Grade H43 Tool Steel (UNS T20843)

Topics Covered

Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
     Forging
     Annealing
     Stress Relieving
     Hardening
     Quenching
     Tempering
Applications

Introduction

Tool steels are high-quality steels that have good hardness, abrasion resistance and good machinability. They are generally used in a heat-treated state. Tool steels are used for special applications such as injection molding, plastic molding, die casting, extrusion and forging.

AISI H43 tool steels are high vanadium-moly chrome premium hot working steel having excellent abrasion and heat resistance. The following section will provide an overview of the grade H43 tool steels.

Chemical Composition

The chemical composition of H43 tool steels is outlined in the following table.

Element Content (%)
Molybdenum, Mo 7.75-8.5
Chromium, Cr 3.75-4.5
Vanadium, V 1.8-2.2
Carbon, C 0.5-0.65
Silicon, Si 0.2-0.45
Manganese, Mn 0.15-0.4
Phosphorus, P 0.03
Sulfur, S 0.03

Physical Properties

The following table shows the physical properties of H43 tool steels.

Properties Metric Imperial
Density 7.7 g/cm3 0.278 lb/in3
Melting point 1450-1510°C 2642-2750°F

Mechanical Properties

The mechanical properties of H43 tool steels are displayed in the following table.

Properties Metric Imperial
Tensile strength 650-880 MPa 167.95 ksi
Elongation 8-25% 15%
Modulus of elasticity 190-210 GPa 27557- 30457 ksi
Poisson’s ratio 0.27-0.3 0.27-0.3

Thermal Properties

The thermal properties of H43 tool steels are given in the following table

Properties Metric Imperial
Thermal expansion co-efficient 10 µm/m°C 5.5 µin/in°F
Thermal conductivity 25 W/mK 173 BTU.in/hrft².°F

Fabrication and Heat Treatment

Forging

Analyze Your Metals | Request a Quote

H43 tool steels are forged slowly and uniformly at 3092 - 3272°C (1700-1800°F). The material is cooled slowly in lime, mica or dry ashes when dried.

Annealing

H43 tools steels are annealed slowly at 2732 - 2822°C (1500-1550°F) followed by slow cooling to about 1832°C (1000°F).

Stress Relieving

The annealed materials are then stress relieved by heating at 2102 - 2282°C (1150-1250°F), allowed to equalize and cooled in still air.

Hardening

The materials are transferred to the hardening furnace operating at 3902 - 3992°C (2150-2200°F) based on the degree of hardening required for specific applications.

Quenching

H43 tool steels are quenched in air, oil or molten salt bath at 1832 - 2012°C (1000-1100°F).

Tempering

Tempering is usually carried out at 1832 - 2012°C (1000-1100°F), but the temperature can be varied according to the desired hardness.

Applications

H43 tool steels are mainly used for severe hot work applications such as forming rolls, dies and punches where abrasion and wash resistance is required.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit