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Stainless Steel 420C-H vs 420C QT 45-50 HRC

Stainless Steel · 420C temper comparison

420C-H and 420C QT 45-50 HRC are two conditions of the same stainless steel grade, 420C: H (hardened) versus QT 45-50 HRC. The chemistry is identical, so every difference below comes from the condition. 420C-H is the stronger of the two: yield strength 1,600 MPa (232 ksi) against 1,300 MPa (189 ksi) for 420C QT 45-50 HRC, about 23% more; tensile strength follows at 1,950 MPa (283 ksi) vs 1,550 MPa (225 ksi). In exchange, 420C QT 45-50 HRC is the more ductile: elongation 6% versus 1% for 420C-H, and 420C-H is harder (615 HB vs 220 HB). 420C QT 45-50 HRC runs hotter in service (400°C vs 200°C continuous) and 420C QT 45-50 HRC conducts heat better (30 W/m·K vs 24 W/m·K). On the shop floor, 420C QT 45-50 HRC machines more easily (poor vs not recommended) and 420C QT 45-50 HRC welds better (poor vs not recommended).

420C-HChoose it when strength drives the design.

420C QT 45-50 HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

420C-H vs 420C QT 45-50 HRC: properties

420C-H420C QT 45-50 HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,950 MPa283 ksi
1,550 MPa225 ksi

Yield Strength (0.2% offset)

1,600 MPa232 ksi
1,300 MPa189 ksi

Elongation at Break

1%
6%

Reduction in Area

2%
40%

Compressive Strength

2,000 MPa290 ksi
470 MPa68.2 ksi

Shear Strength

1,150 MPa167 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

750 MPa109 ksi
620 MPa89.9 ksi

Fracture Toughness (K_IC)

15 MPa·√m13.7 ksi·√in
28 MPa·√m25.5 ksi·√in

Charpy V-Notch Impact (RT)

5 J3.7 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

615 HB
220 HB

Hardness, Rockwell C

57 HRC
48 HRC

Hardness, Vickers

660 HV
490 HV

Same in both: Elastic (Young's) Modulus 215 GPa31.2 Msi · Shear Modulus 83 GPa12 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Hardness, Rockwell B 97 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

24 W/m·K13.9 BTU/hr·ft·°F
30 W/m·K17.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.5 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.5 % IACS
3.1 % IACS

Electrical Resistivity

7×10⁻⁷ Ω·m27.6 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.35 V · Corrosion Resistance 50 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

8 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

8%
45%

Weldability

5 / 100
20 / 100

Formability (cold)

0 / 100
5 / 100

Same in both: Castability 40 / 100 · Brazeability / Solderability 45 / 100 · Polishability 78 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 50 MJ/kg21,496 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 45%

Strength versus weight

Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scale420C

420C-H vs 420C QT 45-50 HRC — frequently asked

Is 420C-H stronger than 420C QT 45-50 HRC?

Yes. 420C-H has a typical yield strength of 1,600 MPa (232 ksi) against 1,300 MPa (189 ksi) for 420C QT 45-50 HRC — about 23% more. Tensile strength is 1,950 MPa (283 ksi) vs 1,550 MPa (225 ksi).

Which condition does FabDigit quote by default, H or QT 45-50 HRC?

+A is the default 420C condition in the FabDigit quote flow (neither H nor QT 45-50 HRC). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, 420C-H or 420C QT 45-50 HRC?

420C QT 45-50 HRC. Its machinability rates poor (22/100) against not recommended (8/100) for 420C-H; for welding the order is 420C QT 45-50 HRC first (poor, 20/100) then 420C-H (not recommended, 5/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 420C-H and 420C QT 45-50 HRC side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.