Alumina and corundum crucibles and boats
Alumina crucibles, boats and lids in 99% and 99.5% Al₂O₃, used up to 1,650 °C in air. We make 79 arc-shaped and cylindrical crucible sizes from 0.5 to 1,500 ml, 67 boat sizes, and flat, outer and inner lids, each in stock or made quickly.
- crucible capacity
- 0.5–1500 ml
- crucible capacity
- crucibles
- 79 sizes
- crucibles
- boats and lids
- 116 sizes
- boats and lids
- high-purity alumina
- C799
- high-purity alumina
Crucibles and boats
Configurations
- Cylindrical
- Rectangular
- Special-shaped
Applications
- Metallurgy
- Chemical processing
- Electronics
- Glass
- Laboratory analysis
Ordering
- Minimum order, non-standard parts
- 100 pcs
- Usually, per item made to your drawing or sample.
- Samples for approval
- 5–10 pcs
- Usually sent for you to approve before the order runs.
- Production lead time
- 25–30 days
- Usual production cycle for non-standard parts.
- Standard sizes from stock
- ~3–7 days
- Stock covers most standard sizes. Small orders ship in about 3 days, bulk orders in about 7 days.
Typical terms. Quantities and dates for your order are confirmed in its quotation.
Crucible, boat and lid sizes
The sizes we make, in stock or made quickly.
Typical dimensions; exact dimensions confirmed in your quotation.
Grades: 99% and 99.5% Al₂O₃. The grade and maximum temperature are confirmed per order.
Arc-shaped crucibles31 sizes
| ml | Top OD | Bottom Ø | Height |
|---|---|---|---|
| Standard | |||
| 3 | 20 | 16 | 17 |
| 4 | 25 | 19 | 18 |
| 5 | 26 | 18 | 21 |
| 10 | 30 | 20 | 28 |
| 15 | 35 | 21 | 30 |
| 20 | 38 | 24 | 35 |
| 25 | 39 | 24 | 38 |
| 30 | 45 | 27 | 39 |
| 40 | 46 | 30 | 40 |
| 50 | 50 | 30 | 48 |
| 70 | 56 | 35 | 56 |
| 100 | 61 | 31 | 60 |
| 150 | 73 | 43 | 67 |
| 200 | 82 | 43 | 70 |
| 250 | 90 | 53 | 76 |
| 300 | 88 | 53 | 85 |
| 500 | 108 | 62 | 108 |
| 600 | 100 | 65 | 128 |
| 800 | 113 | 62 | 140 |
| 1300 | 135 | 83 | 150 |
| Tall | |||
| 3 | 17 | 11 | 25 |
| 4 | 22 | 14 | 24 |
| 10 | 28 | 20 | 32 |
| 15 | 31 | 21 | 35 |
| 20 | 34 | 24 | 39 |
| 30 | 37 | 24 | 45 |
| 50 | 50 | 30 | 54 |
| 120 | 63 | 33 | 73 |
| 150 | 67 | 41 | 80 |
| 400 | 75 | 56 | 122 |
| 500 | 86 | 50 | 140 |
Cylindrical crucibles48 sizes
| ml | OD | Height |
|---|---|---|
| 0.5 | 20 | 4 |
| 1 | 11 | 20 |
| 1.5 | 13 | 25 |
| 2 | 12 | 39 |
| 2 | 30 | 5 |
| 3 | 16 | 28 |
| 4 | 14 | 44 |
| 5 | 16 | 50 |
| 5 | 28 | 17 |
| 6 | 16 | 56 |
| 6 | 19 | 35 |
| 10 | 19 | 58 |
| 10 | 20 | 50 |
| 10 | 30 | 28 |
| 15 | 23 | 60 |
| 15 | 47 | 13 |
