Steel M33-ANN vs M33 HT63-65
Steel · M33 temper comparison
M33-ANN and M33 HT63-65 are two conditions of the same steel grade, M33: ANN (annealed) versus HT63-65 (hardened & triple tempered). The chemistry is identical, so every difference below comes from the condition. M33 HT63-65 is the stronger of the two: yield strength 1,950 MPa (283 ksi) against 550 MPa (79.8 ksi) for M33-ANN, about 3.5 times as much; tensile strength follows at 2,150 MPa (312 ksi) vs 880 MPa (128 ksi). In exchange, M33-ANN is the more ductile: elongation 20% versus 1% for M33 HT63-65, and M33 HT63-65 is harder (800 HV vs 252 HV). M33 HT63-65 runs hotter in service (600°C vs 500°C continuous). On the shop floor, M33-ANN machines more easily (fair vs not recommended) and M33-ANN welds better (poor vs not recommended).
M33-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
M33 HT63-65Choose it when strength drives the design, or when the part sees heat.
M33-ANN vs M33 HT63-65: 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Shear Modulus 84 GPa12.2 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 240 HB · Hardness, Rockwell B 100 HRB
Physical
Density and transition temperatures.
Same in both: Density 8.03 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,230°C2,246 °F · Liquidus Temperature 1,430°C2,606 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.6 µm/m·K5.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3 % IACS · Electrical Resistivity 5.8×10⁻⁷ Ω·m22.8 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.52 V · Corrosion Resistance 16 / 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 30 / 100 · Brazeability / Solderability 55 / 100 · Polishability 78 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 62 MJ/kg26,655 BTU/lb · Embodied Carbon (primary production) 4.6 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 35%
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.
M33-ANN vs M33 HT63-65 — frequently asked
Is M33 HT63-65 stronger than M33-ANN?
Yes. M33 HT63-65 has a typical yield strength of 1,950 MPa (283 ksi) against 550 MPa (79.8 ksi) for M33-ANN — about 3.5 times as much. Tensile strength is 2,150 MPa (312 ksi) vs 880 MPa (128 ksi).
Which condition does FabDigit quote by default, ANN or HT63-65?
ANN is the default M33 condition in the FabDigit quote flow. 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, M33-ANN or M33 HT63-65?
M33-ANN. Its machinability rates fair (38/100) against not recommended (6/100) for M33 HT63-65; for welding the order is M33-ANN first (poor, 18/100) then M33 HT63-65 (not recommended, 8/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in M33-ANN and M33 HT63-65 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.