Steel casting

Steel casting is a specialized form of casting involving various types of steel. Steel castings are used when cast irons cannot deliver enough strength or shock resistance.[1]

Examples of items that are steel castings include: hydroelectric turbine wheels, forging presses, gears, railroad truck frames, valve bodies, pump casings, mining machinery, marine equipment, turbocharger turbines and engine cylinder blocks.[1]

Steel castings are categorized into two general groups: carbon steels and alloy steels.[1]

Steel castability

Steel is more difficult to cast than iron. It has a higher melting point and greater shrinkage rate, which requires consideration during mold design. Risers should be given more capacity to draw from as the metal cools and shrinks. Attention should be paid to the thickness of mold cavities, as thinner areas will cool quicker than thicker areas, which can create internal stress points that can lead to fracture.

Molten steel is also less fluid than molten iron, making it more difficult to pour and fill intricate gaps in a mold cavity. Molten steel is also more likely to react with internal mold surfaces, making for more unpredictable results.


Cast parts often require machining to achieve accurate tolerances and desired surface finishes. Carbon steel is the easiest type of steel to machine. High-carbon steel can be more time consuming to cut or grind, and will wear tools faster. Low-carbon steel can get gummy, making it difficult to work with.

Generally, the presence of alloys used to increase mechanical performance often make machining more difficult.

Damping ability

Casting is often a valuable means to creating intricate parts used in machine applications where vibration is often a factor. Cast steel typically has a lower damping ability than cast iron, which can lead to excess vibration and noise in the form of ringing or squealing.

Impact and wear resistance

Most steels offer a good balance of strength and ductility, which makes them extremely tough. This allows them to withstand significant stress and strain without fracturing. Steel can also be fairly wear-resistant. Alloy additions can increase both impact and wear resistance.[3]

Steel casting alloys

Alloy steel castings are broken down into two categories: low-alloy steels and high-alloy steels.[4] Low-alloy steels contain less than 8% alloying content and high-alloy steels have 8% or more.[4]

This is a table of some steel casting alloys:

Heat resistant steel castings per ASTM A297-1981[4]
Grade Nominal alloy composition (%wt) Tensile strength, minimum Yield strength to 0.2%, minimum Elongation, minimum, from 2 in, 51 mm (%)
(ksi) (MPa) (ksi) (MPa)
HC28 Cr55380---
HD28 Cr, 5 Ni75515352408
HF19 Cr, 9 Ni704853524025
HH25 Cr, 12 Ni755153524010
HI28 Cr, 15 Ni704853524010
HK25 Cr, 20 Ni654503524010
HL29 Cr, 20 Ni654503524010
HN20 Cr, 25 Ni63435--8
HP26 Cr, 35 Ni62.5430342354.5
HT15 Cr, 35 Ni65450--4
HU19 Cr, 39 Ni65450--4
HW12 Cr, 60 Ni60415---
HX17 Cr, 66 Ni60415---
Corrosion resistant steel castings per ASTM A743-1981a[5]
Grade Nominal alloy composition (%wt) Tensile strength, minimum Yield strength to 0.2%, minimum Elongation, minimum, from 2 in, 51 mm (%)
(ksi) (MPa) (ksi) (MPa)
CF-89 Cr, 9 Ni704853020535
CG-1222 Cr, 12 Ni704852819535
CF-2019 Cr, 9 Ni704853020530
CF-8M19 Cr, 10 Ni, with Mo704853020530
CF-8C19 Cr, 10 Ni, with Nb704853020530
CF-16 &
19 Cr, 9 Ni, free machining704853020525
CH-10 &
25 Cr, 12 Ni704853020530
CK-2025 Cr, 20 Ni654502819530
CE-3029 Cr, 9 Ni805504027510
CA-15 & CA-15M12 Cr906206545018
CB-3020 Cr6545030205-
CC-5028 Cr55380---
CA-4012 Cr1006907048515
CF-319 Cr, 9 Ni704853020535
CF-3M19 Cr, 10 Ni, with Mo704853020530
CG-8M19 Cr, 11 Ni, with Mo755203524025
CN-7M20 Cr, 29 Ni, with Co & Mo624252517035
CN-7MS19 Cr, 24 Ni, with Co & Mo704853020535
CW-12MNi, Mo & Cr72495463154
CY-40Ni, Cr & Fe704852819530
CA-6NM12 Cr, 4 Ni1107758055015
CD-4MCu25 Cr, 5 Ni, 3 Cu, 2 Mo1006907048516
CA-6N11 Cr, 7 Ni14096513593015



  1. Oberg, p. 1332
  2. "Machining Cast Iron Components | Modern Casting | AFS". Retrieved 2016-07-07.
  3. "Understanding Material Specifications for Steel Castings | AFS". Retrieved 2016-07-07.
  4. Oberg, p. 1334
  5. Oberg, p. 1335


  • Oberg, Erik; Jones, Franklin D.; Horton, Holbrook L.; Ryffel, Henry H. (2000), Machinery's Handbook (26th ed.), New York: Industrial Press Inc., ISBN 0-8311-2635-3.
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