Coupling nuts are also known as rod couplings or female thread adapters. Designed to join two externally threaded parts with different thread diameters and pitches. 18-8 stainless steel is functionally interchangeable with type 304 stainless steel. Stainless steel significantly improves resistance to tarnishing or corrosion.DIMENSIONAL ATTRIBUTES Diameter (Nominal): 1/2" Thread Pitch: 13 Diameter (Dimension): 0.5" Nominal Diameter 2: 3/8" Thread Pitch 2: 16 Thread Length (Nominal): 1-1/8" Across Flats (Basic): 5/8" Height (Basic): 1-1/8"PRODUCT ATTRIBUTES Category: Coupling Nuts System of Measurement: Inch Brand: Aspen Fasteners® Form and Design: Reducing Coupling Nuts Drive Style: External Hex Drive Thread Length: Part Thread Thread Direction: Right-Hand Thread Material: Stainless Steel Material Grade: 18-8 Stainless Steel Coating: Uncoated