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Stainless Steel 347-1/4 Hard vs 347 Full Hard

Stainless Steel · 347 temper comparison

347-1/4 Hard and 347 Full Hard are two conditions of the same stainless steel grade, 347: 1/4 Hard (quarter hard) versus Full Hard. The chemistry is identical, so every difference below comes from the condition. 347 Full Hard is the stronger of the two: yield strength 1,000 MPa (145 ksi) against 550 MPa (79.8 ksi) for 347-1/4 Hard, about 82% more; tensile strength follows at 1,275 MPa (185 ksi) vs 900 MPa (131 ksi). In exchange, 347-1/4 Hard is the more ductile: elongation 12% versus 6% for 347 Full Hard, and 347 Full Hard is harder (370 HB vs 240 HB). 347-1/4 Hard runs hotter in service (425°C vs 315°C continuous). On the shop floor, 347-1/4 Hard machines more easily (fair vs poor) and 347-1/4 Hard welds better (excellent vs very good).

347-1/4 HardChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

347 Full HardChoose it when strength drives the design.

347-1/4 Hard vs 347 Full Hard: properties

347-1/4 Hard347 Full Hard

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
1,275 MPa185 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
1,000 MPa145 ksi

Elongation at Break

12%
6%

Reduction in Area

40%
20%

Compressive Strength

550 MPa79.8 ksi
1,000 MPa145 ksi

Shear Strength

540 MPa78.3 ksi
750 MPa109 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
480 MPa69.6 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

240 HB
370 HB

Hardness, Rockwell B

100 HRB
82 HRB

Hardness, Vickers

260 HV
385 HV

Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.96 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,425°C2,597 °F

Thermal

How each material carries heat and how hot it can run.

Max Service Temperature (continuous)

425°C797 °F
315°C599 °F

Same in both: Thermal Conductivity 16 W/m·K9.2 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.6 µm/m·K9.2 µin/in·°F · Latent Heat of Fusion 280 J/g120 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
2.3 % IACS

Electrical Resistivity

7.4×10⁻⁷ Ω·m29.1 µΩ·in
7.5×10⁻⁷ Ω·m29.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

66 / 100
62 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.08 V

Manufacturability

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

Machinability

40 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
30%

Weldability

85 / 100
70 / 100

Formability (cold)

50 / 100
20 / 100

Same in both: Brazeability / Solderability 70 / 100 · Polishability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 57 MJ/kg24,506 BTU/lb · Embodied Carbon (primary production) 5.5 kg CO₂/kg · Embodied Water 140 L/kg16.8 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.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scale347

347-1/4 Hard vs 347 Full Hard — frequently asked

Is 347 Full Hard stronger than 347-1/4 Hard?

Yes. 347 Full Hard has a typical yield strength of 1,000 MPa (145 ksi) against 550 MPa (79.8 ksi) for 347-1/4 Hard — about 82% more. Tensile strength is 1,275 MPa (185 ksi) vs 900 MPa (131 ksi).

Which condition does FabDigit quote by default, 1/4 Hard or Full Hard?

Solution Annealed is the default 347 condition in the FabDigit quote flow (neither 1/4 Hard nor Full 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, 347-1/4 Hard or 347 Full Hard?

347-1/4 Hard. Its machinability rates fair (40/100) against poor (30/100) for 347 Full Hard; for welding the order is 347-1/4 Hard first (excellent, 85/100) then 347 Full Hard (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 347-1/4 Hard and 347 Full 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.