What Size Bits Does an Impact Driver Use?

An impact driver is a wide range of used power tools for both drilling holes and driving screws. When using an impact driver we should know its collet size, and bit size in order to select the bits. So let’s see, what size of the bit will use an impact driver.

Normally, an impact driver can use 1/4” (6.35mm) bits for its quick-change chuck (collet). Although the torque is varied, all types of available impact drivers use the same size impact driver bits.

When we consider the impact driver bit sizes, we should know many additional things. So let’s see, all in detail step by step!

Are Impact Driver Bits Universal?

We can consider all sizes of impact driver bits are 1/4”(6.35mm) by size. This is common for all types of available brands of impact drivers. So finally we can agree, impact driver bits are universal.

Although, impact drivers can work with different torques their collet size and bits size will not change. It is common for all brands. So we can use the same impact driver bit for any tool. 

Impact bits are hex shapes of their cross-section. It helps to transfer a higher amount of torque to the screw head.

Impact Driver Collet and Drill Chuck

Drill Chuck and Impact Driver Collet

Impact drivers and drills both have chuck. Normally, we use circular drill bits in drilling tools and hex cross-sectional bits for impact drivers.

Chuck is the driver bit or drill bit mount area of the tool. In drills, we can see 3 jaws chuck that can tight by turning. When the chuck is turned, 3 jaws come close and tight the drill bit well.

But considering the impact drivers, we can see a quick-change chuck. We can change driver bits easily when we use a quick-change chuck. Another name for this is collet. Collet can push back and drop the driver bit inside the collet. When it moves front, it will automatically tight the driver bit.

When we consider the tool changing time, impact drivers will take minimum time and drill take maximum time due to tightening chuck.

Impact Wrench Head and Impact Driver Collet

Impact Driver Collet and Impact Wrench Head

As for me, I have observed in many places, that people looking for 1/2″ impact drivers, 3/8″ impact drivers etc.

Is this real?

Actually, this is a total misunderstanding. Because no brands manufacture impact driver collect size more than 1/4″ (Let me know if you know). So people may search for such tools every time.

Impact drivers collet size is less than impact wrench anvil size. Because impact drivers are used to drive screws into drywalls, soft materials such as wood etc. But impact wrenches heads have different sizes.

That can varied with 1/2″, 3/8″, 1″ etc. Impact wrenches use for tightening or removing lug nuts. Hence those require a higher toque than drive square. Hence, those tools have higher size heads. These heads are of two types. Pin detent and friction ring are them. Pin detent is suitable for quick change impact wrenches and a friction ring is the safest one.

Why Are Hex Shank Bits Used for Impact Drivers?

I think you now understand that an impact driver is used to operate under high torque. The reason for this special hex shape is that the drill bit is more likely to grind under such high torque, but the hex shape can be used to avoid that grinding. The grinding will change the shape of the drill bit. The variated drill bit cannot be used properly with an impact driver.

And also, the special shape of the drill bits used in impact drivers makes it possible to tighten or secure the safety screws or nuts under high torque. But what is commonly used in drills is the circular shape. Therefore, it cannot be operated under high torque.

These hex shank bits are coated. This Ti-N coating on impact drill bits extends their lifespan. Excess heat dissipated due to heavy loading during drilling operations.

This special shape reduces the pressure on the hand of the drill bit user and reduces the problems that may arise during the installation of the drill bit.

Suitable Bit Sizes for Using an Impact Driver As a Drill

Adaptor For Using Impact Driver As a Drill

It is a real solution to use an impact driver as a drill. The impact driver and drill both have rotational movement. But impact drivers have perpendicular hammering action which can increase the torque of the tool. But regular drills only have the rotational movements except for hammering tools.

So we can use an impact driver as a drill for soft material. We are not able to use an impact driver to drill the hardest material such as concrete, stones, bricks etc. We need a hammering action tool to drill this material.

As I explained above, impact drivers use hex cross sectional bits and drills use circular cross sectional bits. If we need to use a drill bit on impact drivers, we should use an adptor. One of that side is hex shape and another side is with 3 jaws chuck.

Using this chuck we can use any drill bit size, which is compatible with the adaptor.

Due to this structure, we can use an impactdriver as a drill.

Can You Use Hex Bits in a Regular Drill??

Simply put, the answer is yes. The hex bits are used for the impact driver. The collet was designed for the hex shape. The regular drill like SDS drill wants circular shape drill bits. The chuck was designed for the circular shaped drill bits and rounded ended drill bits. Therefore, hex shaped impact driver bits will be used with regular drills. But it is not as efficient as an impact driver

In fact, due to the robustness of the impact drill bits and their ability to be used even under high torque, these beers are even more secure when used with a normal drill. Also keep in mind that impact drill bits can be used in regular drills but regular drill bits are more dangerous than those used in impact drivers.

Read More About – Is An Impact Driver Better Than a Regular Drill? – Find Out Here!

Suitable Bit Sizes for Using an Impact Driver As an Impact Wrench

It is very important to know, whether we can use an impact driver as an impact wrench. So lets see, thier mechanism, usage and tool structure.


Impact drivers have anvil based impact mechanism. But impact wrenches have gear system based impact mechanism. As a result of gear system, impact wrenches produce higher torque than impact drivers. So impact driver toque is measured by in.lbs and impact wrench torque is measured by ft.lbs


Impact drivers use to handle 250 ft.lbs -1500 ft.lbs of torque and impact wrenches can handle 50 ft.lbs – 300 ft.lbs of torque. So Impact drivers use to drive screws and impact wrenches use for lug nuts works.

Tool Structure

Impact drivers are a bit longer than impact wrenches. Impact wrenches are short and more power due to its gear based impact mechanism. Impact drivers use collet for mount the driver bit and impact wrenches use impact sockets with mounting to head of the tool.

When we use impact driver as an impact wrench we should use impact driver to imapct wrench adptor. Those adaptors available with differnet sizes as impact wrenchs sockets availabe.

Read More About – 09 Facts – Is Impact Wrench Worth It?


But remeber the maximum torque that impact driver can produce is not change when you use this adaptors. So imagine of your imapct driver is with 1000 in.lbs will produce 83.33 ft.lb of torque maximum.

Tom Mackency

Tom Mackency

Hi, I am Tom Mackency. It has been 10 years that I have been working as a professional woodworker since 2013. I am really enjoying my carrier by creating many kinds of projects in my workshop. But mostly I like for home improvement projects. Home improvement and DIY projects are the most interesting things for me. More than that, the coolest things are power tools. Those are very precious and efficient than a decade ago. So I try to introduce so many things about power tools, woodworking, DIY projects, home improvement and many more interesting topics here.