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Stainless Steel HH-F vs HH-ST

Stainless Steel · HH temper comparison

HH-F and HH-ST are two conditions of the same stainless steel grade, HH: F (as fabricated) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. HH-F is the stronger of the two: yield strength 310 MPa (45 ksi) against 260 MPa (37.7 ksi) for HH-ST, about 19% more; tensile strength follows at 585 MPa (84.8 ksi) vs 540 MPa (78.3 ksi). In exchange, HH-ST is the more ductile: elongation 25% versus 15% for HH-F, and HH-F is harder (185 HB vs 165 HB).

HH-FChoose it when strength drives the design.

HH-STChoose it when the part is bent, formed or impact-loaded.

HH-F vs HH-ST: properties

HH-FHH-ST

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

585 MPa84.8 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
260 MPa37.7 ksi

Elongation at Break

15%
25%

Reduction in Area

20%
30%

Shear Strength

380 MPa55.1 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
220 MPa31.9 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

34 J25.1 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

185 HB
165 HB

Hardness, Rockwell B

90 HRB
85 HRB

Hardness, Vickers

195 HV
173 HV

Same in both: Elastic (Young's) Modulus 190 GPa27.6 Msi · Shear Modulus 73 GPa10.6 Msi · Bulk Modulus 150 GPa21.8 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.72 g/cm³0.28 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.

Thermal Conductivity

14.2 W/m·K8.2 BTU/hr·ft·°F
14 W/m·K8.1 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 15 µm/m·K8.3 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 1,090°C1,994 °F · Min Service Temperature -45°C-49 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

8.5×10⁻⁷ Ω·m33.5 µΩ·in
8.7×10⁻⁷ Ω·m34.3 µΩ·in

Same in both: Electrical Conductivity 2 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

62 / 100
66 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V

Manufacturability

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

Machinability

30 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
40%

Weldability

45 / 100
50 / 100

Formability (cold)

8 / 100
12 / 100

Same in both: Castability 75 / 100 · Brazeability / Solderability 35 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 48 MJ/kg20,636 BTU/lb · Embodied Carbon (primary production) 4 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 75%

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 scaleHH

HH-F vs HH-ST — frequently asked

Is HH-F stronger than HH-ST?

Yes. HH-F has a typical yield strength of 310 MPa (45 ksi) against 260 MPa (37.7 ksi) for HH-ST — about 19% more. Tensile strength is 585 MPa (84.8 ksi) vs 540 MPa (78.3 ksi).

Which condition does FabDigit quote by default, F or ST?

F is the default HH 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, HH-F or HH-ST?

HH-ST. Its machinability rates fair (35/100) against poor (30/100) for HH-F; for welding the order is HH-ST first (fair, 50/100) then HH-F (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in HH-F and HH-ST 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.