Corona SteelIndustry Pvt Ltd
PT

Escolher idioma

Busca de produtosSolicitar orçamento
PT

Escolher idioma

Menu
Mapa do site07 entradas
Corona SteelFundada em 1955
Resources/Materials & grades/P20 / 1.2311

Materials & grades

P20 / 1.2311 / 1.2738 pre-hardened mould steel: equivalents 40CrMnMo7 and 40CrMnNiMo8-6-4

P20 is a low-alloy chromium-molybdenum mould steel supplied pre-hardened at about 28–34 HRC (280–325 HB), so plastic injection moulds and mould bases can be machined without a further hardening step. In Europe it is closest to 1.2311 (40CrMnMo7) and the nickel version 1.2738 (40CrMnNiMo8-6-4).

Names by standard

What it is called in each region

RegionSystemDesignationNormaMatch
USAAISI/SAEP20ASTM A681Same material
UNST51620—Same material
UKBS 4659BP20Superseded British standard, withdrawn. Listed against P20 and 1.2311 by West Yorkshire Steel; not confirmed in a primary source.BS 4659:1971Closest equivalent
EUEN 10027-2 number1.2311Dörrenberg: 1.2311 'similar to AISI P20'; no added sulphur or nickel. Supplied quenched and tempered, 280–325 HB.EN ISO 4957Equivalent
DIN (legacy)40CrMnMo7Superseded German name for 1.2311, still widely used.DIN 17350Equivalent
EN 10027-1 name40CrMnNiMo8-6-4Number 1.2738, the P20+Ni version. The nickel (about 1 %) improves through-hardening in sections above about 400 mm. Dörrenberg and Böhler (M238) show this name for 1.2738.EN ISO 4957Closest equivalent
EN 10027-2 number1.2738EN ISO 4957Closest equivalent
EN 10027-1 name40CrMnMoS8-6 (1.2312)Free-machining P20+S version with about 0.08 % sulphur (Böhler M200).EN ISO 4957Closest equivalent
ÍndiaIS 3748:2022 (ISO 4957 name)40CrMnNiMo8-6-4IS 3748:2022 is an identical adoption of ISO 4957. An earlier Indian IS designation for P20 was not found.IS 3748:2022Closest equivalent
JapanMaker's grade (Daido Steel)PX5 / PXA30No direct JIS G 4404 grade matches P20. Daido classes PX5 and PX4 as modified P20 and supplies them pre-hardened at about 32 HRC (Daido SD2311).—Closest equivalent

On equivalence

  • P20 is a family. ASTM A681 P20 has 0.28–0.40 % C, 0.60–1.00 % Mn, 1.40–2.00 % Cr and 0.30–0.55 % Mo. The European 1.2311 / 1.2738 steels have more manganese (about 1.5 %), a little more chromium (about 1.9 %) and less molybdenum (about 0.2 %).
  • Dörrenberg states that EN ISO 4957 merged 1.2311 (P20), 1.2312 (P20+S) and 1.2738 (P20+Ni) into one code, 40CrMnNiMo8-6-4. 1.2311 has no added sulphur or nickel; 1.2738 has about 1 % nickel; 1.2312 has about 0.08 % sulphur.
  • Typical analyses: Dörrenberg 1.2311 is 0.40 % C, 1.50 % Mn, 1.90 % Cr and 0.20 % Mo; 1.2738 adds 1.00 % Ni; Böhler M238 is 0.38 % C, 0.3 % Si, 1.5 % Mn, 2.0 % Cr, 0.2 % Mo and 1.1 % Ni.
  • Common US mill brands sold as modified P20 (for example Swiss Steel P-20 Modified: 0.34 % C, 0.8 % Mn, 1.75 % Cr, 0.4 % Mo, 0.4 % Si) sit inside the ASTM A681 ranges.
  • No JIS G 4404 grade matches P20. Daido sells PX5 and PX4 as modified P20 (pre-hardened about 32 HRC) and West Yorkshire Steel's cross-reference table shows no JIS entry for P20.
  • The EU composition shown here is for 40CrMnNiMo8-6-4 (the nickel grade). For the nickel-free 1.2311 use the Dörrenberg typical analysis above and check the supplier's certificate.

