Benchmark · 4 materials
CsBr vs Borofloat 33 vs N-BK7 vs Soda-Lime
Side-by-side benchmark of 4 glass grades.
PropertiesHow to read this table
- The best value in each row is in bold.
- Values are typical room-temperature figures for the default condition (temper / grade as listed).
- Relative cost is a market tier, not a price — it moves with region and volume.
- Confirm against the certified mill / resin datasheet before design release.
How to read this table
- The best value in each row is in bold.
- Values are typical room-temperature figures for the default condition (temper / grade as listed).
- Relative cost is a market tier, not a price — it moves with region and volume.
- Confirm against the certified mill / resin datasheet before design release.
| Property | CsBr | Borofloat 33 | N-BK7 | Soda-Lime |
|---|---|---|---|---|
| Yield strengthMPaksi | — | 64 MPa9 ksi | 60 MPa9 ksi | 40 MPa6 ksi |
| Tensile strengthMPaksi | — | 70 MPa10 ksi | 70 MPa10 ksi | 70 MPa10 ksi |
| Specific strengthMPa·cm³/g | — | 29 | 24 | 16 |
| Densityg/cm³lb/in³ | — | 2.2 g/cm³0.079 lb/in³ | 2.51 g/cm³0.091 lb/in³ | 2.5 g/cm³0.09 lb/in³ |
| Hardness (HB equiv.)HB | — | 480 HV≈ 456 HB | 610 HV≈ 580 HB | 550 HV≈ 523 HB |
| Max service temp°C°F | — | 450 °C842 °F | 500 °C932 °F | 460 °C860 °F |
| Min service temp°C°F | — | -200 °C-328 °F | -200 °C-328 °F | -200 °C-328 °F |
| Electrical conductivity% IACS | — | < 0.001 % IACSinsulator | < 0.001 % IACSinsulator | < 0.001 % IACSinsulator |
| Machinability/100 | — | Poor20 / 100 | Poor20 / 100 | Poor20 / 100 |
| Weldability/100 | — | Not recommended5 / 100 | Not recommended5 / 100 | Not recommended5 / 100 |
| Formability/100 | — | Not recommended5 / 100 | Not recommended5 / 100 | Not recommended5 / 100 |
| Relative cost | — | $$ Standard | $$ Standard | $$ Standard |
| Processes | CNC, Sheet | CNC, Sheet | CNC, Sheet |
Where each grade sits
One track per property; coloured markers are the compared grades, the shaded band is the glass family 10th–90th percentile and the tick its median.
Yield strength—
54 MPa8 ksifamily median 77 MPa11 ksi490 MPa71 ksi
Tensile strength—
67 MPa10 ksifamily median 90 MPa13 ksi520 MPa75 ksi
Density—
2.2 g/cm³0.079 lb/in³family median 2.5 g/cm³0.09 lb/in³2.96 g/cm³0.107 lb/in³
Hardness (HB equiv.)—
503 HBfamily median 585 HB1,093 HB
Max service temp—
457 °C855 °Ffamily median 600 °C1,112 °F1,310 °C2,390 °F
Electrical conductivity—
< 0.001 % IACSfamily median < 0.001 % IACS< 0.001 % IACS
Machinability—
20 / 100family median 20 / 10020 / 100
Relative cost—
35family median 3535
CsBrBorofloat 33N-BK7Soda-Lime
Strength versus weight
Manufacturing and finishing
| Capability | CsBr | Borofloat 33 | N-BK7 | Soda-Lime |
|---|---|---|---|---|
| CNC machining | — | Yes | Yes | Yes |
| Sheet metal | — | Yes | Yes | Yes |
| Default condition | — | Annealed Glass | Annealed Glass | Annealed Glass |
| Min. machined wall | — | — | — | — |
| Best machined surface | — | — | — | — |
| Heat treatments | — | — | — | — |
| Chemical Etching | — | Yes | Yes | Yes |
| Dot Peen Marking | — | Yes | Yes | Yes |
| Electro-chemical Etching | — | Yes | Yes | Yes |
| Embossing / Debossing | — | Yes | Yes | Yes |
| Ink Stamping | — | Yes | Yes | Yes |
| Laser Marking | — | Yes | Yes | Yes |
| Mechanical Engraving | — | Yes | Yes | Yes |
| Vibro Engraving / Scribing | — | Yes | Yes | Yes |
Typical handbook values for the default condition, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.