ITEM NAME:10PCS 1/4-28 Drive Type Taper Thread Straight Grease Zerk Nipple Fitting Z a.imagelink a:hover.imagelink {color:#db3606;.Thread Size: 1/4-28 SAE-LT Taper Thread Straight Zerk. 10 x Grease Nipple Fitting. OAL: 0.54, Shank: 0.18 Standard, Drive: 5/16 Hex.