Buy Tool Steels Online in Australia
Tool Steel Grade Selection — Quick Reference
Tool steels are high-performance alloy steels used to manufacture cutting tools, dies, moulds, and high-wear components. Each grade balances hardness, toughness, wear resistance, and dimensional stability under heat treat. Choosing the wrong grade = premature failure, dimensional drift, or expensive rework.
| Grade | Hardening Type | Best For | Hardness (HRc) |
|---|---|---|---|
| A2 | Air hardening | General-purpose cold-work dies — the workshop everyday die steel | 58 – 62 |
| D2 | Air hardening | High wear cold-work dies — blanking, forming, stamping | 58 – 62 |
| O1 | Oil hardening | Cold-work tools — punches, knives, simple dies | 58 – 62 |
| P20 | Pre-hardened | Plastic injection moulds, die holders — ready-to-machine | 28 – 32 (pre-hard) |
| S7 | Air / Oil hardening | Shock-resistant tools — punches, chisels, breakers | 54 – 58 |
| H13 | Air hardening | Hot-work dies — die-casting, forging, extrusion | 44 – 52 |
| M2 (HSS) | High-speed steel | Cutting tools — drills, taps, milling cutters, broaches | 62 – 65 |
| 4140 (alloy) | Through-hardening | General engineering — shafts, gears, axles, structural | 28 – 50 |
Selection logic: Wear vs Toughness is the master trade-off. D2 + M2 = high wear but brittle; S7 + 4140 = tough but lower wear. Air-hardening = lower distortion than oil/water hardening. Pre-hardened P20 = no heat treat required (saves cycle time). Companion: key steel, bronze bars, raw materials.
Tool Steels for Australian Toolmaking, Die Manufacture & Industrial Applications
Tool steels are the high-performance alloy steels used to manufacture cutting tools, dies, moulds and high-wear industrial components — the steels that produce the rest of manufactured products. Each tool steel grade balances specific properties: hardness, toughness, wear resistance and dimensional stability under heat treatment. For Australian toolmakers, die makers and industrial manufacturers producing or replacing tooling and high-wear components, matching the right tool steel to the application is essential. AIMS Industrial supplies tool steels in standard grades and formats for trade and industrial customers across Australia.
Browse related engineering materials at AIMS:
- Tool steels — this page — A2, D2, O1, P20, S7, H13, M2, 4140
- Key steel — precision-ground keyway stock, metric & imperial
- Bronze bars — phosphor bronze for bearing applications
- Raw materials — full engineering material range
The tool steel grades we stock
- A2 (air hardening) — general-purpose cold-work tool steel; good wear resistance with reasonable toughness; the everyday die steel
- D2 (high-chromium) — high wear resistance for blanking dies, forming dies and abrasive applications
- O1 (oil hardening) — economical general tool steel; suits hand-finishing tools, jigs and fixtures
- P20 (pre-hardened) — supplied pre-hardened to 28-32 HRC for plastic injection moulds
- S7 (shock-resistant) — high impact toughness for chisels, punches and impact tooling
- H13 (hot-work) — for tooling exposed to elevated temperature: extrusion dies, die-casting tooling, hot-forging dies
- M2 (high-speed) — for cutting tools requiring red-hardness; alternative to HSS in custom toolmaking
- 4140 / 4340 (alloy steels) — pre-hardened alloy steels for shafts, gears and general machine components
Choosing the right tool steel
- Cold-work cutting and forming dies — A2 (general), D2 (high wear), O1 (economical)
- Plastic injection moulds — P20 (pre-hardened, machinable)
- Impact tooling and shock applications — S7 (high toughness)
- Hot-work tooling — H13 (hot-work specific)
- Cutting tools (custom toolmaking) — M2 (high-speed steel)
- Machine components and shafts — 4140, 4340 (pre-hardened alloy)
Heat treatment considerations
Most tool steels require heat treatment after machining to develop their final hardness and properties. Different grades use different hardening processes:
- Air hardening (A2, D2, S7, H13) — heat to austenitising temperature, cool in still air; minimal distortion
- Oil hardening (O1) — quench in oil after austenitising; some distortion typical
- Pre-hardened (P20, 4140 PHT) — supplied at working hardness; no further heat treatment required
For production work, use a competent commercial heat treater — the equipment, expertise and process control required for consistent results is significant. For quick prototype work, in-house oven heat treatment is possible for some grades.
