1.3343 equivalent grades: ASTM, EN, JIS, GB, DIN
1.3343 is high-speed steel, tungsten-molybdenum specified in EN ISO 4957. Below, the grades that can replace it — 5 standard systems in all — with the deciding limit named for each one rather than left to be looked up. The full 1.3343 data sheet carries the composition and mechanical tables.
Last updated
1.3343 and M2, W6Mo5Cr4V2, R6M5 and 1 more are the same steel under different national numbers; a single mill certificate covers both. 1.3243, 1.3344 sit one step away, differ in a strength minimum or in the quality class rather than in the metallurgy. 1.3355, 1.2379 serve the same purpose without being the same steel, so a substitution there needs the design re-checked rather than the certificate. Across systems that is 1 in AISI / SAE, 1 in GB/T (China), 1 in GOST (Russia/CIS), 1 in JIS (Japan), 4 in EN (European).
Cross-reference table
| Grade | System | Match | Why / differences |
|---|---|---|---|
| M2 | AISI / SAE | Identical | AISI M2 (UNS T11302, ASTM A600): C 0.78–1.05, W 5.50–6.75, Mo 4.50–5.50, Cr 3.75–4.50, V 1.75–2.20. The same steel. Because the ASTM carbon range covers both the plain and the high-carbon European versions, an M2 certificate should be read for its carbon level before it is matched to 1.3343 or to 1.3339. |
| W6Mo5Cr4V2 | GB/T (China) | Identical | GB/T 9943 W6Mo5Cr4V2 is the direct transcription and the most widely produced high-speed steel in China. W6Mo5Cr4V2Al adds aluminium for higher hot hardness. |
| R6M5 | GOST (Russia/CIS) | Identical | GOST 19265 R6M5: C 0.82–0.90, W 5.50–6.50, Mo 4.80–5.30, Cr 3.80–4.40, V 1.70–2.10. R6M5K5 is the 5 % cobalt version corresponding to M35. |
| SKH51 | JIS (Japan) | Identical | JIS G4403 SKH51: C 0.80–0.88, W 5.90–6.70, Mo 4.70–5.20, Cr 3.80–4.50, V 1.70–2.10 — the plain-carbon version, so about 1 HRC below HS6-5-2C at the same temper. |
| 1.3243 | EN (European) | Near | HS6-5-2-5 (M35): the same steel with 4.5–5.0 % cobalt. Cobalt raises hot hardness by about 50 °C and is the standard upgrade for stainless and high-temperature alloy machining; slightly more brittle and more expensive. |
| 1.3344 | EN (European) | Near | HS6-5-3 (M3:2): vanadium raised to 2.7–3.2 % and carbon to 1.15–1.25 %. Markedly better abrasive wear resistance for form tools and gear hobs, harder to grind. |
| 1.3355 | EN (European) | Functional | HS18-0-1 (T1): the original 18 % tungsten high-speed steel. Equivalent performance for general turning, but tungsten is heavier and dearer than molybdenum, so T1 has been displaced almost everywhere by M2. |
| 1.2379 | EN (European) | Functional | X153CrMoV12 (D2): comparable room-temperature hardness and abrasive wear resistance at a fraction of the cost, but it is soft by 300 °C. The right choice for cold blanking and the wrong one for any tool that cuts at speed. |
Identical, near and functional are defined once on the grade index; the reason column below says which limit differs in each case.
1.3343 in AISI / SAE
- M2 — Identical AISI M2 (UNS T11302, ASTM A600): C 0.78–1.05, W 5.50–6.75, Mo 4.50–5.50, Cr 3.75–4.50, V 1.75–2.20. The same steel. Because the ASTM carbon range covers both the plain and the high-carbon European versions, an M2 certificate should be read for its carbon level before it is matched to 1.3343 or to 1.3339.
1.3343 in GB/T (China)
- W6Mo5Cr4V2 — Identical GB/T 9943 W6Mo5Cr4V2 is the direct transcription and the most widely produced high-speed steel in China. W6Mo5Cr4V2Al adds aluminium for higher hot hardness.
1.3343 in GOST (Russia/CIS)
- R6M5 — Identical GOST 19265 R6M5: C 0.82–0.90, W 5.50–6.50, Mo 4.80–5.30, Cr 3.80–4.40, V 1.70–2.10. R6M5K5 is the 5 % cobalt version corresponding to M35.
1.3343 in JIS (Japan)
- SKH51 — Identical JIS G4403 SKH51: C 0.80–0.88, W 5.90–6.70, Mo 4.70–5.20, Cr 3.80–4.50, V 1.70–2.10 — the plain-carbon version, so about 1 HRC below HS6-5-2C at the same temper.
1.3343 in EN (European)
- 1.3243 — Near HS6-5-2-5 (M35): the same steel with 4.5–5.0 % cobalt. Cobalt raises hot hardness by about 50 °C and is the standard upgrade for stainless and high-temperature alloy machining; slightly more brittle and more expensive.
- 1.3344 — Near HS6-5-3 (M3:2): vanadium raised to 2.7–3.2 % and carbon to 1.15–1.25 %. Markedly better abrasive wear resistance for form tools and gear hobs, harder to grind.
- 1.3355 — Functional HS18-0-1 (T1): the original 18 % tungsten high-speed steel. Equivalent performance for general turning, but tungsten is heavier and dearer than molybdenum, so T1 has been displaced almost everywhere by M2.
- 1.2379 — Functional X153CrMoV12 (D2): comparable room-temperature hardness and abrasive wear resistance at a fraction of the cost, but it is soft by 300 °C. The right choice for cold blanking and the wrong one for any tool that cuts at speed.
Superseded names for 1.3343
- S 6-5-2 — DIN 17350 (withdrawn): The German short designation; same number 1.3343. The letters give the alloy content in order — 6 % W, 5 % Mo, 2 % V.
- BM2 — BS 4659 (withdrawn): The British designation.
- Z85WDCV — NF A 35-590: The French designation of the same steel.
- S600 / HS6-5-2 — Böhler / trade names: Böhler S600, Erasteel EM2, Thyrapid 3343. Powder-metallurgy equivalents (ASP 2023, Böhler S390 class) are different steels, not versions of this one.
Key data for 1.3343
Full composition, mechanical properties by thickness, heat treatment and applications for 1.3343 →
Verified against EN ISO 4957:2018. Last checked: October 2026.