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Steel 100Cr6-HR vs 100Cr6 Q&T

Steel · 100Cr6 temper comparison

100Cr6-HR and 100Cr6 Q&T are two conditions of the same steel grade, 100Cr6: HR (hot rolled) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 100Cr6 Q&T is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 550 MPa (79.8 ksi) for 100Cr6-HR, about 3.5 times as much; tensile strength follows at 2,240 MPa (325 ksi) vs 950 MPa (138 ksi). In exchange, 100Cr6-HR is the more ductile: elongation 10% versus 1% for 100Cr6 Q&T, and 100Cr6-HR is harder (280 HB vs 200 HB). 100Cr6-HR runs hotter in service (200°C vs 150°C continuous) and 100Cr6-HR conducts heat better (44 W/m·K vs 34 W/m·K). On the shop floor, 100Cr6-HR machines more easily (poor vs not recommended).

100Cr6-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

100Cr6 Q&TChoose it when strength drives the design.

100Cr6-HR vs 100Cr6 Q&T: properties

100Cr6-HR100Cr6 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

950 MPa138 ksi
2,240 MPa325 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
1,900 MPa276 ksi

Elongation at Break

10%
1%

Reduction in Area

30%
3%

Shear Strength

570 MPa82.7 ksi
1,300 MPa189 ksi

Fatigue Strength (Endurance Limit)

420 MPa60.9 ksi
750 MPa109 ksi

Charpy V-Notch Impact (RT)

10 J7.4 ft·lbf
5 J3.7 ft·lbf

Hardness, Brinell

280 HB
200 HB

Hardness, Vickers

295 HV
770 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 94 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.81 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,424°C2,595 °F · Liquidus Temperature 1,455°C2,651 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
34 W/m·K19.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
150°C302 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

28 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
5%

Weldability

10 / 100
5 / 100

Formability (cold)

15 / 100
2 / 100

Polishability

88 / 100
92 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 65 L/kg7.8 gal/lb · Typical Recycled Content 30%

Strength versus weight

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

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale100Cr6

100Cr6-HR vs 100Cr6 Q&T — frequently asked

Is 100Cr6 Q&T stronger than 100Cr6-HR?

Yes. 100Cr6 Q&T has a typical yield strength of 1,900 MPa (276 ksi) against 550 MPa (79.8 ksi) for 100Cr6-HR — about 3.5 times as much. Tensile strength is 2,240 MPa (325 ksi) vs 950 MPa (138 ksi).

Which condition does FabDigit quote by default, HR or Q&T?

Annealed is the default 100Cr6 condition in the FabDigit quote flow (neither HR nor Q&T). 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, 100Cr6-HR or 100Cr6 Q&T?

100Cr6-HR. Its machinability rates poor (28/100) against not recommended (10/100) for 100Cr6 Q&T; for welding the order is 100Cr6-HR first (not recommended, 10/100) then 100Cr6 Q&T (not recommended, 5/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 100Cr6-HR and 100Cr6 Q&T 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.