Combination Nipples come in brass aluminum,unplated steel, plated steel, Hastelloy and 316 stainless steel. Sizes for brass is 1" through 4". 316 stainless steel is 1/2" through 8". Aluminum is 1" through 6". Unplated and Plated steel is 2 1/2" through 12". Hastelloy is 2" and 3" only. NPT threaded end no knurl. Recommended for low-pressure discharge and suction service for compatible liquids.