| 2A | 22.0” |
| 2B | 25.0” |
| 3A | 26.0” |
| 3B | 30.7” |
| 4A | 32.9” |
| 4B | 38.0” |
ISO/ITA Fork suspension is the most common method of fork mounting. The international standard is ISO 2328 that defines all measurements. There are 5 truck rated capacities (1 thru 5) and each of those have a form of either "A" or "B". The most important measure is the drop clearance (pictured below). All forks on this site are drop "A".
| Class | Rated forklift cap (lbs) | ISO Form | Drop a |
| 1 | 0-1,999 | 1A | 3” |
| 1B | 4.5” | ||
| 2 | 2,000- 5,500 | 2A | 3” |
| 2B | 6” | ||
| 3 | 5,501-10,000 | 3A | 3” |
| 3B | 8” | ||
| 4 | 10,001-17,500 | 4A | 5” |
| 4B | 10” | ||
| 5 | 17501-24000 | 5A | 5” |
| 5B | 10.1” |
The capacities listed in the catalog section are the maximum weights being placed on the frame supporting the ball or hitch device (they have their own capacities), the towing capacity will be determined by the forklift, the forklift's forks, and other factors.
Most forklift forks are made to metric equivalents, based on the most popular
| Nominal width | Metric | Inches |
| 4” | 100mm | 3.94 |
| 5” | 122mm | 4.8 |
| 6” | 150mm | 5.91 |
| 7” | 180mm | 7.09 |
| 8” | 200mm | 7.87 |
| 10” | 250mm | 9.84 |
This may be useful information when considering accessories like Fork Extensions, Fork Mounted Booms, Trailer Spotters, Self Dumping Hoppers, Work Platforms, or any product that mounts to the forks.