Cup Buster – Threaded Cupwheel Removal Tool


Joe Due Designed Custom tool so you can use  Ratchet/ Breaker Bar/ Impact wrench to remove 7″ Thread Arbor Cupwheels on Grinders with Dust Shrouds attached!  Available in 3/8″ or 1/2″ Drive.  Made from Toughest available  AR500 3/8″ Steel Plate.   Designed to use normal readily available 5/16″ or M8 bolts and hardware (you must supply yourself) as drive pins to grab the cupwheel.  Slots allow for a ‘one size fits most’ styles.  Have a favorite Cupwheel this wont fit?   Maybe we can make one specifically for your application – Just ask Brad!


New for 2023 – Introducing the “Cup Buster” ! A Simple Tool to help you remove stubborn 7″ Cupwheels from Surface Grinders with Dust Shrouds attached.  May also work on some smaller diameter cups as well if the cooling holes are large enough but those are very hit and miss.   This product is designed to allow you to get leverage on the cupwheels in order to spin them off, in lieu of using a hammer and chisel to knock ’em loose – stopping damage to the diamond segments as well as the grinder spindles.

How do you use it?  The Cup Buster has slots in to to accomodate 5/16″ or M8 bolts that slip in and stick though the cupwheel cooling holes.    Due to the vast variances in cupwheel designs the bolts will have to be sourced/ bought by you and hand fit/ customized by you for your individual application – so we do not provide any hardware with it.  Generally speaking – using 5/16″ Carriage bolts between 1″ and 1 3/4″ long tend to work in most applications.   The bolts need to be long enough to secure a nut and washer on the backside (pre bending them to your cupwheel shape will help with fitment)  but not too long so it bottoms out on the shroud hardware, which would prevent the cup from turning and also damage the shroud.  Bench test your setup in the shop before your go out into the field for the least amount of troubleshooting and time wasted.  Using Grade 8 Hardware may be advantagous.   Each setup will be unique.

Product is Made from the Strongest available material which is AR500 3/8″ Plate steel (they make snow plow blades out of this stuff).  The Square cutout is setup for either 3/8″ or 1/2″ drive ( you choose either) for a standard ratchet or breaker bar.   We recommend something with around a 18″ long handle to supply good leverage making removal easier.   Harbor Freight has a selection of these for around $20 or any local hardware/ autoparts store would have them readily available.    Also you could use a cordless impact drill.

To keep the cost down these are just painted lightly to keep corrosion away.  You may wish to paint/ powdercoat the item for longevity or to match your company colors. Perhaps paint it an obnoxious color to deter theft or make it easy to find in the toolbox.   We leave that choice up to you.

If you have a favorite setup that this univeral type adaptor does not work for, but love the idea- feel free to email or call and talk to Brad and perhaps he can design one for your specific application.  You would have to provide some basic details and likely send a used / core cupwheel for engineering purposes.  Custom designs will be painted Pink for ease of identification 🙂



Additional information

Weight 1 lbs
Dimensions 1 × 1 × 1 in