Micro-structure of ASTM A532 Class II Type D machined, hardened structure liner.

High Chrome White Iron – Abrasion Resistant Cast Irons

Abrasion Resistant Cast Irons ASTM A532

The ASTM A532 specification refers to a group of high chrome white cast irons that have been engineered to offer high abrasion resistance to gouging. These alloys are particularly effective in industries such as the Oil Sands, mining, recycling and hydraulic fracturing.

At Penticton Foundry we work in partnership with you to find solutions to your wear problems.  Based on your requirements and feedback we design and engineer an alloy that fully meets the ASTM A532 Standard.  In doing so we maximize your run-time and reduce the number of stoppages and change outs.  Our abrasion resistant cast irons can be supplied in a variety of compositions and hardness.  Depending on your needs, Penticton Foundry can cast to finished size and/or fully machine your component. If you’re wondering why chrome white iron (ASTM A532) is so abrasion resistant, read this.

ASTM A532 Class III Type A

These alloys are usually called high chrome white irons, and contain between 11% and 30% Cr, as well as other elements, to promote the presence of carbides in their microstructure.

By altering chemistry and processing, the hardness levels have a wide range, allowing Penticton Foundry to design exactly what is needed.

ASTM A532, high chrome white iron, is highly abrasion resistant, and so shines in applications involving wear, or a combination of wear and corrosion/oxidation.

Pliant 25

This alloy is softenable to allow for drilling, tapping and broaching. The chemistry, processing and heat treatment of this alloy make it the perfect choice when you need to drill, tap and/or broach. After these machining operations, it can be hardened (typically to >600 BHN) before being put into use. It is especially useful for pump or hydraulic fracturing components like volutes, impellers and liners.

Learn More: Pliant25 Class III Type A (Pliant25 Class 3 Type A)


Granite 25 is our most common alloy, and is typically supplied at a hardness >650 BHN. It is used across all industries any time there is a need for abrasion resistance. It is used for pumping slurries in the mining, Oil Sands and other industries. It is also used for crushing applications in mining, the Oil Sands, recycling and other industries.

Learn More: Granite25 ASTM A532 Class III Type A (Granite25 ASTM A532 Class 3 Type A)


This alloy has the highest percentage of carbides, and therefore, a hardness that usually exceeds 680 BHN. It is typically found in the mining and recycling industries for parts like chute liners and blow bars.

Learn More: Diamond25 ASTM A532 Class III Type A (Diamond25 ASTM A532 Class 3 Type A)


This grade of ASTM A532 is alloyed to increase the toughness and through-hardness in thick section castings. It is particularly useful in applications like a gyratory crusher in the mining industry, or any pulverizer that crushes abrasive media.

Learn More: Tough25 ASTM A532 Class III Type A (Tough25 ASTM A532 Class 3 Type A)

Other Abrasion Resistant Alloys

The ASTM A532 specification has several other types/grades that have different chemistries and properties. See below for details.

Nihard 1 (Class I Type A)

This alloy has been in production for the longest of any of the abrasion resistant alloys. It contains nickel and chromium and can be very cost effective, depending on the current price of these commodities. Nihard 1 is used in wear-applications, and is especially useful when transporting mixed cement.

Learn More: Nihard ASTM A532 Class I Type A (Nihard ASTM A532 Class 1 Type A)

15-3 (Class II Type B)

This alloy has a slightly higher toughness, due to the reduction in the amount of carbides in the matrix. It is a good choice in the mining industry, for applications like ball mill liners. It is also used in dredging components, as well as in roller crushers and pulverizers.

Learn More: 15-3 ASTM A532 Class II Type B (15-3 ASTM A532 Class 2 Type B)

20-1 (Class II Type D)

This alloy is as hard as the 25% Cr alloy, but with a little more toughness, and a little less corrosion resistance. The hardness is maintained by the addition of molybdenum. It is a good choice for the mining and crushing industries, where thicker castings are used.

Learn More: 20-1 ASTM A532 Class II Type D (20-1 ASTM A532 Class 2 Type D)

30% Cr

30% chrome white iron is the most corrosion resistant of the ASTM A532 iron alloys. It has found a real niche in flue-gas desulfurization, as well as other oxidizing environments and some reducing environments. It is not as abrasion resistant as the other high chrome white iron alloys.

Learn More: ASTM A532 Data Sheet 30% Cr

Unique Alloy – Pliant25 ASTM A532 Class III Type A

We are proud to offer Pliant25 ASTM A532 Class III Type A which is the best alloy that can be used when drilling, tapping and broaching is required.  After machining it is heat treated to approximately 600 BHN.