Heat Treatment of American Hexagon Socket Bolts

hexagon socket bolts

What is Hexagon Socket Bolts?

Hexagon socket bolts, also known as Allen bolts or socket head cap screws, are fasteners with a cylindrical shaft and a hexagonal socket (recess) on the head. They are tightened or loosened using a hex key or Allen wrench. Hexagon socket bolts are widely used in various industries and applications due to their high torque capabilities and compact design. They provide a secure and reliable connection for assembling parts, machinery, and equipment, and are commonly found in automotive, construction, manufacturing, and DIY projects.

Types of hexagon socket bolts

There are 10 kinds of heat treatment methods for American hexagon socket bolts

1. Normalizing:

The steel or steel parts are heated to the appropriate temperature above the critical point AC3 or ACM for a certain time and then cooled in air to obtain pearlite structure.

2. Annealing:

The hypoeutectoid steel workpiece is heated to 20-40 ℃ above AC3 and cooled slowly in the furnace (or buried in sand or lime) to below 500 ℃ and cooled in air after holding for a period of time.

3. Solution heat treatment:

The alloy is heated to high temperature, and the single-phase zone is kept at constant temperature, so that the excess phase is fully dissolved into the solid solution, and then rapidly cooled to obtain the supersaturated solid solution.

4. Aging:

After solution heat treatment or cold plastic deformation, the properties of alloy change with time when placed at room temperature or slightly higher than room temperature.

5. Solution treatment:

Make all kinds of phases in the alloy fully dissolve, strengthen the solid solution, improve the toughness and corrosion resistance, eliminate stress and softening, so as to continue processing and forming.

6. Aging treatment:

Heating and holding at the temperature of strengthening phase precipitation, so that the strengthening phase precipitation precipitation, hardening, improve the strength.

7. Quenching:

It is a heat treatment process in which the steel is austenitized and cooled at a proper cooling rate, so that the unstable structure transformation such as martensite occurs in all or a certain range of the cross section of the workpiece.

8. Tempering:

A heat treatment process in which the quenched workpiece is heated to an appropriate temperature below the critical point AC1 for a certain period of time, and then cooled in a satisfactory way to obtain the required microstructure and properties.

9. Carbonitriding of steel:

Carbonitriding is a process of simultaneous infiltration of carbon and nitrogen into the surface of steel. Carbonitriding, also known as cyaniding, is widely used in medium temperature gas carbonitriding and low temperature gas carbonitriding. The main purpose of medium temperature gas carbonitriding is to improve the hardness, wear resistance and fatigue strength of steel. The main purpose of low temperature gas carbonitriding is to improve the wear resistance and anti seizing property of steel.

10. Quenching and tempering:

Generally speaking, the heat treatment combining quenching and high temperature tempering is called quenching and tempering treatment. Quenching and tempering treatment is widely used in various important structural parts, especially those connecting rods, bolts, gears and shafts working under alternating load. The mechanical properties of tempered sorbite are better than that of normalized sorbite with the same hardness. Its hardness depends on the high temperature tempering temperature and is related to the tempering stability of the steel and the cross section size of the workpiece, which is generally between hb200 and 350. These are all heat treatment methods of American hexagon socket bolts.

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