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

1L 4 neck flask (/images/uploads/2012.jpg)

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

Erlenmeyer Flask Blanks (/images/uploads/2389.jpg)

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.