A 'Not Expensive' trolley (metal 4 shelf) was purchased from Amazon. On receipt it was clear that the cross members were held on the uprights by M5 screws bearing directly on the upright tubes. As this trolley would get a lot of use I felt I needed saddle washers to spread the load and extend the working life. I had to carefully open out the 4mm holes to 5mm without damaging the washers. Once this was done they worked (are working) perfectly! Only needed 32 so special order not viable. Ordered 34, only broke one! One off requirement but would not hesitate to repeat if need arose!