Chemical composition

Composition limits, mass %

ElementP20 (T51620)USA · ASTM A68140CrMnNiMo8-6-4 (1.2738)EU · EN ISO 495740CrMnNiMo8-6-4Índia · IS 3748:2022 (identical to ISO 4957)
C0.28–0.400.35–0.450.35–0.45
Si0.20–0.800.20–0.400.20–0.40
Mn0.60–1.001.30–1.601.30–1.60
P≤0.030——
S≤0.030——
Cr1.40–2.001.80–2.101.80–2.10
Ni—0.90–1.200.90–1.20
Mo0.30–0.550.15–0.250.15–0.25

Mechanical properties

Strength and hardness

ConditionTensile strengthYield strengthElongationHardness
Quenched and tempered (pre-hardened delivery), 1.2311 and 1.2738Delivery condition, corresponds to about 950–1100 MPa by ISO 18265 conversionDörrenberg 1.2311 and 1.2738 data sheets950–1100 MPa138–160 ksi——280–325 HB (about 28–34 HRC)
Quenched and tempered (pre-hardened delivery), Böhler M238 and Uddeholm Impax SupremeDelivery condition for 1.2738 typeBöhler M238 and Uddeholm Impax Supreme data sheets; Böhler M200 (1.2312) also 290–330 HB———290–330 HB
Quenched and tempered, modified P20 (Swiss Steel)Typical supplied hardness 293–321 HB (30–34 HRC), typical strength valuesSwiss Steel P-20 Modified technical datasheet (reduction of area 35 %)1034 MPa150 ksi896 MPa130 ksi15 %293–321 HB (30–34 HRC)
Soft annealedMaximumDörrenberg 1.2311 and 1.2738 data sheets———≤235 HB
Hardened and tempered at 370 °C (700 °F)Approximate, after 2 h at temperature, P-20 ModifiedSwiss Steel P-20 Modified technical datasheet———51 HRC
Hardened and tempered at 425 °C (800 °F)Approximate, after 2 h at temperatureSwiss Steel P-20 Modified technical datasheet———50 HRC
Hardened and tempered at 480 °C (900 °F)Approximate, after 2 h at temperatureSwiss Steel P-20 Modified technical datasheet———47 HRC
Hardened and tempered at 540 °C (1000 °F)Approximate, after 2 h at temperatureSwiss Steel P-20 Modified technical datasheet———43 HRC
Hardened and tempered at 595 °C (1100 °F)Approximate, after 2 h at temperatureSwiss Steel P-20 Modified technical datasheet———35 HRC
Hardened and tempered at 620 °C (1150 °F)Approximate, after 2 h at temperatureSwiss Steel P-20 Modified technical datasheet———33 HRC

In practice

Behaviour, heat treatment and uses

Characteristics

  • Supplied quenched and tempered, so moulds can be machined and used without further hardening (Dörrenberg, Böhler M200 and M238 'no heat treatment necessary').
  • Good machinability and polishability; the nickel version 1.2738 adds uniform strength across large sections up to about 600 mm (Böhler M238) and better polishability than the sulphur grade 1.2312 (Dörrenberg).
  • Thermal conductivity about 33–40 W/(m·K) at room temperature, much higher than a 5 % chromium hot-work steel (Böhler, Dörrenberg).
  • Not a hot-work steel. Do not stress relieve pre-hardened material above 550 °C (Böhler).
  • Weldable with preheating; Swiss Steel gives a preheat of 900–1000 °F (480–540 °C) and a post-weld retemper.
  • Hardness can be raised for wear by re-hardening or by nitriding or case hardening (Smiths Metal).
  • Not corrosion resistant (Böhler).

Heat treatment

  • Delivery: quenched and tempered to 280–325 HB (Dörrenberg) or 290–330 HB (Böhler, Uddeholm). No further heat treatment is needed for most moulds.
  • Soft annealing (if re-hardening): 710–740 °C (1310–1365 °F), furnace cooled, to ≤235 HB (Dörrenberg).
  • Stress relieving pre-hardened material: 500–550 °C (930–1020 °F), held at least 2 hours (Dörrenberg, Böhler). Do not exceed 550 °C.
  • Hardening (if needed): 830–870 °C (1525–1600 °F) for 1.2311, 840–870 °C for 1.2738, quenched in oil or a hot bath at 180–220 °C (Dörrenberg). Uddeholm Impax Supreme austenitizes at 850 °C and air cools to about 50 HRC.
  • Tempering after re-hardening: choose the temperature from the hardness required. P-20 Modified drops from 51 HRC at 700 °F (370 °C) to 33 HRC at 1150 °F (620 °C), per the Swiss Steel table; hold 1 hour per inch of thickness.

