Capitol Stampings began supplying split pulleys (or split-steel pulleys) many years ago to greatly reducing warranty costs in the lawn and garden industry. The problem was the traditional stamped and welded pulleys could not always handle the demanding application of high-speed mowers.

The answer was to make pulleys out of a single steel blank, splitting the blank at the end and forming the shape of a traditional pulley. Since the pulley is made out of a single piece of steel, is is incredibly durable with perfect balance and no split line between the two halves of the pulley.

Common Split Steel Pulleys

  • Split steel pulleys from 3” to 11” diameter
  • Double stack pulley’s
  • “F” idler split steel pulley’s
  • Multiple hub styles available
  • Click below to view the tooling that already exists for split steel pulleys:

What is a Split Pulley?

A Split Pulley (or split-steel pulley) is a pulley formed out of a single thickness of metal, blanked and separated (split) at the outer circumference to form a traditional pulley groove. Our typical pulleys diameters range from 3” to 11” with a variety of single groove or double stack configurations.

Split-steel pulleys provide increased strength, reliability, and reduced wear on drive and pump systems. Split pulleys are much stronger than stamped pulleys and are both lighter and stronger than cast iron pulleys.

Since split-steel pulleys are made from a single steel blank, there is no need for balance holes such as what you find with cast iron pulleys. The elimination of balance holes helps keep the pulley stronger and eliminates the costly process of balancing a pulley.

With less weight than cast iron, there is less rotational inertia making it easier for drive components to rotate up to speed. Split pulleys can also be used with an electric clutch brake in some applications (like high-speed mower applications) to stop rotation faster with less wear on the clutch rotor and armature.
It all adds up to mean split pulleys add to the life of drive components, improve overall product reliability, and reduces maintenance cost. Translated, this means both manufacturers and consumers are delighted with the benefits of split-steel pulleys.

How a Split-Steel Pulley is Made

STEP 1: A Blank is Cut

The first step is to create a “blank” or a round piece of sheet steel that will be used to manufacture the pulley.

STEP 2: The Split-Pulley Blank is Cut or Split

The blank spins at a high speed while the knife first cuts the blank in half to the desired depth and then the forming tool forms the pulley groove.

STEP 3: Secondary Operations (if necessary)

If a center hub is needed, we weld it into place.

Most pulleys need plating for corrosion resistance unless it was manufactured from a corrosion resistant material. While something like a zinc phosphate plating is common, there are many different options available, depending on your application.

STEP 4: Packing and Shipping

The pulley is packed in a way optimal for your company and sent to you as you need it. We have experience supplying our customers using JIT systems and are happy to work with your unique needs.

That’s all there is to making split-steel pulleys!

While there are few steps, it takes a lot of experience and know-how to ensure the tooling is correct and the machines are working optimally. The tools also need a lot of ongoing care because splitting steel is hard on the tools.

We are pleased to supply you with our experience and expertise to provide you with high-quality split-steel pulleys for your needs. Whether you need hundreds or hundreds of thousands, we are prepared to serve you today, so please give us a call!