Stainless Steel S42300
UNS S42300
A modified martensitic stainless steel with a chromium-molybdenum-vanadium composition beyond standard 420, offering higher strength and improved toughness after heat treatment; chosen for high-performance cutlery and surgical instruments requiring a fine, strong edge.
Reference datasheet — S42300 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 QT650 condition
S42300 tempers and conditions
S42300 is supplied in 5 conditions, soft to hard. QT650 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 |
|---|---|---|---|---|---|---|
Solution annealed | Softest supply condition for rough machining, forming or re-heat-treatment by the customer. | 520 | 760 | 20 | 235 HB | — |
Normalized and tempered | Moderate-strength, high-toughness bar/forging condition for large sections and high-temperature bolting. | 700 | 900 | 18 | 26 HRC | — |
QT650Default Q&T 650 °C | Standard turbine-blade / high-temperature service condition: best balance of strength, toughness and creep stability. | 850 | 1,000 | 17 | 30 HRC | — |
Q&T 590 °C | Higher-strength condition for blades, valve stems and wear parts where service temperature stays below ~480 °C. | 1,000 | 1,170 | 14 | 36 HRC | — |
Hardened + low temper | Maximum hardness/edge-retention condition for cutlery, surgical and wear components; low toughness, avoid the 400–550 °C temper-embrittlement band. | 1,350 | 1,650 | 8 | 49 HRC | — |
What is S42300?
A modified martensitic stainless steel with a chromium-molybdenum-vanadium composition beyond standard 420, offering higher strength and improved toughness after heat treatment; chosen for high-performance cutlery and surgical instruments requiring a fine, strong edge. S42300 has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 58% of stainless steel grades. It melts at 1,425°C (2,597 °F). S42300 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 97% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 200 GPa (29 Msi).
What is S42300 used for?
- Premium knife blades
- Surgical and dental instruments
- High-end cutlery
- Wear-resistant tooling components
Advantages
- High strength — 850 MPa (123 ksi), 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
- Needs corrosion protection — 40/100, worse than 93% of stainless steel grades
- Difficult to weld — 25/100, worse than 92% of stainless steel grades
- Limited ductility — 17%, worse than 86% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Low fracture toughness — 80 MPa·√m (72.8 ksi·√in), worse than 79% of stainless steel grades
S42300 properties
Typical room-temperature values for S42300-QT650; bars are the position among stainless steel grades.
Physical3
S42300 has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 58% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
S42300 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 97% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S42300 is rated for continuous service to 540°C (1,004 °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 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
S42300 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 S42300 takes about 53 MJ of energy and emits 4.8 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 45%.
Manufacturability6
S42300's machinability is fair (38/100, better than 63% of stainless steel grades); weldability poor (25/100); formability poor (20/100).
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. S42300 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S42300
Is S42300 easy to machine?
Machine in the annealed or 28–32 HRC condition with rigid setups, sharp carbide tooling, slow speeds and generous coolant; above ~40 HRC switch to CBN/ceramic or grinding.
Can S42300 be welded?
Air-hardening: preheat 200–300 °C, use matching 12Cr-Mo-V or austenitic filler, and temper immediately after welding (~650–700 °C) to restore toughness and avoid cold cracking.
Can S42300 be formed, bent or molded?
Hot work at 1050–1180 °C with slow cooling to an anneal; cold forming is essentially limited to light bending in the annealed state.
S42300 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 |
|---|---|---|
| C | 0.27 – 0.32 | 0.3 |
| Mn | 0.95 – 1.65 | 1.1 |
| Si | ≤ 0.5 | 0.3 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 11 – 12 | 11.5 |
| Mo | 2.5 – 3 | 2.75 |
| V | 0.2 – 0.3 | 0.25 |
| Nimax, residual | ≤ 0.5 | |
| Nspecified in some turbine-blade specifications | 0.05 – 0.1 | 0.06 |
| Fe | balance |
What surface finishes work on S42300?
Takes a fine polish and holds an edge; passivate after machining and avoid chloride exposure — hard-chrome, nitriding or PVD coatings are used where wear or corrosion demands more.
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 S42300 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Alloy 619
- Similar grades
- 420 Modified
How much does S42300 cost?
S42300 is a premium-cost stainless steel ($$$), cheaper than about 51% 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.
S42300 — frequently asked
What is S42300 used for?
S42300 is typically used for premium knife blades, surgical and dental instruments, high-end cutlery and wear-resistant tooling components. In short: higher-toughness 420 upgrade; fine-edge blade steel; air-hardening Cr-Mo-V martensitic.
What is the yield strength of S42300?
S42300 has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 97% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is S42300 easy to machine?
Not especially — machinability is rated fair (38/100, better than 63% of stainless steel grades). Machine in the annealed or 28–32 HRC condition with rigid setups, sharp carbide tooling, slow speeds and generous coolant; above ~40 HRC switch to CBN/ceramic or grinding.
Can S42300 be welded?
Not readily — weldability is rated poor (25/100). Air-hardening: preheat 200–300 °C, use matching 12Cr-Mo-V or austenitic filler, and temper immediately after welding (~650–700 °C) to restore toughness and avoid cold cracking.
What surface finishes work on S42300?
Takes a fine polish and holds an edge; passivate after machining and avoid chloride exposure — hard-chrome, nitriding or PVD coatings are used where wear or corrosion demands more.
Can S42300 be formed, bent or molded?
Hot work at 1050–1180 °C with slow cooling to an anneal; cold forming is essentially limited to light bending in the annealed state.
What is the maximum service temperature of S42300?
S42300 is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S42300-QT650 and S42300-QT200?
QT650 is the default condition — standard turbine-blade / high-temperature service condition: best balance of strength, toughness and creep stability. QT200: maximum hardness/edge-retention condition for cutlery, surgical and wear components; low toughness, avoid the 400–550 °C temper-embrittlement band. Yield strength is 850 MPa in QT650 versus 1,350 MPa in QT200.
How much does S42300 cost?
S42300 is a premium-cost stainless steel ($$$), cheaper than about 51% 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
- ASTM A565/A565M — Martensitic Stainless Steel Bars for High-Temperature Service (Grade 619) — ASTM International (2019)
- SAE J1086 / ASTM DS-56 — Metals & Alloys in the Unified Numbering System (UNS S42300) — SAE/ASTM (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- Machinery's Handbook, machinability ratings for martensitic stainless — Industrial Press (2020)
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.