The high hardness gives the plate a tensile strength of approximately 200,000 psi (about 1380 MPa) as a typical value, with yield strength in the range of 160,000 to 190,000 psi (about 1100 to 1310 MPa). Elongation is typically 8 to 10 percent in 2 inches, which is low compared with structural steels and indicates limited ductility. Density is approximately 7.85 g/cm3, the same as most carbon and low alloy steels.
Available Plate Forms and Sizes
AR500 is available as hot rolled and quenched and tempered plate, and can be supplied in sheets, cut-to-size shapes, and pre-drilled liners. Typical thicknesses range from 3 mm to 80 mm, with wider and thicker plates available on request. Plates can be supplied with a mill edge or cut edge, and with or without surface grinding. Dimensional tolerances are generally in line with standard plate specifications for abrasion resistant steels.
Typical Applications
Because of its extreme hardness, AR500 is used in industries where abrasive wear is the dominant failure mode. In mining, it is used for bucket liners, chute liners, hopper liners, and crusher wear parts. Dump trucks use AR500 for body linings and floor plates. Agricultural machinery applies it to plows, tillers, and drag plates, while earthmoving equipment uses it for blades, guards, and excavator components. In the defense sector, AR500 is used for armor plates in vehicles and structures, and in shooting applications it is a common material for steel targets because it resists projectile deformation and fragmentation. In wear service, AR500 can outperform mild steel by roughly four to six times, depending on the abrasion conditions.
AR500 Compared with AR400
The table below compares AR500 with the lower hardness AR400 grade.
Property / AR400 / AR500: nominal hardness - about 400 HBW / about 500 HBW; toughness - higher / lower; weldability - easier, more forgiving / requires more care; wear resistance - moderate / extreme; typical applications - general wear parts, chutes, buckets / ballistic protection, mining liners, targets.
In practice, AR500 is chosen when the wear rate of AR400 is unacceptable, while AR400 is preferred where impact toughness or forming and welding are important. The selection should be based on the actual wear mechanism, because very hard plates can be more sensitive to impact spalling in some service conditions.
Fabrication Considerations
AR500 can be cut by plasma or waterjet; oxy-fuel cutting is possible but requires careful preheating because of the high carbon content. Cold forming is possible with generous bend radii, and springback is larger than for structural steel because of the high yield strength. Hot forming should be avoided because it can reduce the hardness; if the plate is heated above the tempering temperature, the abrasion resistance is lost. Welding of AR500 is difficult and is normally limited to attachment welds using low-hydrogen consumables with preheat and controlled heat input. Welded areas lose hardness in the heat-affected zone, so wear protection at the joint is often restored with hardfacing. Where possible, mechanical fastening with countersunk bolts is preferred over welding for attaching liners.
Frequently Asked Questions
What does the designation AR500 mean?
AR stands for abrasion resistant, and 500 refers to the nominal Brinell hardness of about 500 HBW.
What is the hardness range of AR500 plate?
The nominal hardness is 500 HBW, with typical supplied values in the range of 470 to 540 HBW depending on thickness and producer practice.
Can AR500 be welded?
Yes, but only with precautions: low-hydrogen consumables, preheat, controlled heat input, and often post-weld heat treatment. The heat-affected zone will lose hardness, so weld areas may need hardfacing.
Can AR500 be formed?
Cold forming is possible with generous bend radii and allowance for springback. Hot forming above the tempering temperature must be avoided because it reduces hardness.
What is the tensile strength of AR500?
The tensile strength is approximately 200,000 psi (about 1380 MPa) as a typical value, with yield strength of 160,000 to 190,000 psi (about 1100 to 1310 MPa).
Is AR500 suitable for ballistic armor?
AR500 is used in armor plates intended to meet ballistic protection levels such as Level III and IV. The complete armor system, including backing and mounting, must be validated against the relevant test standard.