Steel 17Cr3 +AC vs 17Cr3 +H
Steel · 17Cr3 temper comparison
17Cr3 +AC and 17Cr3 +H are two conditions of the same steel grade, 17Cr3: +AC (spheroidize annealed) versus +H (specified hardenability (Jominy band); blank-hardened properties). The chemistry is identical, so every difference below comes from the condition. 17Cr3 +H is the stronger of the two: yield strength 490 MPa (71.1 ksi) against 320 MPa (46.4 ksi) for 17Cr3 +AC, about 53% more; tensile strength follows at 800 MPa (116 ksi) vs 540 MPa (78.3 ksi). In exchange, 17Cr3 +AC is the more ductile: elongation 24% versus 11% for 17Cr3 +H, and 17Cr3 +H is harder (240 HB vs 155 HB). 17Cr3 +AC runs hotter in service (350°C vs 200°C continuous). On the shop floor, 17Cr3 +AC machines more easily (good vs fair) and 17Cr3 +AC welds better (good vs fair).
17Cr3 +ACChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
17Cr3 +HChoose it when strength drives the design.
17Cr3 +AC vs 17Cr3 +H: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Compressive Strength 370 MPa53.7 ksi · Shear Strength 400 MPa58 ksi · Hardness, Rockwell B 87 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.1×10⁻⁷ Ω·m8.27 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 13 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 25 / 100 · Brazeability / Solderability 65 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 50 L/kg6 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.
17Cr3 +AC vs 17Cr3 +H — frequently asked
Is 17Cr3 +H stronger than 17Cr3 +AC?
Yes. 17Cr3 +H has a typical yield strength of 490 MPa (71.1 ksi) against 320 MPa (46.4 ksi) for 17Cr3 +AC — about 53% more. Tensile strength is 800 MPa (116 ksi) vs 540 MPa (78.3 ksi).
Which condition does FabDigit quote by default, +AC or +H?
+FP is the default 17Cr3 condition in the FabDigit quote flow (neither +AC nor +H). 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, 17Cr3 +AC or 17Cr3 +H?
17Cr3 +AC. Its machinability rates good (55/100) against fair (45/100) for 17Cr3 +H; for welding the order is 17Cr3 +AC first (good, 62/100) then 17Cr3 +H (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 17Cr3 +AC and 17Cr3 +H 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.