Tool steels

tool-steels

6 materials across 1 types

About tool steels

Tool steels (D2, P20): hardness and strength by heat treatment, with sources.

Tool steels are alloy steels made for cutting, forming and moulding. Their hardness and toughness are set by the hardening and tempering temperatures, which every value here names.

At a glance

Highest yield strength: AISI H13 hot-work tool steel reaches 1,520 MPa. Lowest: 1.2738 plastic mould steel starts at 826 MPa. (3 of 6 grades have a sourced value.)
Highest tensile strength: AISI H13 hot-work tool steel reaches 1,820 MPa. Lowest: P20 plastic mould steel starts at 965 MPa. (4 of 6 grades have a sourced value.)

Ranges run across the conditions each source reports (temper, heat treatment, form), measured at room temperature where the source says so.

How they compare

The same measurements for every material in the collection. A range means the grade has values under several conditions; "at least" means the source gives a specified minimum. "no data" means no sourced value yet. For ranked tables, open a benchmark.

Tool steels: how the grades compare
Material	Yield strength	Tensile strength	Density	Young's modulus	Thermal conductivity	Melting point
AISI D2 cold-work tool steelcold-work tool steel	no data	no data	7.7 to 8 g/cm³	190 to 210 GPa	20 W/(m·K)	no data
P20 plastic mould steelplastic mould steel	827 to 862 MPa	965 to 1,030 MPa	7.83 to 7.86 g/cm³	190 to 210 GPa	32.5 W/(m·K)	no data
1.2316 stainless plastic mould steelstainless plastic mould steel	no data	1,100 MPa	7.7 g/cm³	no data	23.5 W/(m·K)	no data
1.2738 plastic mould steelplastic mould steel	826 MPa	993 to 1,100 MPa	7.8 g/cm³	205 GPa	29 to 34.5 W/(m·K)	no data
A2 air-hardening cold-work tool steelcold-work tool steel	no data	no data	7.86 g/cm³	190 to 210 GPa	no data	no data
AISI H13 hot-work tool steelhot-work tool steel	1,280 to 1,520 MPa	1,420 to 1,820 MPa	7.8 g/cm³	210 GPa	25 W/(m·K)	no data

What these materials are made of

Composition by weight, as printed in the sources for each grade (the first constituents listed).

Composition of each grade
Material	Main constituents
AISI D2 cold-work tool steel	Fe balance · C 1.4 to 1.6% · Si 0.1 to 0.6% · Mn 0.1 to 0.6% · Cr 11 to 13% · Mo 0.7 to 1.2% · V 0.5 to 1.1%
P20 plastic mould steel	Fe balance · C 0.28 to 0.4% · Mn 0.6 to 1% · Si 0.2 to 0.8% · Cr 1.4 to 2% · Mo 0.3 to 0.55% · Cu up to 0.25%
1.2316 stainless plastic mould steel	Fe balance · C 0.33 to 0.45% · Si up to 1% · Mn up to 1.5% · P up to 0.03% · S up to 0.03% · Cr 15.5 to 17.5%
1.2738 plastic mould steel	Fe balance · C 0.35 to 0.45% · Si 0.2 to 0.4% · Mn 1.3 to 1.6% · Cr 1.8 to 2.1% · Mo 0.15 to 0.25% · Ni 0.9 to 1.2%
A2 air-hardening cold-work tool steel	Fe balance · C 0.95 to 1.05% · Mn 1% · Si 0.5% · Cr 4.75 to 5.5% · Mo 0.9 to 1.4% · V 0.15 to 0.5%
AISI H13 hot-work tool steel	Fe balance · C 0.39% · Si 1% · Mn 0.4% · Cr 5.2% · Mo 1.4% · V 0.9%

Where they are used

Uses
Use	Grades
Blanking, fine-blanking, punching, cropping, shearing and trimming tools	AISI D2 cold-work tool steel
Thread-rolling dies and cold-extrusion dies	AISI D2 cold-work tool steel
Shear blades, planer blades and industrial cutting tools	AISI D2 cold-work tool steel
Plastic injection-mould cavities, cores and inserts	P20 plastic mould steel
Mould frames, bolsters and die holders	P20 plastic mould steel
Zinc die-casting dies and pressure-casting dies	P20 plastic mould steel
Plastic moulds, extrusion tools and press moulds for corrosive plastics	1.2316 stainless plastic mould steel
Shafts, spindles, bolts, pistons, valves and pump parts	1.2316 stainless plastic mould steel
Injection and blow moulds for PVC and gas-releasing plastics	1.2316 stainless plastic mould steel
Plastic injection-mould cores and cavities	1.2738 plastic mould steel
Large plastic mould blocks and mould frames	1.2738 plastic mould steel
Die-casting moulds, dies, forging and metal extrusion tools	1.2738 plastic mould steel
Blanking and forming punches, trimming dies, thread-rolling dies and injection-molding dies	A2 air-hardening cold-work tool steel
Shear blades, cutting, punching and stamping tools, bending tools, form rolls, cold pilger mandrels, plastic moulds and embossing dies	A2 air-hardening cold-work tool steel
Die-casting dies for tin, lead and zinc alloys, and for aluminium and magnesium alloys	AISI H13 hot-work tool steel
Fixed inserts, cores and sprue parts for die casting	AISI H13 hot-work tool steel

When each grade fits

Best use and weak spots of each grade
Material	Best for	Weakest at
AISI D2 cold-work tool steel	Blanking, punching, forming and cutting tools that need high wear resistance more than toughness	Toughness and corrosion: rather limited cracking resistance (Uddeholm), and corrosion resistance below that of stainless steel (Wikipedia)
P20 plastic mould steel	Plastic injection-mould blocks, mould frames and bolsters that are machined in the pre-hardened condition and then polished (Smith Metal Centres; Oberste-Beulmann; Abrams).	Corrosion resistance. The datasheets say it is not corrosion resistant and rusts unless protected; Aços Formosa points PVC and gas-releasing plastics to the stainless grade 1.2316 instead.
1.2316 stainless plastic mould steel	Moulds and tools for PVC and other corrosive plastics that need a stainless, polishable face in the quenched and tempered condition (Aços Formosa; Dörrenberg; Abrams).	Corrosion data are qualitative: no test is printed, and the stated range is atmospheric, humid, weak acid and alkali service (Abrams). Machinability is rated only 2 on a 1 to 6 scale (Abrams).
1.2738 plastic mould steel	Large plastic injection-mould blocks, cores and frames that are machined in the supplied condition and then polished, and hydroforming tools and dies (Dörrenberg; Industeel; Oberste-Beulmann; Abrams).	Corrosion resistance. Abrams says the grade has a certain degree of corrosion resistance but is not stainless: 1.8 to 2.1 percent chromium is far below the 10.5 percent it gives as the minimum for stainless steel. Reheating or tempering at 600 °C or above lowers hardness.
A2 air-hardening cold-work tool steel	Blanking, punching, trimming and forming tools that need good dimensional stability and wear resistance	Corrosion, hardness after tempering and impact toughness: the sources read here give no numbers for these
AISI H13 hot-work tool steel	Die-casting, extrusion and forging tools that run hot and need hardness, strength at elevated temperature and resistance to heat checking	Corrosion: no corrosion rating or test for H13 was found in the fetched sources. Uddeholm also warns that tempering between 425 and 550 °C causes temper brittleness.