FabDigit

High Heat Glass · Glass-Ceramic

Robax

Robax is a high heat glass glass — transparent fireproof ceramic. Typical values: 90 MPa yield, 2.5 g/cm³, rated to 760 °C. Available for CNC machining, Sheet metal at FabDigit.

CNC machiningSheet metalStandard cost $$

Properties

Typical room-temperature values in the Annealed Glass condition. Metric first, imperial in gray. The bars show where Robax sits against the other 8 glass grades in the catalog.

Datasheet

Yield strength90 MPa13 ksi
Tensile strength110 MPa16 ksi
Hardness700 HV665 HB
Density2.5 g/cm³0.09 lb/in³
Specific strength (yield ÷ density)36
Min service temp-200 °C-328 °F
Max service temp760 °C1,400 °F
Electrical conductivity< 0.001 % IACSinsulator
MachinabilityPoor20 / 100
WeldabilityNot recommended5 / 100
FormabilityNot recommended5 / 100

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Against other glass grades

Yield strength90 MPa 13 ksi
54 MPafamily median 77 MPa490 MPa
Tensile strength110 MPa 16 ksi
67 MPafamily median 90 MPa520 MPa
Density2.5 g/cm³ 0.09 lb/in³
2.2 g/cm³family median 2.5 g/cm³2.96 g/cm³
Hardness (HB equiv.)665 HB
503 HBfamily median 585 HB1,093 HB
Max service temp760 °C 1,400 °F
457 °Cfamily median 600 °C1,310 °C
Electrical conductivity< 0.001 % IACS insulator
< 0.001 % IACSfamily median < 0.001 % IACS< 0.001 % IACS
Machinability20 / 100
20 / 100family median 20 / 10020 / 100
Relative cost35
35family median 3535

Strength versus weight in the glass family

Yield strength against density for every glass grade FabDigit runs. Robax is highlighted; hover a dot for its name, or open the interactive family chart.

501002005002.533.5Density (g/cm³)Yield strength (MPa) — log scaleBorofloat 33N-BK7Soda-LimeFused SilicaGorilla GlassZERODURSapphireRobax

Manufacturability

The process limits FabDigit's quote engine applies to Robax. Design inside these and the part quotes instantly; outside them it routes to an engineer.

CNC machining

MachinabilityPoor20 / 100
Cutting speed (rough / finish) /
Minimum wall
Minimum internal radius
Drill depth limit
Best surface (machined / polished)Ra /
Hardenable after machining

Sheet metal

FormabilityNot Recommend5 / 100
WeldabilityNot Recommend5 / 100

Conditions and tempers

How Robax is supplied and what each state is for. The default is what FabDigit quotes unless your drawing says otherwise.

ConditionBest forYield MPaTensile MPaElong. %Hardness
Annealed GlassDefault
Heat Treat State
Standard glass — can still be cut and drilled to size

Heat treatment and post-processing

Operations FabDigit's suppliers routinely run on Robax, ranked by how often they make sense for this grade.

Post-processing

Manual DeburrDeburrstandard
Edge Break (0.5mm)Deburr
CMM InspectionInspection
FAI ReportInspection
Individual BagPackaging

Surface finishes for Robax

Coatings and treatments compatible with glass on the processes Robax runs on. Pick them in the quote configurator or call them out on the drawing.

Marking / Decoration

  • Chemical Etching
  • Dot Peen Marking
  • Electro-chemical Etching
  • Embossing / Debossing
  • Ink Stamping
  • Laser Marking
  • Mechanical Engraving
  • Vibro Engraving / Scribing

Equivalent designations

Standards and trade names that resolve to Robax in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.

Trade names
Schott RobaxStove Glass

Stock forms

Raw-material forms FabDigit sources Robax in.

SheetPlate

Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.