Lot of 300 pcs, slotted machine screws size is 5/16-18; 1/2" long These are shipped free to you in a flat rate USPS box. Message me for larger or smaller lots. 61401-19 Shipping: I am committed to shipping by the 2nd business day after order is placed and paid for. In many cases, items are shipped same or next day. Shipping is by USPS Ground Advantage for lightweight packages, or Priority Mail for others. I also utilize UPS Ground. I do NOT mark up shipping and never charge you for materials, boxes, tape, etc. Payment: Please pay for item upon checkout or within 3 business days of getting an invoice. Warranty: All items are warranted as described and useful as intended for a 30 day period from the date of arrival. I am not a manufacturer or retailer, and do not honor manufacturer warranties. Item evaluations: In cases of damages, non-receipt, shortages, and loses during transit, all pieces in any multi-lot offering will be presumed to have an equal and proportional value to that of the entire lot. Please contact me if you need to return an item. Thank You! I have sold since 1999 and take pride in serving my customers to the satisfaction of their needs. Instead of leaving negative or neutral feedback, please contact me FIRST to resolve any problems with your shipment or your merchandise.