A\u00a0Lag Bolt<\/strong>\u00a0(also known as a\u00a0Lag Screw<\/strong>) is a large, heavy-duty fastener used to join heavy timber or other materials that require a strong connection. Unlike a standard machine bolt, which requires a nut to secure it, a lag bolt is self-tapping and is driven directly into wood or other materials.<\/p>\n It features a\u00a0hexagonal or square head<\/strong>\u00a0designed to be driven with a wrench or socket (not a screwdriver), and a\u00a0coarse, deep thread<\/strong>\u00a0that provides excellent holding power. Because of its size and thread design, a pilot hole must typically be pre-drilled to prevent the wood from splitting.<\/p>\n Lag bolts are manufactured from various materials depending on the strength and environmental requirements:<\/p>\n Surface treatments protect the bolt from corrosion and can also enhance appearance.<\/p>\n Lag bolts are available in both\u00a0Imperial (inch)<\/strong>\u00a0and\u00a0Metric (millimeter)<\/strong>\u00a0sizes.<\/p>\n Thread Type<\/strong>: Coarse, sharp threads designed for wood.<\/p>\n<\/li>\n Standards<\/strong>:<\/p>\n USA<\/strong>: ASME B18.2.1<\/p>\n<\/li>\n Metric<\/strong>: DIN 571 (Hexagon Head Wood Screws)<\/p>\n<\/li>\n<\/ul>\n<\/li>\n Strength Grades<\/strong>:<\/p>\n SAE J429 Grade 2<\/strong>\u00a0(Low carbon steel)<\/p>\n<\/li>\n SAE J429 Grade 5<\/strong>\u00a0(Medium carbon steel, heat-treated)<\/p>\n<\/li>\n SAE J429 Grade 8<\/strong>\u00a0(Medium carbon alloy steel, heat-treated)<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n Lag bolts are essential in construction and heavy assembly where standard screws are insufficient.<\/p>\n Timber Framing & Construction<\/strong>: Securing large wooden beams, posts, and rafters.<\/p>\n<\/li>\n Decking & Fencing<\/strong>: Attaching ledger boards, fence rails, and heavy brackets.<\/p>\n<\/li>\n Furniture Manufacturing<\/strong>: Assembling heavy wooden furniture, workbenches, and shelving units.<\/p>\n<\/li>\n Mounting Hardware<\/strong>: Securing heavy equipment, brackets, and machinery to wooden floors or walls.<\/p>\n<\/li>\n Automotive & Trailers<\/strong>: Attaching wooden bed liners to truck frames or wooden decks to utility trailers.<\/p>\n<\/li>\n Marine & Docks<\/strong>: Building docks, piers, and other saltwater-exposed wooden structures (using stainless steel or bronze).<\/p>\n<\/li>\n Playgrounds & Outdoor Structures<\/strong>: Building pergolas, gazebos, and swing sets.<\/p>\n<\/li>\n<\/ol>\n Situation:<\/strong> Why Lag Bolts are the Right Choice:<\/strong><\/p>\n Strength<\/strong>: Standard wood screws would not provide enough shear strength to hold the deck safely.<\/p>\n<\/li>\n No Access for Nuts<\/strong>: Unlike a through-bolt (machine bolt), a lag bolt can be installed from the outside without needing access to the interior side of the house’s rim joist.<\/p>\n<\/li>\n Holding Power<\/strong>: The coarse, deep threads of the lag bolt bite deep into the solid wood of the house’s rim joist, creating a powerful clamping force.<\/p>\n<\/li>\n<\/ul>\n The Solution:<\/strong> Pilot Holes<\/strong>: They pre-drill clearance holes through the ledger board and pilot holes (slightly smaller than the bolt’s shank) into the house’s rim joist to prevent wood splitting.<\/p>\n<\/li>\n Installation<\/strong>: Using a high-torque drill with a socket attachment, they drive the lag bolts through the ledger board and deep into the rim joist.<\/p>\n<\/li>\n Spacing<\/strong>: They place the lag bolts in a staggered pattern at 16-inch intervals along the ledger board, ensuring the load is evenly distributed.<\/p>\n<\/li>\n<\/ol>\n Result:<\/strong> High Quality Heavy Duty Hex Head Lag Bolt Wood Screws Zinc Plated Carbon Steel Coarse Threads Sizes M6-M20<\/p>","protected":false},"featured_media":4502,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[],"product_cat":[3086],"product_tag":[3353,3193,3120,3122,3121,3354,3350,3351,3352,3100],"class_list":{"0":"post-4500","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-machined-bolts","7":"product_tag-3-8-lag-bolt","8":"product_tag-cnc-bolt","9":"product_tag-cnc-bolts","10":"product_tag-custom-bolt","11":"product_tag-custom-bolts","12":"product_tag-eyelet-lag-bolt","13":"product_tag-lag-bolt","14":"product_tag-lag-bolt-concrete","15":"product_tag-lag-bolt-tv-mount","16":"product_tag-stainless-steel-machine-bolts","18":"first","19":"instock","20":"shipping-taxable","21":"product-type-simple"},"acf":[],"_links":{"self":[{"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/product\/4500","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/comments?post=4500"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/media\/4502"}],"wp:attachment":[{"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/media?parent=4500"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/product_brand?post=4500"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/product_cat?post=4500"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/machinedwasher.com\/id\/wp-json\/wp\/v2\/product_tag?post=4500"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nMaterial<\/h2>\n
