unfinished milled steel hex nut. (a milled steel locknut is cut from a solid steel sheet rod.) It is 11/16" outside diameter with 1/2" threaded hole (works with 1/4 IPS pipe) Please note the hole size and make sure this is what you need,We combine with other items to save freight.$1 each. Shipping is$2.60 plus $.15 for each additional nut.Combined shipping- to get cheapest shipping costs (when buying different items)please buy what you need (WITHOUT SHOPPING CART) and “request invoice” (BEFORE YOU PAY)so we can send invoice with lower shipping costs.SHOPPING CART DOES NOT SEEM TO WORK FOR COMBINED SHIPPING.