Double Ferrule Stainless Steel Compression Fittings have been designed and developed to meet the demands for reliability and high precision standards. The Alco-Lok range includes Imperial and Metric sizes (see data sheets for all sizes).
Plugs
Metric Dimensions (mm)
| T o/d | G Nut |
| 6 | 14 |
| 8 | 17 |
| 10 | 19 |
| 12 | 22 |
| 16 | 27 |
| 18 | 30 |
| 25 | 41 |
Imperial Dimensions (inch)
| T o/d | G Nut |
| 1/8 | 7/16 |
| 3/16 | 1/2 |
| 1/4 | 9/16 |
| 5/16 | 5/8 |
| 3/8 | 11/16 |
| 1/2 | 7/8 |
| 5/8 | 1 |
| 3/4 | 1-1/8 |
| 1 | 1-1/2 |
Caps
Metric Dimensions (mm)
| 6 | 25 | 19 | 17 | 14 | 14 | 16 |
| 8 | 26 | 20 | 18 | 14 | 17 | 17 |
| 10 | 26.5 | 20.5 | 18 | 17 | 19 | 18 |
| 12 | 33 | 23 | 24 | 22 | 22 | 22 |
| 16 | 35 | 24 | 26 | 24 | 27 | 23 |
| 18 | 37 | 24 | 26 | 27 | 30 | 25 |
| 25 | 45.5 | 31 | 36 | 36 | 41 | 29 |
Imperial Dimensions
| 1/8 | 0.81 | 0.63 | 0.53 | 1/2 | 7/16 | 0.53 |
| 1/4 | 0.91 | 0.7 | 0.6 | 1/2 | 9/16 | 0.62 |
| 5/6 | 0.96 | 0.73 | 0.64 | 9/16 | 5/8 | 0.67 |
| 3/8 | 1.01 | 0.76 | 0.66 | 5/8 | 11/16 | 0.72 |
| 1/2 | 1.15 | 0.86 | 0.9 | 13/16 | 7/8 | 0.75 |
| 5/8 | 1.18 | 0.86 | 0.96 | 15/16 | 1 | 0.78 |
| 3/4 | 1.24 | 0.86 | 0.96 | 1-1/16 | 1-1/8 | 0.84 |
| 1 | 1.51 | 1.04 | 1.23 | 1-3/8 | 1-1/2 | 1.03 |
Nuts
Metric Dimensions (mm)
| T o/d | G Nut | L |
| 6 | 14 | 13 |
| 8 | 17 | 13.5 |
| 10 | 19 | 15 |
| 12 | 22 | 17.5 |
| 16 | 27 | 17.5 |
| 18 | 30 | 18 |
| 25 | 41 | 21 |
Imperial Dimensions (Inch)
| T o/d | G Nut | L |
| 1/8 | 7/16 | 0.47 |
| 3/16 | 1/2 | 0.47 |
| 1/4 | 9/16 | 0.51 |
| 5/16 | 5/8 | 0.53 |
| 3/8 | 11/16 | 0.57 |
| 1/2 | 7/8 | 0.69 |
| 5/8 | 1 | 0.69 |
| 3/4 | 1-1/8 | 0.69 |
| 1 | 1-1/2 | 0.82 |
Lock Nuts
Metric Dimensions (mm)
| G Nut | L |
| 17 | 6 |
| 17 | 6 |
| 19 | 8 |
| 24 | 8 |
| 27 | 9 |
| 30 | 9 |
| 41 | 10 |
Imperial Dimensions (inch)
| G Nut | L |
| 0.51 | 0.23 |
| 0.55 | 0.23 |
| 0.67 | 0.23 |
| 0.67 | 0.23 |
| 0.75 | 0.31 |
| 0.94 | 0.31 |
| 1.06 | 0.35 |
| 1.18 | 0.35 |
| 1.61 | 0.39 |
Ferrules
Metric Dimensions (mm)
| T o/d | Front Ferrule Part No. |
| 6 | 6mFC |
| 8 | 8mFC |
| 10 | 10mFC |
| 12 | 12mFC |
| 16 | 16mFC |
| 18 | 18mFC |
| 25 | 25mFC |
Imperial Dimensions (inch)
| T o/d | Front Ferrule |
| 1/8 | 2FC |
| 3/16 | 3FC |
| 1/4 | 4FC |
| 5/16 | 5FC |
| 3/8 | 6FC |
| 1/2 | 8FC |
| 5/8 | 10FC |
| 3/4 | 12FC |
| 1 | 16FC |
AdapterAlco-Lok Accessories
Bulkhead Connectors
Bulkhead Unions
Close Nipple
Coupling
Gauge Adapter
Hex Female Cap 
Hex Male Plug