Beverage Fittings Selection Specifications & Conversion Chart
All nominal barbed fitting designations for this website represent the inner diameter (ID) of the tubing for which the barb is designed to fit, e.g. a 1/4″ barb is designed to fit a 1/4″ ID tube. The actual inch or millimeter dimensions represent the outside diameter (OD) of the barb – slightly larger than the tubing ID to insure a proper seal.
Nominal Inch |
Actual Barb OD (Inch) |
Actual Barb OD (mm) |
Matching Thread |
Nominal Millimeter |
| 1/8″ | 0.160 | 4.01 | 4 mm | |
| 5/32″ | 0.180 | 4.52 | 4.4 mm | |
| 3/16″ | 0.250 | 6.35 | 6 mm | |
| 1/4″ | 0.290 | 7.24 | 7/16″ 20 UNF | 6.5 mm/7 mm |
| 5/16″ | 0.340 | 8.71 | 1/2″ 16 UNF | 8 mm |
| 3/8″ | 0.390 | 9.96 | 5/8″ 18 UNF | 9 mm /9.5 mm /10 mm |
| 7/16″ | 0.440 | 11.48 | 11 mm | |
| 1/2″ | 0.530 | 13.51 | 3/4″ 16 UNF | 13.5 mm |
Column Definitions:
Nominal Inch: Barb size designated to match the ID of beverage tubing.
Actual Barb OD (Inch): The actual outside diameter of the barbed fitting in decimal format in inches.
Actual Barb OD (mm): The actual outside diameter of the barbed fitting in millimeters.
Matching Thread: The unified thread standard that is normally used with a nominal inch fitting, e.g. a 1/4″ nut has a 7/16″ 20 UNF thread count.
Nominal Millimeters: Best practice conversion of inch-based fittings onto metric-based beverage tubing, e.g. 1/2″ barb fittings can be used on 13.5 mm OD beverage tubing.
Clamps
Clamp |
Clamp Range (Inches) |
Clamp Range (mm) |
| 0123 | .386 – .484 | 9.8 – 12.3 |
| 0133 | .425 – .524 | 10.8 – 13.3 |
| 0145 | .472 – .571 | 12.0 – 14.5 |
| 0157 | .520 – .618 | 13.2 – 15.7 |
| 0170 | .571 – .669 | 14.5 – 17.0 |