Round Bottom and Erlenmeyer Flasks
Round Bottom Flasks
Below are listed the nominal volumes and respective diameters for standard borosilicate spherical "round bottom" flasks. We receive them as blanks without finished necks, as shown in the photo on the right, and add to them as required. For example the image below on the right shows a 1L blank prepared as a 4-neck flask with a 45/50 female tapered joint, and three 24/40 female tapered joints.
There are small variations in these blanks depending on the manufacturer. Some are specified as "heavy wall", with larger outside diameters. For volumes less than 25ml, we must prepare them from tubing; these small volumes are not available as stock items and are shown in the chart below just for reference.
Designing your glassware around standard sizes will make a big difference in your cost.

Volume, ml | Diam, mm | Diam, in |
5 | 25 | 1 |
10 | 31 | 1.2 |
15 | 35 | 1.4 |
20 | 38 | 1.5 |
25 | 42 | 1.7 |
50 | 48 | 1.9 |
100 | 60 | 2.4 |
125 | 65 | 2.6 |
200 | 76 | 3 |
250 | 83 | 3.3 |
300 | 87 | 3.4 |
500 | 102 | 4 |
Volume, ml | Diam, mm | Diam, in |
1000 | 130 | 5.1 |
2000 | 161 | 6.3 |
3000 | 185 | 7.3 |
5000 | 221 | 8.7 |
6000 | 236 | 9.3 |
10000 | 279 | 11 |
12000 | 295 | 11.6 |
20000 | 345 | 13.6 |
22000 | 350 | 13.8 |
50000 | 457 | 18 |
72000 | 520 | 20.5 |
100000 | 610 | 24 |

Erlenmeyer Flasks
These are the dimensions of standard Erlenmeyer flask blanks. The heights will vary with style; some blanks have unfinished tops.
Nominal volume, ml | Base Diam, mm |
Height, mm |
|
25 ml | 41 | 61 | |
50 ml | 51 | 78 | |
125 ml | 67 | 114 | |
250 ml | 82 | 132 | |
500 ml | 101 | 176 | |
1000 ml | 129 | 216 | |
2000 ml | 160 | 268 | |
4000 ml | 206 | 360 |

For an example, 500ml round bottom blanks proved to be a great starting place to make these porrons, shown at right and prepared from 500ml blank flasks. A decaled fill line is fired on to indicate a proper serving for use at a local restaurant.
Modifying standard blank flask forms is routine.
