Steel 817M40 Annealed vs 817M40-T
Steel · 817M40 temper comparison
817M40 Annealed and 817M40-T are two conditions of the same steel grade, 817M40: Annealed versus T (condition T). The chemistry is identical, so every difference below comes from the condition. 817M40-T is the stronger of the two: yield strength 760 MPa (110 ksi) against 470 MPa (68.2 ksi) for 817M40 Annealed, about 62% more; tensile strength follows at 930 MPa (135 ksi) vs 745 MPa (108 ksi). In exchange, 817M40 Annealed is the more ductile: elongation 22% versus 16% for 817M40-T, and 817M40-T is harder (285 HB vs 217 HB). On the shop floor, 817M40 Annealed machines more easily (good vs fair) and 817M40 Annealed welds better (45 vs 35 out of 100).
817M40 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
817M40-TChoose it when strength drives the design.
817M40 Annealed vs 817M40-T: 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 780 MPa113 ksi · Shear Strength 590 MPa85.6 ksi · Fracture Toughness (K_IC) 110 MPa·√m100 ksi·√in · Hardness, Rockwell C 29 HRC · Hardness, Vickers 300 HV
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,416°C2,581 °F · Liquidus Temperature 1,465°C2,669 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 425°C797 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.48×10⁻⁷ Ω·m9.76 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 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: Brazeability / Solderability 45 / 100 · Polishability 68 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 33 MJ/kg14,187 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
817M40 Annealed vs 817M40-T — frequently asked
Is 817M40-T stronger than 817M40 Annealed?
Yes. 817M40-T has a typical yield strength of 760 MPa (110 ksi) against 470 MPa (68.2 ksi) for 817M40 Annealed — about 62% more. Tensile strength is 930 MPa (135 ksi) vs 745 MPa (108 ksi).
Which condition does FabDigit quote by default, Annealed or T?
T is the default 817M40 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, 817M40 Annealed or 817M40-T?
817M40 Annealed. Its machinability rates good (58/100) against fair (45/100) for 817M40-T; for welding the order is 817M40 Annealed first (fair, 45/100) then 817M40-T (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 817M40 Annealed and 817M40-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.