Sadly, we've had numerous reports that most of the open frame racks found here https://amzn.to/33v2Owg don't fit our Rackstuds.
Reportedly, the hole size is under specification at 8.9mm when the EIA-310 spec calls for 9.5mm. Even getting some cage nuts in holes this small can be very difficult. Ironically, the Amazon listing actually mentions they meet EIA-310.
As the holes in the racks are undersize, Rackstuds won't be manufacturing a third smaller size to accommodate these racks (and others) with holes below 9.3mm; our lower tolerance limit. If you have one of these racks, please double check before placing an order for Rackstuds as they will most likely not fit. The problem appears to be related to these Open Frame Server Racks as others have been using Rackstuds in other StarTech racks without issue.