Stainless Steel S42010 Q&T 28-34 HRC
Hardness band
UNS S42010
Q&T 28-34 HRC = hardened and high-temperature tempered
Choose for shafts and structural parts needing toughness and moderate strength rather than wear resistance.
Values for the Q&T 28-34 HRC condition
Other S42010 tempers and conditions
S42010 is listed in 6 conditions; see the grade overview at S42010.
- Annealed
- CD
- Q&T 28-34 HRC
- Q&T 38-44 HRC
- Q&T 48-52 HRC
- Q&T 52-56 HRC
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault Annealed (soft annealed / mill annealed bar) | Standard stocked condition for machining and forming before customer hardening. | 450 | 760 | 20 | 20 HRC | — |
Cold drawn | Pick for straight, close-tolerance bar with higher as-supplied strength for parts finished without hardening. | 690 | 860 | 13 | 26 HRC | — |
Q&T 28-34 HRCThis page Hardened and high-temperature tempered | Choose for shafts and structural parts needing toughness and moderate strength rather than wear resistance. | 800 | 1,000 | 15 | 31 HRC | — |
Hardened and tempered ~450–540 °C | Compromise hardness for valve stems and pump parts; avoid long holds in the 475 °C embrittlement range. | 1,100 | 1,350 | 11 | 41 HRC | — |
Hardened ~1030–1065 °C, tempered 200–300 °C | Standard service condition for wear parts, valve trim and blades needing hardness plus corrosion resistance. | 1,450 | 1,720 | 7 | 50 HRC | — |
Hardened with cryogenic treat, tempered 150–200 °C | Maximum hardness condition for cutlery edges and severe abrasion; lowest toughness and most sensitive to grinding cracks. | 1,620 | 1,930 | 4 | 54 HRC | — |
What is S42010 Q&T 28-34 HRC?
S42010 Q&T 28-34 HRC is S42010 heat treated to Q&T 28-34 HRC — choose for shafts and structural parts needing toughness and moderate strength rather than wear resistance. S42010 Q&T 28-34 HRC has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 200 GPa (29 Msi). S42010 Q&T 28-34 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,454°C (2,649 °F). Annealed is the default condition FabDigit quotes; Q&T 28-34 HRC is available on request or by drawing note.
Advantages
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
- High strength — 800 MPa (116 ksi), better than 96% of stainless steel grades
- Conducts heat well — 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades
Limitations
- Needs corrosion protection — 32/100, worse than 99% of stainless steel grades
- Difficult to weld — 25/100, worse than 92% of stainless steel grades
- Limited ductility — 15%, worse than 89% of stainless steel grades
S42010 Q&T 28-34 HRC properties
Typical room-temperature values for S42010 Q&T 28-34 HRC; 13 are specific to this condition. Other listed values are S42010 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S42010 Q&T 28-34 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,454°C (2,649 °F).
Mechanical16
S42010 Q&T 28-34 HRC has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S42010 Q&T 28-34 HRC is rated for continuous service to 500°C (932 °F). It conducts heat at 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).
Electrical3
S42010 Q&T 28-34 HRC conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of S42010 Q&T 28-34 HRC takes about 53 MJ of energy and emits 4.3 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 55%.
Manufacturability8
S42010 Q&T 28-34 HRC's machinability is poor (33/100, worse than 57% of stainless steel grades); weldability poor (25/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S42010 Q&T 28-34 HRC
Is S42010 easy to machine?
Machine in the annealed condition with sharp, rigid, positive-rake carbide tooling, heavy feeds and generous coolant; above ~45 HRC switch to grinding, CBN or EDM.
Can S42010 be welded?
Air-hardening and crack-prone — preheat 200–300 °C, use 410/410NiMo filler, keep interpass hot and temper immediately after welding; welding of hardened parts is not recommended.
Can S42010 be formed, bent or molded?
Only light cold forming in the annealed state with generous bend radii; hot work at 1050–1200 °C and slow-cool or full anneal at 840–900 °C before machining.
What surface finishes work on S42010?
Passivate per ASTM A967 (nitric or citric) after machining for full corrosion resistance; takes a fine mirror polish and accepts hard chrome, PVD or black oxide, but avoid tempering/bake above 300 °C on low-tempered parts.
S42010 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 |
|---|---|---|
| Chardening carbon | 0.15 – 0.3 | 0.22 |
| Mn | ≤ 1 | 0.6 |
| Si | ≤ 1 | 0.4 |
| Pimpurity | ≤ 0.04 | — |
| Simpurity | ≤ 0.03 | — |
| Cr | 13.5 – 15 | 14.2 |
| Nitoughness / hardenability | 0.4 – 1 | 0.7 |
| Mopitting resistance and temper strength | 0.4 – 1 | 0.7 |
| Fe | balance | — |
S42010 Q&T 28-34 HRC — frequently asked
What is S42010 Q&T 28-34 HRC used for?
S42010 Q&T 28-34 HRC is typically used for surgical and dental instruments, cutlery and blades, bearings and valve parts and wear-resistant tooling. In short: harder than standard 420; mo-modified corrosion edge; four Q&T hardness bands.
What is the yield strength of S42010 Q&T 28-34 HRC?
S42010 Q&T 28-34 HRC has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 96% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is S42010 Q&T 28-34 HRC easy to machine?
Not especially — machinability is rated poor (33/100, worse than 57% of stainless steel grades). Machine in the annealed condition with sharp, rigid, positive-rake carbide tooling, heavy feeds and generous coolant; above ~45 HRC switch to grinding, CBN or EDM.
Can S42010 Q&T 28-34 HRC be welded?
Not readily — weldability is rated poor (25/100). Air-hardening and crack-prone — preheat 200–300 °C, use 410/410NiMo filler, keep interpass hot and temper immediately after welding; welding of hardened parts is not recommended.
What surface finishes work on S42010 Q&T 28-34 HRC?
Passivate per ASTM A967 (nitric or citric) after machining for full corrosion resistance; takes a fine mirror polish and accepts hard chrome, PVD or black oxide, but avoid tempering/bake above 300 °C on low-tempered parts.
Can S42010 Q&T 28-34 HRC be formed, bent or molded?
Only light cold forming in the annealed state with generous bend radii; hot work at 1050–1200 °C and slow-cool or full anneal at 840–900 °C before machining.
What is the maximum service temperature of S42010 Q&T 28-34 HRC?
S42010 Q&T 28-34 HRC is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S42010 Annealed and S42010-CD?
Annealed is the default condition — standard stocked condition for machining and forming before customer hardening. CD: pick for straight, close-tolerance bar with higher as-supplied strength for parts finished without hardening. Yield strength is 450 MPa in Annealed versus 690 MPa in CD.
Sources
- ASTM A276/A276M Stainless Steel Bars and Shapes — ASTM International (2023)
- ASTM A473 Stainless Steel Forgings — ASTM International (2020)
- SAE J1086 / UNS Numbering of Metals and Alloys — SAE International (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- Martensitic stainless bar (420 modified, Mo-bearing) technical data — Crucible / Universal Stainless (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.