Glass Bead Conversion Chart
Glass beads used in abrasive blasting cabinets come in different sizes just like sandpaper comes in different sizes and grades. 60-100 mesh is the fastest cleaning size, and cleaning time increases as bead size increases or decreases.
The larger the bead size the lower the maximum impact velocity, a good rule of thumb is 80 psi maximum blasting pressure for siphon and 40 psi for direct pressure using a pressure pot assembly.
(Chart is for reference only. Please consult glass bead manufacturers for exact specifications.)
| U.S. STANDARD SCREEN SIZE |
MIL. SPEC. (PRF-9954D) |
MIL. SPEC. (S-13165B) |
COMMON BRANDS | SAE (J-1173) |
BEAD SIZE RANGE (DIA., INCHES) |
|||
|---|---|---|---|---|---|---|---|---|
| FLEX-O-LITE (BLAST-O-LITE) |
POTTERS (BALLOTINI) |
CATAPHOTE (MICROBEAD) |
ZERO | |||||
| 12-14 | No. 1 | BT 1 | 1 | 801-201 | .0661-.0555 | |||
| 14-20 | No. 2 | BT 2 | 2 | 801-202 | .0555-.0331 | |||
| 20-30 | No. 3 | 331 | BT 3 | 3 or A | MS-XGX | 801-203 | GB-70 | .0331-.0234 |
| 20-80 | AA | .0331-.0070 | ||||||
| 25-35 | 280 | MS-XPX | .0283-.0197 | |||||
| 25-45 | AAA | MS-XP | .0283-.0171 | |||||
| 30-40 | No. 4 | 232 | BT 4 | 4 or B | 801-204 | GB-50 | .0234-.0165 | |
| 35-45 | 197 | .0197-.0171 | ||||||
| 35-60 | MS-P | .0197-.0098 | ||||||
| 40-50 | No. 5 | 165 | BT 5 | 5 | 801-205 | GB-35 | .0165-.0117 | |
| 40-60 | BOL 21 | C | .0165-.0098 | |||||
| 40-70 | MS-XHX | .0165-.0083 | ||||||
| 45-60 | 138 | .0171-.0098 | ||||||
| 50-70 | No. 6 | 117 | BT 6 | 6 or D | 801-206 | GB-25 | .0117-.0083 | |
| 50-80 | BOL 23 | AB | MS-XH | .0117-.0070 | ||||
| 60-80 | No. 7 | 98 | BT 7 | 7 or E | 801-207 | GB-20 | .0098-.0070 | |
| 60-100 | BOL 24 | MS-H | .0098-.0059 | |||||
| 60-120 | AC | .0098-.0049 | ||||||
| 70-100 | No. 8 | 83 | BT 8 | 8 or F | 801-208 | GB-18 | .0083-.0059 | |
| 70-140 | BOL 25 | AD | MS-MH | .0083-.0041 | ||||
| 80-120 | No. 9 | 70 | BT 9 | 9 or G | 801-209 | GB-15 | .0070-.0049 | |
| 100-140 | H | .0059-.0041 | ||||||
| 100-170 | No. 10 | BT 10 | 10 or AE | 801-210 | .0059-.0035 | |||
| 100-200 | BOL 26 | MS-M | .0059-.0029 | |||||
| 120-170 | AG | .0049-.0035 | ||||||
| 120-200 | No. 11 | BT 11 | 11 | 801-211 | .0049-.0029 | |||
| 140-200 | J | .0041-.0029 | ||||||
| 140-230 | No. 12 | BT 12 | 12 | 801-212 | .0041-.0025 | |||
| 140-270 | BOL 27 | MS-ML | .0041-.0021 | |||||
| 170-230 | K | .0035-.0025 | ||||||
| 170-325 | No. 13 | BT 13 | 13 or AH | MS-L | 801-213 | .0035-.0017 | ||
| 170 and Finer | AL | .0035 and Finer | ||||||
| 200-270 | N | .0029-.0021 | ||||||
| 200-325 | BOL 29 | .0029-.0017 | ||||||
| 230-325 | 24 | O | .0025-.0017 | |||||
| 270-400 | P | .0021-.0015 | ||||||
| 270 and Finer | AI | MS-XL | .0021 and Finer | |||||
| 325 and Finer | BOL 30 | AQ | MS-XLX | 801-214 | .0017 and Finer | |||
| 400 and Finer | AS | .0015 and Finer | ||||||
Bold Print indicates the most commonly used glass bead sizes. Mil. Spec. No. 8 is the most commonly used bead size.