Difference Between Regular Sockets and Impact Sockets

Implements used to tighten or loosen fasteners have changed over time, but as the production of steel became more reliable and consistent grade/quality of steel became possible, fastener manufacturing became rapidly standardized along with a litany of tools and implements to fasten them.

What screwdrivers were to screws and riveting hammers were to rivets, spanners, and sockets were to bolts and studs. Spanners were conventionally used to fasten bolts, this changed with the invention of torque wrenches they were more suited to delivering controlled torque as per their setting, which mostly used a tension spring-based mechanism.

Ratchet Wrench

Open Jaw Wrench

Ring Spanner Wrench

Torque wrenches also started having ratcheting mechanisms, which brought forth the advantages of the sockets.

Let us understand what a socket is:

A Socket is a tool that is used to fasten the nuts of Bolts and studs by gripping the (conventionally) hexagonal part of the nut on the outside and applying the torque using a square drive of a wrench.

The amount of torque applied and the socket selected is decided by several factors:

• Diameter of Bolt and Nut A/F (Across Flat) size
• Torque applied
• Geometry of the socket as per space restrictions
• Material of the socket
  Steps to select sockets for torqueing and detorqueing:

1. The diameter of the bolt and the Nut A/F (Across Flat) size.
2. Once this is understood, depending on the environmental factors, and the lubrication around the bolt, one can calculate the torque required.
3. Selection of the right torque wrench is the next step.
4. Once the square drive size of the wrench is known, one can select the appropriate material for the socket that shall be used.
5. The socket can now be selected according to the square drive size and the Nut A/F (Across Flat) Size.

Difference between Regular Sockets and Impact Sockets:

Regular Sockets and their wrenches are made for use with manual and select electric torque wrenches, which provide light torque capacity for applications such as automotive applications, and everyday uses.

Impact sockets are meant for industrial applications wherein the torque value is much higher and the use of power tools such as impact wrenches, hydraulic torque wrenches, pneumatic torque wrenches, electrical torque wrenches along with manual torque wrenches and torque multipliers is a given.

In a scenario where impact wrenches are used, the applied torque and the vibration shall render regular sockets useless, they might crack in a manner that is perhaps even dangerous to the tool user. Compromising on the tool quality to save costs, would definitely jeopardize safety.

What makes impact sockets well-suited for industrial applications:

There are several factors that make them better, viz.

1. Better Material Selection: The materials used for impact sockets usually are made from Chrome Molybdenum Steel Alloy grades such as EN19, EN 24 & EN 47. A known characteristic of this steel allows the socket to sustain shocks and impacts from impact sockets and has a long durability in the face of repeated use.
2. Heat Treatment: The Steel billet, post machining must undergo heat treatment such as annealing to relieve stresses caused by the processes and add to the resistance against shocks and torsional forces.
3. Anti Rust protection: The sockets undergo black zinc plating, this layer is sufficiently applied to allow resistance against rust and other abrasion.
4. Precise Machining and Geometry: Apart from adhering to standard dimensions for impact sockets, shapes introduced such as rounded edges to openings allow the torsional forces to be applied to the flanks of the sockets instead of the corners this disalllows crack formation at the edges.

What type of Impact sockets exist?

Impact sockets can be classified into several types such as the following:

Square Drive Size: The square drive sizes of wrenches are usually divided into imperial sizes in inches most common ones being – ⅜”, ¼”, 7/16”, ½”, 9/16”, ⅝”, ¾”, 13/16”, 1”,  1-½”, 2-½”, 3-½” and #5 Spline Drive. As we know an inch is divided into 16 parts of which these sizes are usually present.

2. Opening Type: According to the Nut location and space restrictions, use of Allen head bolts, we can select from

• 6 Points Hexagon
• InHex Male Hexagon Driver
• Male Square
• 12 Point Double Hexagon Sockets
• 4 Point Square Sockets
• And many more …

3. Nut Size: The Nut size changes according to the Bolt and whether it is a heavy hex nut or a finished nut, Sockets can be selected accordingly

4. Materials and Socket Geometry: According to the Square drive-to-opening ratio 4 different predominant geometry types for impact sockets exist. Additionally, the impact socket materials can be selected according to the amount of torque and operating conditions.

Types of Sockets Geometry (Drive to Hex Ratio)

Type A — Type B — Type C — Type D

5. Variant according to function: Various functions call for different types of sockets such as the following:

• Magnetic
• Extenders
• Torsion Bars
• Thin Wall Long
• Long and standard length
• Loss of Vibration
• Adapters (Male to Male / Female to Female)
• Insert Adapters
• Universal Sockets

Conclusion:

Industrial Heavy Impact sockets find use with proven power tools such as Hydraulic Torque Wrenches, Pneumatic Torque wrenches, pneumatic impact wrenches, electric torque wrenches, battery torque wrenches, manual torque wrenches, and Torque Multipliers.

Applications include ones in Oil and gas Sector, Wind Energy Sector, Thermal Power Sector, Nuclear power sector, Mining, Automotive sector, etc. Customized Sockets to fit into specific applications can also be made as per requirements.

• Coauthor: Omkar