What is a spreader bar attachment?

What is a spreader bar attachment?

A standard attachment you’ll see on many construction sites are fork-mounted spreader bars. If you’re like me, you’ve probably wondered what a spreader bar is anyway? Why are they so common and what do teams do about them?

In this article, we’ll explain a spreader bar attachment, give examples of why one might be used while lifting loads, and show you some examples of high-quality fork-mounted spreader bars.

Key to take away

• Spreader bars convert lifting forces into compressive and tensile forces that stabilize loads.

What is a spread bar?

A spreader bar is an accessory used to distribute weight and keep loads stable during lifting and transportation. These bars are widespread in construction and industrial environments.

The design of a spreader bar is relatively simple, consisting of a fixed or adjustable length of powder-coated rectangular structural steel tubing. The ends of the steel tube will each have a heavy-duty swivel hook that acts as lifting points.

Spreader bars will have swivel hooks at each end and some may have an additional single attachment point in the centre. Adding a center lift point will aid stability with a suspended load as well as help spread the load along the spreader bar.

https://www.youtube.com/watch?v=/AMa6gAndF6w

Why use a spread bar?

The main purpose of a spreader bar is to stabilize and distribute loads along the spreader beam. To begin with, we need to understand the difference between tensile and compressive force.

Compression forces are when an object is pushed and forced into a smaller size. For example, if you push both ends of a bar inward, you would apply a compressive force.

Tensile forces are when an object is stretched and forced to a larger size, essentially the opposite of compressive forces.

When spreader bars are used properly, they convert the lifting force into compressive forces on the spreader bar and tensile forces on the lifted load. The traction force added to the load helps reduce tilt and promotes stability.

Each spreader bar attachment will have at least two lift points (and sometimes more), which helps distribute heavy loads compared to single lift point systems.

Scatter bar designs and options

Not all spreader bars are built the same, and not all spreader bar components are of the same quality. Here are some things to consider when looking at spreader bar accessories.

Fixed and adjustable lengths

Fork mounted spreader bars come in fixed or adjustable lengths. Adjustable length spacer bars slide in and out at both ends and have a pin to lock them at preset lengths.

Adjustable spreader bar sizes are 8′ to 12′, 10′ to 15′ and 13′ to 20′. Lifting capacity changes depending on the length of the spreader bar and boom arms, as less leverage allows for more weight.

Using Haugen’s adjustable fork-mounted spreader bars as an example, we can see the maximum loads below:

• 5000 lbs each end at 63.375”.

• 4000 lbs each end at 110″.

• 3,500 lbs each end at 165″.

• 3000 lbs each end at 201″.

• 2,250 lbs each end at 240″.

In addition, the maximum load of the center point position is 10,000 pounds.

Fork pockets

Any lifting or towing system is only as strong as its weakest part. For this reason, it’s a good idea to consider fork capacity when using a fork-mounted spreader bar.

Fork-mounted spreader bars are commonly used with heavy-duty telehandler forks, typically built with large, robust fork pockets. 3.5″ by 7.5″ fork pockets are standard, with a positive locking system that attaches behind the heel of both forks.

Upper hooks

Top hooks are an option on spreaders to allow them to be used with cranes or telehandlers. Rental stores and customers should consider these options.

Hooks and latches

One unfortunate place that many spreader bar manufacturers will try to save on production costs is the swivel hook itself. The difference between a $10 overseas swivel hook and a $150 US made Crosby hook is substantial in the final quality of your rig.

Taking a look at how the swivel hook and latch attach to the structural tube of the bar also tells you something about the quality of the product. Ideally, the tab holding the swivel hook should fit completely around the structural tube and be fully welded. This transfers the load entirely to the structural beam rather than relying on a single weld to hold the swivel hook to the beam.

It is also important to remember that the compressive forces of the spreader bar work through the swivel hooks and their attachment point to the structural beam. That said, these joins will probably want to bend inwards. This bending force, combined with poor design and metal fatigue, can cause failure.

OSHA approval

Make sure your spreader bar is OSHA approved. This step alone will eliminate many cheap and poorly built spreader bar fittings.

Which spread bar do you recommend?

Haugen Attachments and Star Industries has become the gold standard in telehandler attachments and has been building spreader bars in North America for several decades. Years of experience combined with exceptional engineering make it our top recommendation.

Rigid and adjustable length spreader bars

Haugen spreader bars encompass everything we look for in a spreader bar accessory.

• 72″, 94″ and 144″ Fixed lengths available

• Adjustable 8′-12′, 10′-15′ and 13′-20′ models available

• Made in the USA and OSHA approved

• Includes USA made 5 ton Crosby hooks

• Optional center hook available

• Optional top hooks are available

• 3.5″ by 7.5″ fork pockets with locks behind fork heel

• 10,000 lb. capacity

• Fully welded swivel hook tabs that connect to the structural pipe

To learn more about spread bar attachments, contact us today at 866-990-7543.