The Square section grips into the part being fixed (typically wood). It prevents the bolt from turning when the nut is tightened. Hot Dipped Galvanized assemblies should be used exclusively. If you use a HDG bolt you must also use a HDG nut.To "go green" and reduce our use of plastic all product quantities will be packaged in as few packages as possible. Listing photo is generic for the fastener type listed in this listing and is not to scale. Please refer to the description for fastener details. We will respond with the requested information quickly. This item is in the category "Business & Industrial\Fasteners & Hardware\Screws & Bolts". The seller is "albanycountyfasteners-ny" and is located in this country: US. This item can be shipped to United States, all countries in Europe, all countries in continental Asia, Canada, Mexico, Australia, Guatemala, New Zealand, Fiji, Papua New Guinea, Solomon Islands, Sierra Leone, Nauru, Wallis and Futuna, Anguilla, El Salvador, Gambia, Dominican Republic, Malaysia, Cameroon, Guyana, Taiwan, Macau, Oman, Suriname, Tonga, United Arab Emirates, Kenya, Argentina, Guinea-Bissau, Eritrea, Senegal, Togo, Saint Kitts-Nevis, Morocco, Qatar, Burundi, Saint Vincent and the Grenadines, Iraq, Equatorial Guinea, Thailand, Mauritania, Belize, Philippines, Aruba, Democratic Republic of the Congo, Republic of the Congo, Western Sahara, Colombia, Israel, Kuwait, Benin, Algeria, Bermuda, Montserrat, Zambia, Antigua and Barbuda, Vanuatu, Ecuador, Swaziland, Ethiopia, Niger, Tanzania, Laos, Burkina Faso, Panama, Singapore, Ghana, Djibouti, Chile, Cape Verde Islands, Mali, Botswana, Cambodia, Madagascar, Saint Pierre and Miquelon, Indonesia, Vietnam, Cayman Islands, Paraguay, Saint Helena, Lebanon, Seychelles, Liberia, Rwanda, Bolivia, Hong Kong, Central African Republic, Gabon Republic, Lesotho, Nigeria, Zimbabwe, Mauritius, Saint Lucia, Jordan, Guinea, British Virgin Islands, Côte d'Ivoire (Ivory Coast), Turks and Caicos Islands, Chad, Kiribati, Grenada, Costa Rica, Haiti, Greenland, Yemen, Saudi Arabia, Bahamas, Bahrain, Trinidad and Tobago, Malawi, Angola, Nicaragua, Tunisia, Uganda, Brazil, Turkey, Western Samoa, Tuvalu, Egypt, Jamaica, Mozambique, Namibia, Niue, Peru, South Africa, Brunei Darussalam, Honduras.