\n\n
\n \nMaterial<\/th>\n Properties<\/th>\n Common Use<\/th>\n<\/tr>\n<\/thead>\n \n Low Carbon Steel<\/strong><\/td>\n Good tensile strength, economical, easy to coat.<\/td>\n General indoor construction, furniture assembly.<\/td>\n<\/tr>\n \n Medium Carbon Steel<\/strong><\/td>\n Higher strength than low carbon steel. Often heat-treated for Grade 5 or Grade 8 ratings.<\/td>\n Heavy machinery mounting, structural steel connections to wood.<\/td>\n<\/tr>\n \n Stainless Steel (304\/316)<\/strong><\/td>\n Excellent corrosion resistance. 316 offers superior resistance to saltwater and chemicals.<\/td>\n Marine applications, outdoor decks, coastal construction, food processing equipment.<\/td>\n<\/tr>\n \n Alloy Steel<\/strong><\/td>\n Contains chromium, molybdenum, or nickel for enhanced strength and durability.<\/td>\n High-stress applications, automotive, aerospace jigs.<\/td>\n<\/tr>\n \n Brass \/ Silicon Bronze<\/strong><\/td>\n Corrosion resistant and non-sparking. Often used for aesthetic appeal.<\/td>\n Boat building, decorative timber framing, historical restorations.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\nSurface Treatment<\/h2>\n
\n\n
\n \nTreatment<\/th>\n Description<\/th>\n Application<\/th>\n<\/tr>\n<\/thead>\n \n Plain \/ Black Oxide<\/strong><\/td>\n Minimal corrosion resistance; provides a basic dark finish.<\/td>\n Indoor use only, light-duty applications.<\/td>\n<\/tr>\n \n Zinc Plated (Electro-galvanized)<\/strong><\/td>\n A thin layer of zinc applied electrically. Offers moderate corrosion resistance.<\/td>\n General hardware, furniture, indoor construction.<\/td>\n<\/tr>\n \n Hot-Dipped Galvanized (HDG)<\/strong><\/td>\n A thick zinc coating applied by dipping in molten zinc. Very high corrosion resistance.<\/td>\n Outdoor structures (decks, fences), utility poles, highway signs.<\/td>\n<\/tr>\n \n Mechanical Galvanizing<\/strong><\/td>\n Zinc coating applied mechanically; used when hydrogen embrittlement is a concern.<\/td>\n High-strength steel bolts (Grade 8) for outdoor use.<\/td>\n<\/tr>\n \n Dacromet \/ Geomet<\/strong><\/td>\n A non-electrolytic coating with excellent corrosion resistance and no hydrogen embrittlement.<\/td>\n Automotive under-hood components, high-end fasteners.<\/td>\n<\/tr>\n \n PTFE \/ Teflon Coating<\/strong><\/td>\n Provides lubrication and chemical resistance.<\/td>\n Chemical plants, specialized industrial equipment.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\nSpecifications & Sizes<\/h2>\n
Common Sizes<\/h3>\n
\n\n
\n \nSystem<\/th>\n Diameter Range<\/th>\n Length Range<\/th>\n Common Drive<\/th>\n<\/tr>\n<\/thead>\n \n Imperial (USA)<\/strong><\/td>\n #10 (3\/16″) to 3\/4″<\/td>\n 1″ to 6″ (or longer)<\/td>\n 5\/16″ to 9\/16″ Hex<\/td>\n<\/tr>\n \n Metric (DIN 571)<\/strong><\/td>\n 5 mm to 20 mm<\/td>\n 20 mm to 200 mm<\/td>\n 8 mm to 24 mm Hex<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n Key Parameters<\/h3>\n
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\nApplication Areas<\/h2>\n
\n
\nExcellent Case Example<\/h2>\n
Project: Building a Heavy-Duty Wooden Deck<\/h3>\n
\nA contractor is building a large residential deck. The main support structure involves attaching a\u00a0double 2×12″ laminated ledger board<\/strong>\u00a0to the side of a house. This ledger board will support the entire weight of the deck, so the connection must be extremely strong and secure.<\/p>\n\n
\nThe contractor uses\u00a05\/8″ x 5″ Hot-Dipped Galvanized Hex Lag Bolts<\/strong>.<\/p>\n\n
\nThe deck is securely fastened to the house. The hot-dipped galvanized coating ensures the bolts will resist rust for decades, even in rain and snow. The large hex head and coarse thread provide a connection strong enough to meet building codes and ensure the safety of the family using the deck.<\/p>","protected":false},"excerpt":{"rendered":"