SFWS10 NB Stainless Steel Shaft:NB Linear Systems 12 3/4" Inch (323.9mm) Length 5/8" inch Diameter Shaft SFWS10 NB Stainless Steel Shaft, 5/8" Diameter x 12 3/4" inch Long Shaft, the shaft is made of stainless steel, the shaft is 440C Stainless Steel, it is Case hardness is Rockwell 52-C56, the shaft is single end threaded.