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Steel 33B2 +AC vs 33B2 +H

Steel · 33B2 temper comparison

33B2 +AC and 33B2 +H are two conditions of the same steel grade, 33B2: +AC (spheroidize annealed) versus +H (hardenability-controlled quality, hardened). The chemistry is identical, so every difference below comes from the condition. 33B2 +H is the stronger of the two: yield strength 1,300 MPa (189 ksi) against 320 MPa (46.4 ksi) for 33B2 +AC, about 4.1 times as much; tensile strength follows at 1,650 MPa (239 ksi) vs 510 MPa (74 ksi). In exchange, 33B2 +AC is the more ductile: elongation 24% versus 4% for 33B2 +H, and 33B2 +H is harder (480 HB vs 150 HB). 33B2 +AC runs hotter in service (400°C vs 150°C continuous). On the shop floor, 33B2 +AC machines more easily (good vs poor) and 33B2 +AC welds better (fair vs poor).

33B2 +ACChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

33B2 +HChoose it when strength drives the design.

33B2 +AC vs 33B2 +H: properties

33B2 +AC33B2 +H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

510 MPa74 ksi
1,650 MPa239 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
1,300 MPa189 ksi

Elongation at Break

24%
4%

Reduction in Area

63%
20%

Shear Strength

320 MPa46.4 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
290 MPa42.1 ksi

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

150 HB
480 HB

Hardness, Rockwell B

80 HRB
89 HRB

Hardness, Vickers

158 HV
520 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 · Compressive Strength 520 MPa75.4 ksi

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)

400°C752 °F
150°C302 °F

Same in both: Thermal Conductivity 46 W/m·K26.6 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.1 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

60 / 100
20 / 100

Machinability Rating (AISI 1212 = 100 %)

68%
20%

Weldability

45 / 100
20 / 100

Formability (cold)

90 / 100
5 / 100

Same in both: Brazeability / Solderability 60 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 40 L/kg4.8 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 scale33B2

33B2 +AC vs 33B2 +H — frequently asked

Is 33B2 +H stronger than 33B2 +AC?

Yes. 33B2 +H has a typical yield strength of 1,300 MPa (189 ksi) against 320 MPa (46.4 ksi) for 33B2 +AC — about 4.1 times as much. Tensile strength is 1,650 MPa (239 ksi) vs 510 MPa (74 ksi).

Which condition does FabDigit quote by default, +AC or +H?

+AC+C is the default 33B2 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, 33B2 +AC or 33B2 +H?

33B2 +AC. Its machinability rates good (60/100) against poor (20/100) for 33B2 +H; for welding the order is 33B2 +AC first (fair, 45/100) then 33B2 +H (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 33B2 +AC and 33B2 +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.