Stainless Steel 347LN-1/4 Hard vs 347LN-3/4 Hard
Stainless Steel · 347LN temper comparison
347LN-1/4 Hard and 347LN-3/4 Hard are two conditions of the same stainless steel grade, 347LN: 1/4 Hard (quarter hard) versus 3/4 Hard (three-quarter hard). The chemistry is identical, so every difference below comes from the condition. 347LN-3/4 Hard is the stronger of the two: yield strength 960 MPa (139 ksi) against 545 MPa (79 ksi) for 347LN-1/4 Hard, about 76% more; tensile strength follows at 1,230 MPa (178 ksi) vs 880 MPa (128 ksi). In exchange, 347LN-1/4 Hard is the more ductile: elongation 12% versus 7% for 347LN-3/4 Hard, and 347LN-3/4 Hard is harder (355 HB vs 250 HB). On the shop floor, 347LN-1/4 Hard welds better (80 vs 70 out of 100).
347LN-1/4 HardChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
347LN-3/4 HardChoose it when strength drives the design.
347LN-1/4 Hard vs 347LN-3/4 Hard: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 152 GPa22 Msi · Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Same in both: Density 7.95 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 16.2 W/m·K9.4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.5 µm/m·K9.2 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Max Service Temperature (continuous) 300°C572 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.4 % IACS · Electrical Resistivity 7.3×10⁻⁷ Ω·m28.7 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.05 V
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 45 / 100 · Brazeability / Solderability 65 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 5.2 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 60%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
347LN-1/4 Hard vs 347LN-3/4 Hard — frequently asked
Is 347LN-3/4 Hard stronger than 347LN-1/4 Hard?
Yes. 347LN-3/4 Hard has a typical yield strength of 960 MPa (139 ksi) against 545 MPa (79 ksi) for 347LN-1/4 Hard — about 76% more. Tensile strength is 1,230 MPa (178 ksi) vs 880 MPa (128 ksi).
Which condition does FabDigit quote by default, 1/4 Hard or 3/4 Hard?
Annealed is the default 347LN condition in the FabDigit quote flow (neither 1/4 Hard nor 3/4 Hard). 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, 347LN-1/4 Hard or 347LN-3/4 Hard?
347LN-1/4 Hard. Its machinability rates fair (40/100) against poor (32/100) for 347LN-3/4 Hard; for welding the order is 347LN-1/4 Hard first (very good, 80/100) then 347LN-3/4 Hard (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 347LN-1/4 Hard and 347LN-3/4 Hard 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.