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Refractory Metal Zr 706-HW vs Zr 706-STA

Refractory Metal · Zr 706 temper comparison

Zr 706-HW and Zr 706-STA are two conditions of the same refractory metal grade, Zr 706: HW (hot worked / as-forged) versus STA (solution treated and aged). The chemistry is identical, so every difference below comes from the condition. Zr 706-STA is the stronger of the two: yield strength 750 MPa (109 ksi) against 390 MPa (56.6 ksi) for Zr 706-HW, about 92% more; tensile strength follows at 900 MPa (131 ksi) vs 545 MPa (79 ksi). In exchange, Zr 706-HW is the more ductile: elongation 21% versus 10% for Zr 706-STA, and Zr 706-STA is harder (320 HV vs 185 HV). On the shop floor, Zr 706-HW machines more easily (fair vs poor) and Zr 706-HW welds better (very good vs fair).

Zr 706-HWChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

Zr 706-STAChoose it when strength drives the design.

Zr 706-HW vs Zr 706-STA: properties

Zr 706-HWZr 706-STA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

545 MPa79 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

390 MPa56.6 ksi
750 MPa109 ksi

Elongation at Break

21%
10%

Reduction in Area

35%
40%

Compressive Strength

410 MPa59.5 ksi
420 MPa60.9 ksi

Shear Strength

325 MPa47.1 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

62 MPa·√m56.4 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

42 J31 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

176 HB
180 HB

Hardness, Rockwell B

87 HRB
88 HRB

Hardness, Vickers

185 HV
320 HV

Same in both: Elastic (Young's) Modulus 97 GPa14.1 Msi · Shear Modulus 36 GPa5.2 Msi · Bulk Modulus 92 GPa13.3 Msi · Poisson's Ratio 0.35

Physical

Density and transition temperatures.

Same in both: Density 6.64 g/cm³0.24 lb/in³ · Melting Point (Solidus) 1,840°C3,344 °F · Liquidus Temperature 1,860°C3,380 °F

Thermal

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

Same in both: Thermal Conductivity 17.1 W/m·K9.9 BTU/hr·ft·°F · Specific Heat Capacity 281 J/kg·K0.07 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 6 µm/m·K3.3 µin/in·°F · Latent Heat of Fusion 155 J/g66.6 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

86 / 100
82 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.15 V

Manufacturability

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

Machinability

40 / 100
30 / 100

Weldability

73 / 100
45 / 100

Formability (cold)

55 / 100
15 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 40% · Castability 25 / 100 · Brazeability / Solderability 20 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 1,300 MJ/kg558,900 BTU/lb · Embodied Carbon (primary production) 78 kg CO₂/kg · Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 20%

Strength versus weight

Yield strength against density for every refractory metal grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

1502003005007001,0001,5005101520Density (g/cm³)Yield strength (MPa) — log scaleZr 706

Zr 706-HW vs Zr 706-STA — frequently asked

Is Zr 706-STA stronger than Zr 706-HW?

Yes. Zr 706-STA has a typical yield strength of 750 MPa (109 ksi) against 390 MPa (56.6 ksi) for Zr 706-HW — about 92% more. Tensile strength is 900 MPa (131 ksi) vs 545 MPa (79 ksi).

Which condition does FabDigit quote by default, HW or STA?

Annealed is the default Zr 706 condition in the FabDigit quote flow (neither HW nor STA). 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, Zr 706-HW or Zr 706-STA?

Zr 706-HW. Its machinability rates fair (40/100) against poor (30/100) for Zr 706-STA; for welding the order is Zr 706-HW first (very good, 73/100) then Zr 706-STA (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Zr 706-HW and Zr 706-STA 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.