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Suprasil vs ULE 7972

Glass · grade comparison

Suprasil and ULE 7972 are both glass grades. Suprasil is harder — 850 HV against 550 HV for ULE 7972 — which matters for wear surfaces and threads. Suprasil is stiffer (72.5 GPa vs 67.6 GPa).

SuprasilChoose it when surface hardness matters.

Suprasil vs ULE 7972: properties

SuprasilULE 7972

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

72.5 GPa10.5 Msi
67.6 GPa9.8 Msi

Shear Modulus

31 GPa4.5 Msi
29 GPa4.2 Msi

Bulk Modulus

37 GPa5.4 Msi
34 GPa4.9 Msi

Elongation at Break

0%
—

Flexural Strength

67 MPa9.7 ksi
50 MPa7.3 ksi

Shear Strength

70 MPa10.2 ksi
—

Fracture Toughness (K_IC)

0.75 MPa·√m0.68 ksi·√in
0.7 MPa·√m0.64 ksi·√in

Hardness, Vickers

850 HV
550 HV

Hardness, Knoop

600 HK
460 HK

Same in both: Poisson's Ratio 0.17 · Tensile Strength (Ultimate) 50 MPa7.3 ksi · Compressive Strength 1,100 MPa160 ksi · Hardness, Mohs 6

Physical

Density and transition temperatures.

Density

2.2 g/cm³0.08 lb/in³
2.21 g/cm³0.08 lb/in³

Melting Point (Solidus)

1,713°C3,115 °F
—

Refractive Index

1.459
1.483

Light Transmission

93%
90%

Same in both: Porosity 0%

Thermal

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

Thermal Conductivity

1.4 W/m·K0.8 BTU/hr·ft·°F
1.3 W/m·K0.76 BTU/hr·ft·°F

Specific Heat Capacity

750 J/kg·K0.18 BTU/lb·°F
767 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

0.52 µm/m·K0.29 µin/in·°F
0 µm/m·K0 µin/in·°F

Max Service Temperature (continuous)

900°C1,652 °F
890°C1,634 °F

Min Service Temperature

-269°C-452 °F
-270°C-454 °F

Electrical

Conductivity and insulation.

Dielectric Strength

30 kV/mm762 V/mil
25 kV/mm635 V/mil

Dielectric Constant (1 MHz)

3.75
4

Dissipation Factor (1 MHz)

2×10⁻⁴
0.001

Same in both: Electrical Resistivity 1×10¹⁶ Ω·m3.94×10²³ µΩ·in · Volume Resistivity 1×10¹⁸ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

96 / 100
92 / 100

Manufacturability

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

Machinability

10 / 100
15 / 100

Polishability

99 / 100
97 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

180 MJ/kg77,386 BTU/lb
200 MJ/kg85,985 BTU/lb

Embodied Carbon (primary production)

12 kg CO₂/kg
14 kg CO₂/kg

Embodied Water

120 L/kg14.4 gal/lb
150 L/kg18 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

32.9 MN·m/kg
30.6 MN·m/kg

Same in both: Specific Strength (UTS / density) 23 kN·m/kg · Thermal Diffusivity 0.8 mm²/s

Strength versus weight

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

501002005002.533.5Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilitySuprasilULE 7972
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Suprasil vs ULE 7972 — frequently asked

What is the difference between Suprasil and ULE 7972?

Suprasil and ULE 7972 are both glass grades. Suprasil is harder — 850 HV against 550 HV for ULE 7972 — which matters for wear surfaces and threads. Suprasil is stiffer (72.5 GPa vs 67.6 GPa).

Which is cheaper, Suprasil or ULE 7972?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, Suprasil or ULE 7972?

ULE 7972. Its machinability rates poor (15/100) against not recommended (10/100) for Suprasil.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Suprasil and ULE 7972 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.