Originally posted by: Evadman
The regular sized forks you see at lowes or other stores like that are about 8k and can lift very nearly their own weight, so about 16k at max load, though you could move 3 pallets of concrete on one fork when I was training to show what it felt like, which was a good amount over rated capacity (60 * 60 * 3 = 10,800 lbs). Since there isn't a scale on most forks, you either need to know, or know how the fork's behavior changes when it is at or over capacity so you can correct it.
The 2 propane ones I was a trainer for were 9k and 17k respectively, and the electric ones were 4k, 6k and 14k depending on type. The electric 14k was actually nicknamed the tank because if you hit something, no mater what it was, you were going though it. Pallets, walls, racking didn't matter.
I was called to a store where an associate had actually ran into the generator for the building and knocked it off it's pad, thus knocking out power to the building. And to get that far, the fork had to go though 2 of the concreete protection posts (side by side) and a cinder block and brick beautification wall (not exactly structural because there wan't a roof, but it was a wall nonetheless)
The driver was not one I had trained (thank god) but he forgot the basic premise of forks. The steering wheel is in the back, and if you overload the fork you take the weight off the steering wheel(s). hitting the brake can unload the wheel entirely so you will keep going straight. You need to hit the gas (or go pedal) to load the steering wheel back up to turn if you are going to be a dumbass and overload the fork.
Oh, and number one rule of forklifts. If you are on one, and it is tipping, DO NOT GET OFF. They seem to tip in slow motion, but you can not beat it. You will end up crushed under the cage. Number 2 is don't overload it if you are counting.