Stainless Steel ATS-34
ATS-34 is a Hitachi-produced Japanese martensitic stainless steel of the 440C type (UNS S44004), chromium-molybdenum alloyed and comparable to 154CM.
Reference datasheet — ATS-34 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
ATS-34 tempers and conditions
ATS-34 is supplied in 5 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize annealed bar/plate/strip (mill supply condition) | Order in the spheroidize annealed mill condition (220 HB, 760 MPa) for blade blanks and machining, then harden and temper after cutting to reach final service hardness. | 450 | 760 | 15 | 220 HB | — |
austenitize ~1040–1060 °C, oil/plate quench, temper ~300–350 °C | Choose for large blades, chopping tools and structural parts needing higher chipping resistance; the ~300-350 °C temper trades some edge retention for toughness. | 1,650 | 1,850 | 3 | 56 HRC | — |
Q&T secondary-hardened 58–59 HRC | Specify for tooling and valve parts working at 150-400 °C; the twice-repeated 510-540 °C secondary-hardening temper gives high temper stability with slightly lower corrosion resistance. | 1,800 | 1,950 | 2 | 59 HRC | 2.7 % IACS |
austenitize ~1050–1070 °C, quench, temper ~180–220 °C | Pick as the default blade heat treatment: austenitizing near 1050-1070 °C with a ~180-220 °C temper gives the best balance of hardness, edge retention and toughness. | 1,850 | 2,000 | 2 | 59 HRC | — |
Q&T + cryogenic 60–62 HRC | Use when maximum hardness and edge holding are the goal: the -75 to -196 °C sub-zero step transforms retained austenite, at the cost of toughness and machinability. | 1,950 | 2,100 | 1.5 | 61 HRC | — |
What is ATS-34?
ATS-34 is a Hitachi-produced Japanese martensitic stainless steel of the 440C type (UNS S44004), chromium-molybdenum alloyed and comparable to 154CM. Its fine grain structure and strong hardenability let it reach 60-62 HRC with a cryogenic cycle, and it is supplied as annealed strip and flat bar for blade blanks and small hardened components. Annealed properties are 450 MPa yield, 760 MPa tensile and 15 % elongation at 220 HB; machinability rates 35, weldability 20, formability 25 and corrosion resistance 40, with service limited to 400 °C. 154CM is the direct substitute. ATS-34 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 57% of stainless steel grades. It melts at 1,370°C (2,498 °F). ATS-34 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 70% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 200 GPa (29 Msi).
What is ATS-34 used for?
- Premium knife blades
- Kitchen cutlery
- Folding knife blades
- Custom and semi-custom blade blanks
- Hardened wear inserts and edges
- Hunting and outdoor knives
Advantages
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Difficult to weld — 20/100, worse than 95% of stainless steel grades
- Needs corrosion protection — 40/100, worse than 93% of stainless steel grades
- Limited ductility — 15%, worse than 89% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
ATS-34 properties
Typical room-temperature values for ATS-34-Annealed; bars are the position among stainless steel grades.
Physical3
ATS-34 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 57% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical12
ATS-34 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 70% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
ATS-34 is rated for continuous service to 400°C (752 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 10.2 µm/m·K (5.67 µin/in·°F).
Electrical3
ATS-34 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 93% of stainless steel grades.
Sustainability4
Producing a kilogram of ATS-34 takes about 55 MJ of energy and emits 5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 25%.
Manufacturability8
ATS-34's machinability is fair (35/100, better than 51% of stainless steel grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. ATS-34 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ATS-34
Is ATS-34 easy to machine?
Machine only in the annealed condition: low speed, heavy feed, rigid clamping and coated carbide or powder high-speed steel tooling. Once hardened, use grinding or EDM only.
Can ATS-34 be welded?
Fusion welding is not recommended, as high-carbon martensite cold-cracks readily. If unavoidable, preheat 200-300 °C and temper immediately after welding, or switch to brazing or mechanical joining.
Can ATS-34 be formed, bent or molded?
Cold formability is very poor. Forge in the range 1100 °C down to 900 °C, then cool slowly and spheroidize anneal to prevent cracking.
ATS-34 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Chigh carbon for M7C3/M6C carbides | 1 – 1.1 | 1.05 |
| Cr | 13 – 14.5 | 14 |
| Mowear resistance + pitting resistance | 3.75 – 4.25 | 4 |
| Mn | ≤ 0.5 | 0.4 |
| Si | ≤ 0.5 | 0.35 |
| Pimpurity | ≤ 0.03 | |
| Simpurity | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on ATS-34?
The fine grain structure polishes to a mirror. Passivate after heat treatment to restore the passive film; DLC/PVD and satin brushed finishes are options, and anodizing does not apply.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel ATS-34 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- S44004
How much does ATS-34 cost?
ATS-34 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ATS-34 — frequently asked
What is ATS-34 used for?
ATS-34 is typically used for premium knife blades, kitchen cutlery, folding knife blades, custom and semi-custom blade blanks, hardened wear inserts and edges and hunting and outdoor knives. In short: fine-grained 154CM analogue; strong hardenability, 62 HRC; not for welded assemblies.
What is the yield strength of ATS-34?
ATS-34 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 70% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is ATS-34 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine only in the annealed condition: low speed, heavy feed, rigid clamping and coated carbide or powder high-speed steel tooling. Once hardened, use grinding or EDM only.
Can ATS-34 be welded?
Not readily — weldability is rated poor (20/100). Fusion welding is not recommended, as high-carbon martensite cold-cracks readily. If unavoidable, preheat 200-300 °C and temper immediately after welding, or switch to brazing or mechanical joining.
What surface finishes work on ATS-34?
The fine grain structure polishes to a mirror. Passivate after heat treatment to restore the passive film; DLC/PVD and satin brushed finishes are options, and anodizing does not apply.
Can ATS-34 be formed, bent or molded?
Cold formability is very poor. Forge in the range 1100 °C down to 900 °C, then cool slowly and spheroidize anneal to prevent cracking.
What is the maximum service temperature of ATS-34?
ATS-34 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does ATS-34 cost?
ATS-34 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ATS-34 martensitic stainless knife steel data — Hitachi Metals (Proterial) (2019)
- 154CM / CPM 154 datasheet — Crucible Industries (2018)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASTM A276 / UNS S44004 (440C) related martensitic stainless requirements — ASTM (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.