Usos típicos

  • Plastic injection moulds and compression moulds
  • Mould frames, bolsters and die holders
  • Large mould bases highly stressed in the core (1.2738)
  • Zinc die-casting dies for short runs (Smiths Metal)
  • Hydroforming tools and general tooling

Tool steels

Similar grades compared

GrauC %Mn %Cr %Ni %Tensile, first listed condition
P20 / 1.23110.28–0.400.60–1.001.40–2.000.90–1.20950–1100 MPa
A2 / 1.23630.95–1.050.40–1.004.75–5.50——
D2 / 1.23791.40–1.600.10–0.6011.00–13.00——
D3 / 1.20802.00–2.350.10–0.6011.00–13.50——
O1 / 1.25100.85–1.001.00–1.400.40–0.70——
S70.45–0.550.20–0.903.00–3.50——
H11 / 1.23430.33–0.430.20–0.504.75–5.50—1790–1845 MPa
H13 / 1.23440.32–0.450.20–0.604.75–5.50—1730–1845 MPa
M2 / HS6-5-2C0.78–0.880.15–0.403.75–4.50—≤950 MPa
M42 / HS2-9-1-81.05–1.150.15–0.403.50–4.25—≤1010 MPa

Composition from the US standard where one exists, otherwise the first standard listed on each grade's page. Strength conditions differ between grades; open a grade for its full table.

Perguntas respondidas

Common questions

What is the equivalent of P20 steel?

The closest European steels are 1.2311 (40CrMnMo7) and 1.2738 (40CrMnNiMo8-6-4, P20+Ni). Under EN ISO 4957 and, since IS 3748:2022, in India the family is covered by the name 40CrMnNiMo8-6-4. Japan has no JIS grade for it.

Is 1.2311 the same as P20?

1.2311 is the European steel that Dörrenberg and others call similar to AISI P20, but the analyses differ: 1.2311 has about 1.5 % manganese and 0.2 % molybdenum, while ASTM A681 P20 has 0.60–1.00 % manganese and 0.30–0.55 % molybdenum.

What is the difference between 1.2311, 1.2312 and 1.2738?

1.2311 is the base grade. 1.2312 adds sulphur for machinability. 1.2738 adds about 1 % nickel for through-hardening of large sections. All three are normally supplied at 280–325 HB.

What hardness is P20 supplied at?

About 280–325 HB, roughly 28–34 HRC, in the quenched and tempered condition. Böhler and Uddeholm quote 290–330 HB for their 1.2738 grades.

Can P20 be hardened further?

Yes. Heat to 830–870 °C and quench in oil or a hot bath, then temper to the hardness required; P-20 Modified reaches about 51 HRC after a 370 °C temper. Most users keep it pre-hardened and add nitriding or coating for wear.

From the Corona catalog

Need a part made to this specification?

Send the drawing, the material or grade, the finish, the quantity and the delivery country. The team reviews the requirement and the manufacturing route.

Iniciar uma consulta

Keep reading

H13 / 1.2344H13 is the standard 5 % chromium hot-work tool steel, used for die-casting dies, forging dies and extrusion tooling that see repeated heating and cooling.4140 / 42CrMo4AISI 4140 is a medium-carbon chromium-molybdenum alloy steel, normally used hardened and tempered for shafts, gears and high-strength bolts.A2 / 1.2363A2 is an air-hardening 5 % chromium cold-work tool steel with about 1 % carbon, hardened to about 57–63 HRC for punches, dies and gauges that need good dimensional stability.S7S7 is an air-hardening shock-resisting tool steel with about 0.5 % carbon, 3.25 % chromium and 1.4 % molybdenum that keeps high toughness at about 55–60 HRC, used for chisels, punches, heading dies and shear blades.Quenching and temperingQuenching and tempering hardens steel by cooling it rapidly from the austenite range to form martensite, then reheats it below Ac1 to trade some hardness for toughness.AnnealingAnnealing heats steel to a set temperature, holds it and cools it slowly to make it softer, more ductile and easier to machine or cold form.EN 10027 names and numbersEuropean steels carry two identifiers under EN 10027: a steel name (Part 1) such as S235JR, C45 or 42CrMo4 that describes the steel's use or chemistry, and a material number (Part 2) such as 1.0503 or 1.7225.IS 1570 and Indian designationsIndian steel names follow the letter-symbol code in IS 1762 (Part 1), which the IS 1570 schedules use: 45C8 means about 0.45% carbon, C for carbon steel and about 0.8% manganese, while alloy names such as 40Cr4Mo3 list each element with a multiplied content figure.JIS steel designationsJapanese JIS steel symbols start with S for steel and add letters for the steel family or its use, but the number means different things in different standards.SAE / AISI numbersA four-digit SAE/AISI number such as 1045 or 4140 names a carbon or alloy steel by its chemistry: the first two digits identify the steel family and the last two give the nominal carbon content in hundredths of a percent.

