Support ISO H

ISO H

What is the ISO H Material Group?

The ISO H material group consists of steels and cast irons that are hardened or tempered, with hardness ranging from 45–65 HRc. This also includes chill cast irons with hardness around 400–600 HB. Hardened steels and tempered steels are especially resistant to wear and abrasion, making them suitable for applications where materials are subjected to high mechanical stresses and intense wear.

Why are H materials important?

Hardened and tempered steels are essential in many industrial applications due to their outstanding wear resistance and durability. Their ability to withstand repeated stress and heavy loads without damage or failure makes them very popular in heavy industry, the automotive sector, and tool manufacturing. Hardened steels also offer better resistance to rust and corrosion than ordinary steel products, giving them a longer service life in demanding environments.

Special Features of the H Material Group

The ISO H material group includes steels and cast irons that are extremely hard and resistant to abrasion. These materials are used in applications that require high mechanical strength and excellent resistance to wear.

Common grades and their properties:

High Carbon Steels (~60 HRc):

  • Properties: High hardness and wear resistance, good mechanical strength.
  • Applications: Blades, springs, tools.

Bearing Steels (~60 HRc):

  • Properties: High strength, excellent wear resistance.
  • Applications: Bearings, shafts, connecting rods.

Tool Steels (~68 HRc):

  • Properties: Extremely hard, high wear resistance, commonly used instead of grinding.
  • Applications: Shears, drill bits, punches.

White Cast Iron (~50 HRc):

  • Properties: Durable against wear, used at high temperatures.
  • Applications: Wear parts, agricultural machinery components.

Austempered Ductile Iron (ADI) (~40 HRc):

  • Properties: Good toughness, high mechanical strength.
  • Applications: Machine components, shafts, gears.

Industry Segments and Component Applications

Hardened steels and cast irons included in the ISO H material group are widely used in many industrial applications due to their outstanding durability. Here are some key industry segments and examples of applications:

Automotive Industry

Applications:

  • Transmission shafts: High mechanical strength and wear resistance.
  • Steering gear gears: Resistance to repeated stress.
  • Cylinder heads: Wear resistance and corrosion resistance.

Tool Industry

Applications:

  • Hand tools: Strong and durable cutting tools.
  • Drill bits: High hardness and wear resistance.
  • Knives and punches: Extremely hard, excellent cutting capability.

Construction and Heavy Industry

Applications:

  • Drilling equipment: Mechanical strength and wear resistance.
  • Hand and power tools: Resistant to wear and highly durable.

Machinability and Weldability of the ISO H Material Group

  • Machinability: Hardened steels are difficult to machine due to their high hardness. Machining is often performed as a finishing operation and requires special tools, such as CBN cutting materials and ceramic composites. Cutting forces and power requirements are high, and chip control is generally good but demands special attention from experienced machinists.
  • Weldability: Hardened and tempered steels can be welded, but their high hardness and alloy elements make it challenging. Welding may require special procedures, pre-heating, and specific welding methods to avoid cracking.

Tips for Working with ISO H Materials

  • High mechanical loads: When working with these materials, focus on managing high mechanical loads (to prevent chipping, cratering, or tool breakage).
  • Appropriate depth of cut and feed: Use shallow or moderate depth of cut and feed to ensure optimal machining processes.
  • Balanced cutting speed: Balance the cutting speed to achieve optimal tool life and process economics.
  • Use of suitable carbide grades: Use specific carbide grades or CBN and cermet inserts, as well as robust cutting geometry, to achieve the best results.
  • Cooling: Emulsion cooling (with 4%–6% concentration) is recommended for health reasons and to ensure process stability.

Summary

The ISO H material group consists of hardened and tempered steels as well as hard cast irons, which are essential in many industrial applications where high mechanical strength and wear resistance are required. These materials are challenging to machine and weld due to their high hardness and abrasive nature. However, with the right tools and techniques, they offer excellent performance and long service life. It is important for machinists and workshops to thoroughly understand these materials and master machining processes to achieve high-quality and cost-effective results. This makes ISO H materials critical for many industries, especially automotive, tool manufacturing, and heavy industry.