Precision 5 mm diameter NMR tubes are made from quality Pyrex® borosilicate glass for compatibility with ground joints, valves, and vacuum racks. Made using precision bore tubing manufacturing techniques proven most reliable in NMR applications. A complete selection of tubes for all types of NMR spectrometers, from 60 to 600 MHz is available. All 5 mm NMR sample tubes have O.D. = 4.97 + 0.000-0.013 mm. The I.D. of all except basic tubes are 4.20 + 0.013-0.000mm.