Lincoln Service Parts 2 › Lincoln Electric 9SS31643-3 NYLON LOCKNUT, 1" NPT S31643-3 Lincoln Electric 9SS31643-3 NYLON LOCKNUT, 1" NPT S31643-3 Sale Price: $3.44 Original Price: $3.96 NYLON LOCKNUT, 1" NPT PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1 Add To Cart Added! NYLON LOCKNUT, 1" NPT PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1