Coach screws are designed for metal to timber connections, or to join heavy timbers. Also known as lag bolts or lag screws, they have a square or hexagonal head engineered to be used with a wrench, spanner, or pliers. These screws come in a wide range of sizes, from the very small ones packed with furniture designed to be assembled by the consumer to extremely big ones used in large scale construction projects.Hex head lag wood screw

A lag screw, or lag bolt,coach screw is a full-bodied bolt with square head or hex head, spaced threads,

and a gimlet point. They are generally used to connect heavy lumber and other materials that bear an

intense load. Zinc plated lag screws should be used for wood in non-corrosive environments, while

hot dipped galvanized lag bolts can be used in corrosive environments, such as an outdoor deck.

For even more protection, consider using stainless lag bolts.

Lag bolts are designed for securely fastening heavy timbers (post and beams, timber railway trestles

and bridges) to one another, or to fasten wood to masonry or concrete

Lag bolts are usually used with an expanding insert called a lag in masonry or concrete walls, the lag manufactured with a hard metal jacket that bites into the sides of the drilled hole, and the inner metal in

the lag being a softer alloy of lead, or zinc alloyed with soft iron. The coarse thread of a lag bolt and lag

mesh and deform slightly making a secure near water tight anti-corroding mechanically strong fastening. The main function of wooden screws is to securely connect metal or non-metal parts to wooden
components, which is a detachable connection method
Hexagon wood screws are also called Coach screws or Lag Screws. Usually, Hexagon Wood screw is used for drilling Wooden Board. As for the surface treatment, we can make Yellow zinc plated, Blue-White zinc plated, Hot dip galvanized, Nickle, Chrome, Black zinc, Black oxide, Dacromet, Ruspert, etc.