Forklift Fork Basics
The widespread use of the modern forklift in industrial environments is aided by a number of specialized tools and accessories. Yet the most important tool used on a forklift is perhaps the most unassuming: the forks. Since the invention of the forklift, forks have evolved from a general purpose tool into a multifaceted spectrum of tools, each designed for a specific use and application. To fully understand the variety and potential uses of forklift forks, it’s important to understand the basic variations. In light of that, we’ve summarized some of the basic features of the fork below:
At a basic level, forklift forks can be broadly classified by how the fork is attached to the forklift carriage. This classification system splits all forks into 2 two primary categories: hook and pin type forks. Hook type forks utilize a pair of metal hooks that allow the forks to slide over the carriage and are used in applications with lifting capacity up to 14,000 lbs. In contrast, pin type forks include a round eyelet at the top of the shank that slides around a carriage shaft and are used in applications with very large, heavy loads.
Forks are further classified by what type of carriage they’re built to fit. The carriage classification system divides carriages – and their associated forks – into four classes based on carriage bar spacing and their maximum rated load capacity:
- Class I – rated for loads up to 2,000 lbs. with carriage bar spacing at 13 inches;
- Class II – rated for loads up to 5,500 lbs. with carriage bar spacing at 16 inches;
- Class III – rated for loads up to 10,000 lbs. with carriage bar spacing at 20 inches; and,
- Class IV – rated for loads up to 17,500 lbs. with carriage bar spacing at 25 inches.
For the most part, there are three basic blade types that you should be familiar with: pallet, polished and tapered and plywood forks. The first thing that comes to mind when most people think about forklift forks are also the most commonly used type: pallet forks. As the name suggests, pallet forks are designed to handle pallets and skids. In terms of design features, pallet forks are relatively thin with a flat top, a slight bottom taper (starting about halfway down the blade) and a blunt tip to avoid damaging pallets and/or loads while stacking.
More specialized than standard pallet forks, polished and tapered forks are designed to facilitate chiseling operation. This is achieved with a thin, fully tapered blade, a square tip with a top or bottom bevel and a smooth, polished finish. These features allow the forks to slide underneath a variety of surfaces without puncturing, tearing or otherwise damaging the load.
A hybridized version of the two previously mentioned blade types, two-stage lumber forks include are wider and thinner than pallet forks to enable the operator to chisel between sheets of plywood. This is accomplished with a two stage taper and a partial polish so that the forks slide in between two sheets of lumber without causing damage while maintaining enough friction to ensure the lumber does not slip off the forks once loaded.
After you’ve decided what type mount and blade type best suits your needs and application, you’ll need to select an appropriate fork length and capacity. To determine how long you’ll need your forks to be, begin by accurately measuring the length of your loads. Using this number as a reference, you’ll need forks that are at least 2/3rds the length of your longest load. At the same time, you’ll want to make sure that the load is always longer than the forks to avoid damaging other loads, pallets or shelving while stacking. To illustrate, let’s pretend that you need to handle loads 90 inches in length. Two-thirds of 90 inches gives you a minimum fork length of 60 inches and a maximum fork length of 90 inches.
Why do some class II and class III forks have the same capacity? Confused
They do not have the same capacity. You can have multiple capacities within a single class (i.e., class II forks with 3,000, 4,000 or 5,000 lb. capacities) but the fork’s class determines its capacity. Some people get these classes confused with the ITA lift truck classifications.
Thank you for clearing that up – I had the same question but it’s the other way around