What Do You Need to Order a Custom Pulley?

A custom pulley is a precise part. Every pulley is defined by the same short set of dimensions. Once you provide those to JK Pulley & Manufacturing, our job begins. What information do you need to order a custom pulley? Here are the key details we’ll use for your custom pulley work.

Start with diameter. The outside diameter tells us how much stock we’re starting from and whether the part clears everything around it. We turn pulleys from half an inch up to 35 inches. Be sure to measure across the outside edge rather than down in the groove. Give us the pitch diameter, too, if you have it, since that’s the number the belt actually rides on and the one that sets your speed ratio against the mating pulley.

The bore takes a little more detail, and getting it right up front keeps your order moving. We need the finished bore size. Tell us whether you want it left plain or reamed to a tolerance, and whether it’s getting bushed for a taper lock. If you’re matching an existing shaft, give us the shaft diameter and we’ll cut the bore to fit it correctly. We expertly engineer custom pulleys from legacy systems, and a precise bore is what makes a part install clean and seat the way it should. We hold tight tolerances on that work, so a good shaft number pays off.

Then, give us the width and the depth of the keyway, and tell us whether you want a setscrew over it to lock the pulley to the shaft. If you already know the standard keyseat for your shaft size, pass that along. If you don’t, send the shaft measurement and we’ll spec it for you. Between the bore and the keyway, you’ve already answered most of what information you need to order a custom pulley.

Groove profile is the next piece, and it matters more than people expect. A V-belt groove has to match the belt angle so the profile lines up and the belt tracks true. The easiest answer on your end is the belt cross-section stamped on the belt, so tell us that and we’ll match it. We cut the common V-belt sections, from the A and B grooves up through the heavier D and E. The 3V, 5V and 8V families are routine here. We machine rope and cable grooves too, along with timing profiles. Face width comes in at this stage, since the number of grooves sets how wide the pulley has to be. A two-groove part is a different job than a single. If you’re not certain what you have, the markings printed on the old belt usually identify it.

Material comes down to the application. Cast iron handles a lot of the industrial work we see, and we also run steel and aluminum. Bronze and stainless come up often, and we machine plastic when the job calls for it. That choice depends heavily on operating conditions, so it’s worth a sentence on your end. Heat and speed matter. So does a washdown line or a corrosive environment, and heavy shock loads change the picture again. A pulley on a clean indoor conveyor isn’t built the same as one running outdoors through a St. Louis winter. Matching the material to the real heat and duty cycle of the line is what gives a custom part its edge over a generic one. Tell us what the part actually operates in and we’ll steer the material. If it runs at high speed, mention it, because that’s when balancing earns its keep.

Quantity belongs on the list as well. A single replacement runs differently than a production batch. Knowing whether you need one prototype or a recurring run helps us plan the work and price it accurately.

The last item is the simplest to provide and among the most useful to us. Do you have a drawing or a sample? A dimensioned drawing or a solid model gives us nearly everything above at once. If there’s no drawing, send the old part itself. A sample answers a lot of what information you need to order a custom pulley in one step. We do this regularly at JK Pulley & Manufacturing, and an existing pulley often tells us more than a spec sheet would.

If you have most of those answers, you’re ready to request a custom pulley quote. If a few are missing, that’s fine as well. We’ll work through the gaps together. That’s how to order a custom pulley without the guesswork. Send us what you have, even a photo and the part you’re replacing, and we’ll take it from there. Contact us and let’s get your line back in service.