ThePipingMart Blog Grades H42 Tool Steel – Composition, Properties and Uses

H42 Tool Steel – Composition, Properties and Uses

Tool Steel H42

Tool Steel H42 is a versatile, all-purpose metal often used for projects requiring strength and durability. It has excellent corrosion resistance, heat resistance, and machinability properties. It can be heat treated to increase its hardness and wear resistance, and it is relatively easy to machine. H42 Tool Steel is a highly sought-after material across industries for its exceptional properties and utility. It is known among technical experts as UNS T20842 or SAE-AISI H42 steel, an alloy widely used for making cutting tools, dies, and gauges. Its composition includes high carbon, chromium, and tungsten content, making it extremely hard, durable, and resistant to wear and tear. Besides its remarkable mechanical properties, H42 Tool Steel is also known for its resistance to corrosion, high-temperature applications, and ability to maintain its shape and strength even under strenuous usage. With its unique properties, H42 Tool Steel is a go-to material for various industrial applications. Let’s take a closer look at this amazing metal and why it is a great choice for any project.

What Forms of H42 Tool Steel is Available at Piping Mart?

  • Nut
  • Bar
  • Bolt
  • Pipe
  • Screw
  • Tubing
  • Valves
  • Washers
  • Flanges
  • Fasteners
  • Electrodes
  • Stud Bolts
  • Sheet Plates
  • Pipe Fittings
  • Forged Fitting
  • Instrumentation Fittings

H42 Tool Steel Composition

Element Content (%)
C 0.55-0.70
Mn 0.15-0.40
Cr 3.75-4.50
Ni 0.3
Mo 4.50-5.50
W 5.50-6.75
V 1.75-2.20
Cu 0.25
P 0.03
S 0.03

H42 Tool Steel Physical Properties

Properties Metric Imperial
Density 8.15 g/cc 0.294 lb/in3

H42 Tool Steel Mechanical Properties

Properties Metric Imperial
Hardness, Rockwell C 50.0 – 60.0 50.0 – 60.0
Poisson’s ratio (25°C) 0.27-0.30 0.27-0.30
Elastic modulus 190-210 GPa 27557-30458 ksi

H42 Tool Steel Thermal Properties

Properties Conditions
T (°C) Treatment
Thermal expansion 11.9 x 10-6/ºC 20-540

H42 Tool Steel Equivalents

  • ASTM A681
  • UNS T20842
  • FED QQ-T-570

H42 Tool Steel Uses

Tool Steel H42 has many uses in the industry due to its versatility. It is commonly used in the aerospace, automotive, medical, and military industries due to its superior strength and machinability properties. This makes it ideal for use in aircraft components, engine parts, surgical implants, firearm components, and much more. It can also be used in the manufacture of tools such as drills, knives, saw blades, punches, dies, taps etc., making it ideal for use in machine shops and other industrial applications.

H42 Tool Steel Uses in Industries

Automotive Industry

H42 tool steel is commonly used in the automotive industry for its high strength and wear resistance. It is often used to make parts such as gears, shafts, and bearings subjected to heavy loads and frequent use.

Aerospace Industry

The aerospace industry also utilizes H42 tool steel to withstand extreme temperatures and high-stress conditions. This makes it popular for manufacturing aircraft engine components, landing gear, and other critical parts.

Oil and Gas Industry

In the oil and gas industry, H42 tool steel is used for drilling tools due to its toughness and resistance to wear and corrosion. It also produces valves, pumps, and other equipment that must withstand harsh environments.

Manufacturing Industry

Many manufacturing processes require tools made from H42 tool steel due to its excellent machinability and durability. This includes industries such as metalworking, plastic injection molding, and die casting.

H42 Tool Steel Corrosion Resistance

Tool Steel H42 has excellent corrosion resistance thanks to its high chromium content, which helps to protect against rusting and pitting caused by exposure to moisture or harsh chemicals. This makes it a great choice for applications where resistance to corrosion is essential such as valve bodies or pump components used in chemical processing plants or marine environments. Additionally, Tool Steel H42 is resistant to atmospheric oxidation, which means it will not corrode when exposed to air over long periods of time like some other metals would.

H42 Tool Steel Heat Treatment & Machining

Tool Steel H42 can be heat treated to increase its hardness and wear resistance, making it perfect for applications that require extra protection from wear or impact damage, such as cutting tools or drill bits that are subject to frequent use or heavy loads. Additionally, Tool Steel H42 can be machined with relative ease compared to other tool steels due to its low carbon content, which prevents warping during the machining process. This makes it ideal for intricate designs such as moulds or jigs that need precise details but still require strength and durability.


Tool Steel H42 is an extremely versatile metal with a wide range of uses due to its superior strength and wear resistance properties combined with excellent corrosion resistance qualities. Its ability to be heat treated increases its hardness even further while still being relatively easy to machine compared with other tool steels making it perfect for any project requiring strength and durability without sacrificing precision detail work. For these reasons—and many more—it’s no wonder why this metal remains one of the most popular choices amongst professionals across multiple industries worldwide!

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