There are many types of powered tools that can be found in auto shops and garages around the world. One of the more common types is impact sockets which offer considerable assistance, especially when working with the removal or installation of tires on vehicles.
What is an Impact Socket?
An impact socket is designed to be used with powered impact wrenches or as they are sometimes called impact guns. The wrenches themselves are powered pneumatically by compressed air. The wrenches can also be powered through hydraulic oil, or by electricity (cordless impact wrenches). It is the combination of the impact socket and wrench which creates far greater torque that can be obtained through the use of a manual wrench and socket.
If you are a fan of car racing, then you have seen impact sockets and wrenches used by pit crews to change out lug nuts and remove nuts and bolts from vehicles. The same is true for auto shops and individuals who want more power or torque to remove nuts and bolts that may otherwise be too difficult to do manually.
You can find impact sockets in a wide range of sizes. Typically, from 1/4th up to 1 inch or the equivalent when using the metric system. Many companies that sell impact sockets will include a lifetime guarantee to back up their product.
There are a few things that distinguish an impact socket from the standard ones used on manual tools, such as ratchets and torque wrenches.
- Color: Impact sockets tend to be black
- Metal: Impact sockets are made from chrome molybdenum
- Application: An impact socket is designed to be used with impact wrenches
Chrome molybdenum is a durable, ductile metal which is designed to take vibrations. This is a different metal compared to the chrome vanadium used in standard sockets.
Difference between Impact Sockets Vs Regular Chrome Sockets
While similar in appearance, the biggest difference between an impact socket compared to a regular socket is the amount of impact force it can take without cracking or breaking. They also differ in size, the material used, color, price and the presence of locking pin.
|Standard Chrome Sockets||Impact Sockets|
|Durability||Non-impact sockets tend to crack or shatter when used on impact guns.|
Higher wear resistance. Lower toughness.
|Made for Impact Tools: Ability to withstand high impact force.|
Higher toughness. Slightly lower wear resistance.
|Hardness||48-52HRC (Rockwell)||40-45HRC (Rockwell)|
|Size||Thin wall. Lightweight||More wall thickness and weight.|
|Design||Standard socket design||Locking Pin to keep socket secure.|
Flank drive design to eliminate cracks.
|Color||Silver chrome finish||Black electroplated/coated|
Harder the socket, the more brittle it will be. The impact sockets are hardened and tempered to less hardness when compared to standard sockets. Typically they are hardened to 40-45 HRC on Rockwell scale.
This makes them tougher and reduces the chances of getting cracked.
Size: Wall Thickness
Compared to regular chrome sockets, the wall thickness of the impact socket is much thicker. This is another property that enables them to withstand high impact force resulting from the hammering action of impact tools.
The increase in wall thickness will also make them heavier, which brings me to the next point.
Mass of the Socket
The impact sockets are made thicker for another important reason. The higher the mass of the socket the more force it can exert on to the fastener you are trying to tighten or lug nuts you want to remove.
Do you remember Newton’s laws of motion? Well, the second law of motion states F=ma or Force=Mass x Acceleration. (Actually the impulse force J=mΔv. But I am not a physics professor and I do not want you to get bored discussing physics formula here.) This means, higher the mass of the socket the more force it can apply on to the fasteners.
Material Used for Impact Sockets
Most of the impact sockets available in the market are made out of chrome vanadium or Chrome molybdenum steel. Chrome Vanadium Molybdenum is also used for manufacturing impact wrench sockets.
- Chrome Molybdenum Steel (Cr-Mo): This is an alloy steel that contains chromium (Cr) and Molybdenum (Mo) which is often referred to as Chrome-Moly. The chromium molybdenum alloy steel is the best material for impact sockets because of its high tensile strength which provides ductility and corrosion resistance. The presence of chromium gives steel corrosion resistance and wear resistance. Molybdenum provides higher tensile strength and reduces the chances of deformation.
- Chrome Vanadium (Cr-V): From the name of this alloy steel, you can guess that it contains chromium (approximately 80 to1.10 %) and vanadium (0.18%). This combination provides high wear resistance, toughness, and hardness. The main advantage of chrome vanadium Cr-V sockets is that it costs way less than the Chrome Moly. I have seen some of the Chrome Moly sockets that are proximately 75% more expensive than the chrome vanadium sockets.
Is Chrome Moly impact sockets worth the extra price? Yes. The chromium molybdenum alloy provides the extra “flex factor” to the impact sockets. What I mean by the flex factor is that, unlike the chrome vanadium sockets, the Chrome Moly sockets will not shatter even under worst conditions. In case it gets cracked, you will get enough time to notice it and avoid catastrophic failure. However, keep in mind that other factors like hardness, heat treatment procedure, and the wall thickness also have a significant effect on the strength of an impact socket.
- Chrome Vanadium Molybdenum: Some manufacturers also add molybdenum into the Chrome Vanadium to produce alloy steel that has better toughness than Cr-V steel. This also works well for impact sockets.
- High Carbon Steel: These are low-grade steel that can be hardened. Generally, not recommended for impact-rated sockets.
The impact sockets are designed to be used with impact wrenches, which is what makes the combination so reliable and durable over time. High-quality impact sockets often have flank drive design. This minimizes the possibility of corner cracking and maximizes the output torque and impact force.