Where tool steels earn their place
- Punch and die manufacture — blanking, piercing, forming, drawing dies
- Plastic and rubber moulds — injection moulds, compression moulds, cavity tooling
- Cutting tools — custom blades, knives, shear blades and specialised cutters
- Wear components — abrasion-resistant industrial parts
- Fixtures and jigs — toolroom fixtures requiring dimensional stability
- Impact tools — chisels, punches and percussion tools
Available formats
Tool steels are stocked in standard formats: round bar (turned and ground or as-rolled), flat bar (precision-ground or as-rolled), square bar and plate. Pre-hardened grades are typically supplied at working hardness; air-hardening and oil-hardening grades are typically supplied annealed (soft) for machining, then heat-treated after roughing. Match the format to the application requirement.
Companion ranges at AIMS
Tool steels sit alongside our broader engineering material and toolmaking range. For complementary materials, see key steel and bronze bars. For machining and tooling, see measuring tools, carbide drill bits, cobalt drill bits, milling inserts and the threading range. The full engineering material range is catalogued under raw materials.
For tool steel grade selection, format and heat treatment guidance for specific tooling, mould or wear applications, call (02) 9773 0122 or contact our team.
People Also Ask — Tool Steels
Q: What tool steels does AIMS stock?
AIMS stocks selected tool steels for workshop tooling and die work: O1 (oil-hardening tool steel, general workshop), A2 (air-hardening, low-distortion), D2 (high-chromium air-hardening, wear resistance), and specialty alloys per customer requirement. Tool steels are heat-treatable to high hardness — used for cutting tools, dies, punches, jigs, and wear parts. AIMS supplies in rod, bar, plate, and pre-hardened forms. For specific tool steel grades or large quantities, contact AIMS — many specialty grades available on indent.
Q: O1, A2, or D2 tool steel?
O1 (oil-hardening): general workshop tool steel — economical, easy to machine in annealed state, hardens with oil quench. Good for one-off tooling, gauges, light cutting tools. A2 (air-hardening): low-distortion hardening (cools in air, less warping), better for precision parts. Good for stamping dies, jigs, fixtures. D2 (air-hardening high-chromium): highest wear resistance of the three, harder to machine. Good for cold-work dies, blanking punches, and wear-intensive applications.
Q: Can I get pre-hardened tool steel?
Yes — some tool steel grades supplied pre-hardened (typically 28-32 HRC) so they can be machined as supplied without subsequent heat treatment. Suitable for parts that don't need maximum hardness but require some wear resistance and reliability. Pre-hardened tool steel saves heat-treatment cost and distortion. Common pre-hardened grades available through AIMS for workshop applications. Match grade to the final application requirements.
Q: How do I machine tool steel?
Annealed (soft) tool steel machines like medium-carbon steel — use HSS or carbide tools, moderate speeds and feeds, plenty of coolant. After heat treatment, hardened tool steel requires grinding (HSS won't cut — carbide marginal; diamond grinding standard). For complex tool geometry, machine in annealed state to final dimensions + 0.5mm grinding allowance, then heat-treat, then grind to final size. Allow for heat-treat distortion in tolerance calculations.
Q: Where can I get tool steel heat-treated?
Specialty heat-treatment services (typically Sydney-based for AIMS customers) handle tool steel hardening and tempering. For workshop one-off heat treatment, the heat-treatment shop matches the grade-specific process (O1 oil quench, A2 air cool, D2 high-temperature air harden). AIMS can refer to qualified heat-treatment service providers. For ongoing tool work, establish a relationship with one heat-treatment shop for consistent results.
