The Belkin RK5028 is a package of 50 Phillips-head 12/14 x ½" screws.
Question: is this the right size for the 66353-X03 Chatsworth 19" rack
Answer: Thank you for your inquiry. According to the manufacturer, the 66353-X03 series of 2-post rack does use #12-24 mounting screws. Additional mounting screws can be found here: http://www.server-rack-online.com/mounting-hardware.html.