What is Flank Drive Design?
The flank drive is a patent anti-slip wrench design by Snap-on tools. The patent has now expired and many other manufacturers are using this design to make wrenches. But the trademark Flank Drive ® is registered by Snap-on tools. So other tool producers are using terms such as “Anti Slip Design” (Proto), surface drive, etc.
In a standard manual socket design, the corners of the fathers are in contact and this where the force is applied. This can cause damages to the fastener heads and if used on impact tools can result in corner cracking. With flank drive design the corners are relieved and the flat surface of the faster is gripped. This provides a firmer grip and increased surface contact ensures lower loss of energy during transmission.
The flank drive design also curtails the risks of the socket slipping and fastener heads getting rounded off.
Another noticeable difference is that impact sockets will have locking pins on the drive socket ends. This allows a ring to be used in conjunction with the locking pins to secure the socket to the wrench. The locking pins help keep the socket connected to the impact wrench, even under high duress situations.
Another difference is the price. Because impact sockets are made out of expensive alloy steel and have more material and are designed to withstand greater stresses, they can be considerably more expensive than their standard counterparts.
You can always tell the difference between impact and standard sockets at a distance by their color. Only impact sockets have the black coating while standard versions tend to be coating with chrome.
Caution: Be aware that power sockets that are used in assembly line machines like power nut runners also are black in color. These are much harder and cannot be used on power tools such as impact driver or wrench. Usually, the power sockets are engraved as NON-IMPACT.
It is true that standard sockets can be used with impact wrenches, but there are safety issues that you need to be aware of before using them in that manner.
Can I use the Regular Sockets with an Impact Wrench?
The short answer is ‘yes’, theoretically, it’s possible. But ‘no’, it’s not practical. The reason is fairly simple. While impact sockets are designed for the rigors, vibrations, and impact of being attached to an impact wrench, standard sockets are not. A normal socket is designed to be used manually, which means that it is designed for situations of lower torque, pressure, and vibrations.
In other words, if you use an ordinary socket on an impact wrench and try to take off a nut that is rusty or perhaps frozen in place, the socket would likely shatter. It simply is not designed to take that type of pressure or vibration for very long,
Can You Use Chrome Sockets on Impact Wrench?
Chrome sockets are nothing but the regular standard sockets. So the above answer should give you a reply to this question as well.
You can use a chrome socket with a breaker bar to remove a stubborn nut. However, if you use the same standard chrome socket on an impact wrench it may get cracked. This is because the main reason why the regular chrome socket gets damaged is not the high amount torque, but the intermittent shock that the impact tool exerts on the socket.
You may have noticed that impact sockets have a black oxide coating. This is designed to prevent rust or corrosion from setting in. It also sets impact sockets apart from other, standard sockets such as those which have chrome plating. While chrome will also prevent rust, it will easily flake away if used with an impact wrench.
This means that you should only use impact sockets with impact wrenches. Avoid sockets that have chrome coating because it will chip or split, causing the socket to become damaged and vulnerable to corrosion.
Can You Use Impact Sockets on a Ratchet?
You may wonder if an impact socket will work on your ratchet. The answer is ‘yes’, but there are some considerations to make before attaching your impact socket to a ratchet. The connection between an impact socket to a ratchet is the same as a normal, manual socket. The fit is the same, so there is no danger in tearing up your ratchet or damaging the impact socket when used manually.
However, impact sockets tend to be thicker and somewhat longer, meaning that you will need more clearance to use an impact socket. This negates one of the biggest advantages of using a ratchet. That is its ability to use a ratchet in tight spaces.
In many situations, this might not be an issue. But in tight situations, it may not be practical. Generally speaking, an impact socket is about 50% thicker compared to a standard socket with most of the thickness concentrated in the corner areas.
It is true that the metal used in impact sockets tends to not only be thicker, but somewhat softer. This is why impact sockets can take the punishment better than standard sockets, which tend to be thinner and more rigid. Despite their advantages, it is generally recommended that you use standard sockets on manual ratchets. However, if you cannot find the right size and an impact socket is available, then, by all means, use that.
Can You Use Impact Sockets with a Torque Wrench or Breaker Bar?
The answer is yes. You could purchase a set of deep well impacts and use it on your breaker bar and a regular wrench. However, there are three things that must consider before you go and buy an impact socket.
- Price: Impact rated sockets are expensive when compared to regular sockets.
- Thickness: Sockets for torque wrenches and breaker bars have relatively thin wall thickness. This allows them to go in narrow spaces.
- Wear Resistance: You might have noticed that the hardness level of impact sockets are much lower compared to chrome sockets. This means that your regular chrome sockets can last longer.as long as you don\t try to use them on impact tools.
Ideally, you should have both impact sockets and regular chrome sockets.
If you are considering using impact sockets, then your decision should be based on whether you have an impact wrench. If so, then purchasing the impact sockets are a must as they are not designed for use with the standard versions. Go ahead and get an impact socket set that contains socket sizes that are commonly used and an impact socket extension.
If you do not have an impact wrench, then sticking to the standard sockets is arguably the best decision because they are considerably less expensive.