How to Modify 3/8″ Threaded Bolt-On Caster Wheels to Fit Unthreaded 7/16″ Mount Points on Home Hospital Bed

home hospital bed with messy sheets

If you have a home hospital bed that needs to be relocated easily but can’t find unthreaded caster wheels, this guide might be helpful to you.

The problem that I recently encountered was a very heavy home hospital bed that needed to be moved around easily without being dragged around on a new floor. The particular bed that I was dealing with was manufactured by Thill, Inc in the USA. It is at least 30 years old and exceedingly heavy.

thill manufacturer label on steel frame of bed

It sits on four feet capped with glued-in plastic inserts with 7/16″ holes. Judging by late model home hospital beds, there are caster wheels that lock into these holes. Unfortunately, I couldn’t source four of them within the tight time frame that I was needing to make this bed mobile.

ruler showing mount point is 7/16"

I knew that I could get threaded bolt-on casters with non-marking rubber wheels from Rural King in Waycross, Georgia. However, those caster wheels’ bolts were 3/8″ threaded. I needed a way to make those bolts larger and secure on the bed. I thought of how to build a sleeve that would increase the bolt’s diameter but not be easily compressed with use. I had just finished drinking a canned Starbucks Espresso when I imagined how I could use its aluminum can to build a sleeve.

unopened starbucks espresso and cream drink

My plan was to cut some of these aluminum cans into sheets that I could wrap around the 3/8″ bolt to increase its size to 7/16″ when it was pushed into the mount point on each foot of the bed. Any aluminum can would work, but I had a the Starbucks cans on-hand, so that’s what I used.

drawing of sheet of aluminum being wrapped around caster mounting bolt

Using a razor, I cut the top and bottom of each can off. Then, I carefully cut down the height of the can to create a sheet of aluminum. Then, I used tin snips to cut the sheets of the needed length and width to match the bolts on the caster wheels.

cut up aluminum cans with tin snips and ruler on 12" board

This is approximately what each sheet looked like, but I used ones with cleaner edges for the final assembly.

sheet of aluminum can

I tightly rolled the aluminum sheet around the bolt. Holding it in place with my fingers, I pushed the bolt into the mounting point. If it slid in too easily, I used a longer sheet of aluminum to bulk it up before trying again. The goal was to install the caster wheel securely so that it wouldn’t wobble or fall out if the bed were lifted off the floor.

rolled sheet of aluminum

Once the four caster wheels were installed, the bed could be easily wheeled around on the floor with minimal effort–far easier than trying to lift or drag its heavy mass!

caster wheel installed on hospital bed