You have successfully added from to your part list.
CF flanges are available with UNC or UNF tapped and untapped holes. Metric tapped or helicoiled holes can be ordered as specials. Tapped flanges have through holes, so bolts may protrude slightly from the back of the flange when fastened to an untapped flange. Untapped CF flanges can be fastened to each other with stainless steel bolts and hex nuts or plate nuts. 12-point bolts are available for CF flanges from 2¾ to 10 inch ODs. Silver plated bolts are available upon request to eliminate the need for anti-seize compound in clean room environments.