| 20 | 35 | 30 |
| 25 | 28 | 58 |
| 30 | 40 | 35 |
| 40 | 35 | 58 |
| 45 | 35 | 70 |
| 50 | 30 | 100 |
| 60 | 40 | 70 |
| 60 | 50 | 50 |
| 65 | 35 | 100 |
| 75 | 45 | 65 |
| 80 | 60 | 40 |
| 80 | 75 | 27 |
| 85 | 50 | 60 |
| 120 | 50 | 80 |
| 120 | 60 | 60 |
| 120 | 90 | 35 |
| 125 | 41 | 137 |
| 130 | 45 | 110 |
| 150 | 50 | 100 |
| 180 | 59 | 87 |
| 200 | 60 | 100 |
| 200 | 100 | 35 |
| 250 | 60 | 120 |
| 300 | 70 | 100 |
| 300 | 80 | 80 |
| 300 | 95 | 60 |
| 400 | 70 | 120 |
| 600 | 100 | 100 |
| 800 | 80 | 200 |
| 800 | 115 | 110 |
| 1300 | 115 | 155 |
| 1500 | 125 | 150 |
Boats67 sizes
| Length | Width | Height |
|---|---|---|
| Rectangular | ||
| 45 | 8 | 6 |
| 50 | 20 | 10 |
| 50 | 20 | 20 |
| 50 | 25 | 10 |
| 50 | 25 | 35 |
| 50 | 40 | 20 |
| 50 | 50 | 25 |
| 52 | 25 | 23 |
| 60 | 30 | 20 |
| 70 | 12 | 7 |
| 75 | 18 | 14 |
| 75 | 20 | 20 |
| 80 | 10 | 10 |
| 90 | 60 | 20 |
| 90 | 60 | 40 |
| 90 | 65 | 30 |
| 90 | 90 | 30 |
| 100 | 10 | 10 |
| 100 | 20 | 20 |
| 100 | 30 | 20 |
| 100 | 40 | 20 |
| 100 | 50 | 30 |
| 100 | 100 | 50 |
| 110 | 24 | 17 |
| 120 | 30 | 15 |
| 120 | 60 | 20 |
| 120 | 60 | 40 |
| 120 | 80 | 30 |
| 120 | 80 | 40 |
| 150 | 20 | 20 |
| Rectangular, perforated | ||
| 73 | 30 | 22 |
| 100 | 24 | 17 |
| 100 | 27 | 27 |
| 100 | 43 | 26 |
| 100 | 56 | 35 |
| 100 | 84 | 35 |
| Boat-shaped | ||
| 27 | 7 | 6 |
| 39 | 10 | 6.5 |
| 40 | 10 | 7 |
| 44 | 11 | 8 |
| 60 | 11 | 8 |
| 77 | 13 | 8 |
| 88 | 15 | 9 |
| 97 | 17 | 12 |
| 115 | 30 | 20 |
| Half-round bottom | ||
| 38 | 34 | 18 |
| 40 | 25 | 17 |
| 40 | 35 | 25 |
| 55 | 35 | 22 |
| 60 | 54 | 24 |
| 65 | 25 | 16 |
| 100 | 20 | 15 |
| 100 | 20 | 20 |
| 100 | 30 | 20 |
| 100 | 40 | 20 |
| 100 | 40 | 25 |
| 100 | 50 | 30 |
| 100 | 65 | 30 |
| 250 | 40 | 18 |
| Trapezoid | ||
| 20 | 20 | 17 |
| 48 | 24 | 14 |
| 60 | 25 | 15 |
| 60 | 30 | 15 |
| 60 | 35 | 15 |
| 80 | 40 | 17 |
| 100 | 23 | 15 |
| 100 | 77 | 27 |
Boats with lids17 sizes
Lids32 sizes
Outer lids (fit over the rim)
Inner lids (stepped, fit inside)
Dimensions in mm, capacity in ml. Sizes differ slightly from maker to maker. Other sizes made to drawing.
Grade and material data
Alumina and corundum. Purity and maximum temperature are confirmed per SKU at quotation.
Full material data| Material class | Al₂O₃ % | Working temperature °C | Hardness, Mohs |
|---|---|---|---|
| High-alumina | >85 | 1300–1450 | 8 |
| Corundum | 99–99.5* | 1600–1800* | 8-9 |
* Stated per SKU: the grade and maximum temperature of each part are confirmed in its quotation.