References

Sources

  1. Dörrenberg 1.2311 40CrMnNiMo8-6-4 (MCM) data sheet — Typical analysis, quenched and tempered 280–325 HB, soft anneal, stress relief and hardening; note on EN ISO 4957 amalgamation of 1.2311, 1.2312 and 1.2738.
  2. Dörrenberg 1.2738 40CrMnNiMo8-6-4 (MCMN) data sheet — Typical analysis with Ni, delivery 280–325 HB, hardening 840–870 °C.
  3. Böhler M238 (1.2738) data sheet — EN ISO 4957 40CrMnNiMo8-6-4, typical analysis, 290–330 HB, stress-relief limit 550 °C.
  4. Böhler M200 (1.2312, ~P20) data sheet — 40CrMnMoS8-6 (1.2312) listed as ~P20 AISI; 290–330 HB.
  5. Uddeholm Impax Supreme data sheet — W.-Nr. 1.2738, typical analysis, delivered 290–330 HB, austenitizing 850 °C.
  6. Swiss Steel: P-20 Modified technical datasheet — Typical analysis, 293–321 HB supply hardness, tempering table, typical strength, welding.
  7. Daido Steel: plastic mold steel physical properties (SD2311) — PXA30 / PX5 / PX4 pre-hardened at 32 HRC.
  8. Daido Steel: plastic mold steel range — PX4 and PX5 listed as type P20 modified, no JIS grade, AISI P20 mod., W.Nr 1.2330 mod., pre-hardened 30 HRC.
  9. eFunda: AISI P20 tool steel — A681 P20 limits: C 0.28–0.40, Mn 0.60–1.00, Si 0.20–0.80, Cr 1.40–2.00, Mo 0.30–0.55.
  10. Abrams Industries: Premium 1.2738 — 40CrMnNiMo8-6-4 limits including P and S ≤0.03; delivery max 325 HB.
  11. Marks GmbH: 1.2738 material sheet — EN ISO 4957 40CrMnNiMo8-6-4 analysis limits; delivered 290–330 HB.
  12. steelnumber: 40CrMnNiMo8-6-4 / 1.2738 — EN ISO 4957 limits including P and S ≤0.03.
  13. Total Materia: EN 1.2738 (EN ISO 4957:2018) — Edition EN ISO 4957:2018; C 0.35–0.45, Cr 1.80–2.10, Mn 1.30–1.60 visible; equivalents list 40CrMnNiMo8-6-4 (IS and ISO) and A 681 Type P20.
  14. ISO 4957:2018 Tool steels (preview) — Clause 6.2.2 names 40CrMnNiMo8-6-4 (Table 4) as delivered not annealed; no other pre-hardened mould grade named.
  15. Smiths Metal Centres: P20 (T51620) product datasheet — ASTM A681 style composition limits and typical hardness.
  16. West Yorkshire Steel: tool steel international standards table — Cross-reference row for BP20, P20, 1.2311 (40CrMnMo7); no JIS entry.
  17. Bureau of Indian Standards: IS 3748:2022 Tool Steels (standard of the week) — IS 3748:2022 is an identical adoption of ISO 4957 and merges IS 3748:1990 and IS 7291:1980.
  18. ASTM A681 Standard Specification for Tool Steels Alloy — Governing US standard for P20 (UNS T51620); limits verified against eFunda; the standard text itself was not read.
  19. EN ISO 4957:2018 Tool steels — Governing European and international standard for 40CrMnNiMo8-6-4; limits verified against Abrams, Marks and steelnumber listings. The ISO 4957:2018 preview (clause 6.2.2) names only 40CrMnNiMo8-6-4 among pre-hardened mould steels, consistent with Dörrenberg's statement of the merger; Table 4 itself was not visible.

Values summarize published limits and typical data. The governing standard and the current edition control; check them before specifying.