Brass Bulkheads with Bite-Style Barbs. 10-32 inch UNF mounting Threads for 1/16 inch, .078 inch, and 3/32 inch. 1/4-28 inch mounting Thread with 1/16 inch thru hole to 5/32 inch Barb. 5/16-24 inch mounting Thread with a 1/16 inch thru hole to 3/16 inch Barb. 3/8-24 inch mounting Thread with a 1/16 inch thru hole to 3/8 inch Barb. Mixed sizes are available for Straight and Elbow models.