Guides
Sizes, grades and tolerances in more detail.
- How to clean an alumina crucible, and when to replace it Residue, damage and contamination decide whether a crucible can be reused. What to check before cleaning or ordering a replacement.
- Buyer FAQ: minimum order, lead time, stock, samples, ISO 9001 and test reports What buyers ask before ordering: minimum order, lead time, which sizes are in stock, samples, the ISO 9001 certificate, lab reports and packing.
- How to choose an alumina crucible, lid or boat: shape, capacity and fit Size a crucible from the charge, compare shapes of the same capacity, pick the lid, and decide between a boat and a crucible.
- Crucible materials compared: porcelain, quartz, alumina, zirconia, graphite and platinum Which crucible material to use for what: each maker’s temperature limit, the chemicals that attack it, thermal shock, and where alumina fits.
- Alumina density, melting point and thermal properties by purity Density in g/cm³ and kg/m³, melting point, thermal conductivity and expansion for 96% and C799 alumina, with our forming-method data and a weight calculator.
- Alumina or quartz tube for a tube furnace: temperature limits, vacuum and heating rates When a quartz work tube is enough, when you need alumina, and what furnace makers say about vacuum, heating rates and sag. With our alumina tube sizes and the boats that fit inside.
- Alumina maximum temperature: why tubes are rated 1,600 °C or 1,800 °C, and what lowers it Why the same alumina is quoted at 1,400, 1,600 and 1,800 °C, the limits by grade and by use, and what brings them down: vacuum, load, fast heating, alkali and glass.
- Alumina thermal shock: why ceramic tubes crack, and how to stop it Why high-purity alumina cracks on fast heating or cooling, the published ramp rates and insertion speeds, and what to change for protection tubes, work tubes and crucibles.
- Alumina vs aluminum (aluminium): the ceramic and the metal compared Alumina is aluminium oxide, a white ceramic; aluminium is the metal. Melting point, density and conductivity side by side, the names suppliers use, and how to order the right one.
- Porcelain or alumina crucible: temperature, chemistry and cost When glazed porcelain is enough and when to move to alumina: each maker’s temperature limit, composition, ramp rates, cost and same-capacity alumina sizes.
- Alumina or zirconia crucible: temperature, stabiliser, thermal shock and cost When alumina is enough and when zirconia is worth it: each maker’s temperature limit, which stabiliser, weight and heat flow, thermal shock, chemistry, cost and same-capacity alumina sizes.
- Alumina boat crucibles: sizes, shapes and which boat fits your tube furnace How to check that a boat passes your work tube, a finder for any tube ID, our boats by shape and by furnace tube, lids, heating rates, and what to send.
Questions buyers ask
- Which crucible sizes do you make?
- 79 arc-shaped and cylindrical crucible sizes from 0.5 to 1,500 ml, plus 116 boat and lid sizes. The tables on this page give typical dimensions, and the exact dimensions are confirmed in your quotation.
- What temperature can your alumina crucibles take?
- Our alumina crucibles are used up to 1,650 °C in air. Tell us what you melt or fire in them, and at what temperature, when you ask for a quote.
- What alumina grade are the crucibles?
- We make crucibles, boats and lids in 99% and 99.5% Al₂O₃.
- Do you make boats and lids too?
- Yes. The tables list rectangular, perforated, half-round and trapezoid boats, boats with lids, and flat, outer, inner and rectangular lids.
- Can you make a crucible to our drawing?
- Yes. Other sizes are made to drawing, usually from 100 pieces and in 25–30 days.
- Can we test samples first?
- Yes. We usually send 5–10 free samples, and you pay the courier.
What to send for a quote
- 01Shape: cylindrical, rectangular or special
- 02Outside dimensions, wall thickness and capacity
- 03Lid required or not
- 04What will be melted, fired or analysed, and at what temperature
- 05Al₂O₃ grade
- 06Quantity
Next family:Solid alumina ceramic rods
Request a quote
Get a quotation for crucibles & boats.
Tell us the dimensions, grade and quantity. We confirm the grade, dimensions and tolerances in each quotation. Our yearly lab reports are available on request.