Q: When should I specify H13 hot-work tool steel?
H13 is the workhorse hot-work tool steel for applications where the tool sees repeated exposure to elevated temperature — aluminium and zinc die casting dies, hot forging dies, extrusion dies, hot stamping and hot shear tooling. H13 combines good high-temperature strength (retains hardness at 500-600°C service temperature), excellent thermal shock resistance (survives repeated heating and cooling cycles without cracking), and reasonable machining and heat treatment characteristics. Standard hardness range after heat treatment is 42-52 HRC — softer than cold-work tool steels like D2 (58-62 HRC) but tough enough to survive the thermal and mechanical stress of hot working. For cold-work die and punch applications, prefer O1, A2, or D2 rather than H13.
Q: What are HSS tool steels used for?
HSS (high-speed steel) grades — M2, M35, M42, and specialty grades — are used for cutting tools where the tool sees high temperature at the cutting edge from cutting friction. Common grades: M2 (general HSS drill bits, taps, end mills), M35 (M2 with 5 percent cobalt for increased hot hardness), M42 (M2 with 8 percent cobalt for maximum hot hardness on stainless and superalloy cutting), and PM-HSS (powder metallurgy HSS with more even microstructure for high-performance milling and turning). HSS tool steels aren't typically machined into tooling from raw stock in a general workshop — they're bought as finished cutting tools (drills, taps, end mills) already heat-treated to full hardness. For selection detail see our cobalt drill bit guide and carbide vs HSS end mill guide.
Q: What forms are tool steels typically supplied in?
Round bar (turned or ground finish) for shaft, punch, and rotational tool work — common diameters from 6mm to 100mm in standard grades. Flat bar (hot-rolled or precision-ground) for die and blade work. Precision ground flat stock (also called "tool room stock") comes machined to close tolerance on all sides and suits direct use with minimal machining. Plate for larger die blocks — typically ground on two faces with saw cuts to size. Blanks (pre-cut round or square pieces) for hand tools and specialty tooling. Contact AIMS with the grade, dimension, length, and heat treatment condition required — availability varies by grade and section.
Q: What is the difference between hardened and annealed tool steel supply?
Annealed (soft) tool steel is supplied at 20-30 HRC — soft enough to machine with standard workshop tools (HSS or carbide, moderate speeds and feeds). After machining to finished dimension, the workpiece is sent for heat treatment (harden + temper) to reach the final working hardness of 58-64 HRC. This is the standard workflow for punches, dies, and workshop tooling. Pre-hardened tool steel (P20 mould steel is the common example at 28-32 HRC) machines directly to finished dimension without further heat treatment — suits mould plates and precision fixturing where dimensional stability matters. Full-hardness (58-64 HRC) tool steel can only be worked by grinding or EDM — too hard for turning, milling, or drilling.
Q: What heat treatment is required for common tool steels?
O1 (oil-hardening): heat to 780-810°C, quench in oil, temper to required hardness — the most forgiving grade for workshop heat treatment. A2 (air-hardening): heat to 940-980°C, still-air cool, temper — dimensional stability is the key advantage. D2 (air-hardening high-chrome): heat to 1000-1040°C, still-air cool, temper — abrasive-wear-resistant but harder to machine and less tough than O1. H13 (hot-work): heat to 1010-1040°C, still-air or oil cool, temper — usually double or triple tempered. Heat treatment requires temperature control within 10-20°C, controlled atmosphere or protective coating to prevent decarburisation, and proper tempering after quench. For workshop tools, use a qualified heat-treatment shop rather than attempting furnace work with imprecise temperature control. Cross-links: raw materials for other metal stock, Sutton Tools for Australian-made HSS cutting tools, drill bits and end mills and milling cutters for finished HSS tooling.