Square Head Lag Wood Screws

Every design of the Square Head Lag Wood Screws with manufacturer Xiaoguo® is aimed at ensuring "a tight fit without loosening".

1.Square-shaped head

Both open-end wrenches and adjustable wrenches can be used. Even if the wrench is not perfectly aligned, it won't slip. It is more convenient for use in the wild or in confined spaces. Moreover, the square head is less likely to be rounded when being tightened compared to the hexagonal head.

2.Coarse thread

A wider pitch allows the Square Head Lag Wood Screws to advance a greater distance with each rotation, making the installation faster. The deep tooth profile enables each turn of the thread to grip more wood fibers, and its anti-pulling force is 2-3 times that of ordinary wood screws.

3.The part near the head that does not have threads

When connecting the two wooden boards, the non-threaded part passes through the first board without causing any thread engagement; the threads only grip the second board. As the tightening continues, the second board is pulled towards the first board, and there is no gap between the two boards.

4.Conical tip

After being inserted into the guide hole, it automatically aligns itself and does not tilt. In softwood, the tip can slightly press against the wood to assist in self-drilling; in hardwood, it mainly functions as a guide, and the guide hole is still necessary.

Production process

How are Square Head Lag Wood Screws made?

To produce a screw, starting from a coil of round steel wire, the process involves the following main steps:

1.Cold heading forming (head)

Cut the round steel wire into sections of the required length and insert them into the cold heading machine. The machine uses a huge impact force to cold-harden the head of the steel wire into a square shape.The square head is a one-time molding.

2.Tapping (threading)

Put the semi-finished products that have undergone cold heading into the threading machine.Two threaded shank plates, one on top of the other, hold the blank in place and start to thread the shank.The coarse-threaded screw of the Square Head Lag Wood Screws is formed by extrusion, and the surface of the thread is very smooth without any burrs.

3.Heat treatment

The screws made of carbon steel require heat treatment to enhance their strength.Eliminate brittleness and achieve a balance between strength and toughness.

4.Surface treatment

We will carry out the corresponding surface treatment according to the customer's requirements.

5.Packaging

Using an automatic counting scale, bagging or boxing, labeling, and storing in the warehouse.