RIDGID 47745 Threading Machine Dies, Right-Handed Alloy NPT Pipe Dies with Nominal Pipe Size of 1/2-Inch to 3/4-Inches for Universal Die Heads Fits RIDGID NPT Universal Machine Die Head Nos. 504A, 711, 713, 811A, 815A, 816, 817 and 842 Alloy threading die material Threading dies have capacity of 1/2-inch to 3/4-inch Right-Hand, NPT (National {American} Pipe Tapered) thread RIDGID 47745 NPT dies have 14 TPI (Threads Per Inch)