Drill Bit vs Driver Bit: Key Differences

Drill bits and driver bits seem interchangeable to the uninitiated, but they’re not. What are their specific functions, and how do you choose between them?

Difference Between Drill Bits and Driver Bits

To the untrained eye, drill bits and driver bits seem interchangeable, but they’re not. Drill bits typically have a round shaft compatible with a cordless drill paired with a helix-shaped, or twist, cutting section. Driver bits have a hexagonal shaft compatible with an impact driver with a tip compatible with specific fasteners. Driver bits can also have a twist bit tip, but this isn’t as common since driver bits are generally used to drive screws, while drill bits are primarily used to drill holes.

This article focuses on the difference between drill bits and screwdriver bits used on cordless drills and impact drivers. Let’s outline the main differences.

Design & Construction

Drill bits typically have a round shank that fits into a drill chuck.
Driver bits have a hexagonal shaft – this is essential for compatibility with impact drivers. Driver bits also have a tip compatible with the fasteners they’re meant to drive. It’s essential to match the bit size with the fastener size to effectively operate and prevent the bit from slipping.

Then there is also hex shank drill bit which has a hexagonal shank similar to driver bits, but the rest of the body is similar to a twist bit and can be used to drill holes. But this isn’t as common since the impact drivers is mainly used for driving fasteners, not drilling holes although you can use it for drilling.

Purpose

As the name suggests, a driver bit will be used mainly to drive screws, and drill bits is for creating new holes or enlarging existing holes..

Impact drivers typically carry out harder work than drills. While both can drill holes and sink and remove screws, impact drivers provide an impact force that makes quick work of this action. That’s why they’re used to sink long screws and larger bolts, like lug bolts, and for repetitive work on large projects, like decking installation.

In comparison, cordless drills do lighter work. They’re also better suited to working on lighter materials, where the impact driver might damage more delicate materials. Drills are mainly used to drill holes and, to drive screws into soft material. Drills are meant for light work around the home and in DIY projects, while impact drivers are the handyman’s friend on tough jobs.

Torque

Driver bits typically experience more torque and greater impact during operation than drill bits. For this reason, they’re far tougher than regular twist drill bits. They can withstand more torque and have greater impact resistance.

Non-impact bits should never be used on an impact driver since they’re not designed to handle that kind of stress. As a result, they’re likely to break or shatter during operation, potentially causing harm to the operator and damage to the workpiece.

Hardness and Toughness

A regular twist drill has uniform hardness throughout the body of the bit which enables you to re-sharpen and reuse the bit.

The driver bit undergoes special heat treatment process to improve the toughness. Like I explained in the previous section, driver bits need to withstand the impact force delivered by the hammer mechanism inside the impact driver. The achieve this by keeping the inner core of the driver bit softer than the outside.

You can use impact bits in a regular drill, but you should not use regular screw driver bits in an impact driver.

Speed

Drills typically work at a higher speed than driver bits. For this reason, twist drill bits are often made to be more friction-resistant, thus decreasing heat build-up during operation. This reduced friction is a bonus when drilling deep holes in tough material and many holes in short succession.
Since driver bits typically don’t experience friction during operation, other than at the point of contact with the fastener, they don’t need friction resistance.

High-speed operation enables drill bits to cut through material quickly. You also need varying speeds depending on the diameter of the drill bit as smaller diameters require higher speeds. Driver bits don’t need to work as fast since driving a fastener isn’t as speed-sensitive.

Cost

Driver bits tend to be more expensive than regular drill bits. A few factors influence this pricing gap. First, impact drivers are tougher than drill bits and thus require more advanced manufacturing techniques and more expensive raw materials. There are exceptions among drill bits, where high-performance drill bits such carbide and cobalt bits are costly.

Then, there’s the versatility and specialty. You can use the same twist drill bit do drill different materials such as wood, plastic, metal etc., but limited to a single diameter (unless you are using step drill bits). Driver bits are less versatile since the driver must be matched to the fastener slot. This means that you need a wider range of driver bits in your arsenal than you would drill bits.

Of course, you can use a Philips driver bit for a range of screw sizes, but for Torx drive, hex, Robertson square drive, etc., you will need dedicated driver bits for each size.

Then, there are specialty driver bits such as the Triple Square and Poly-drives specifically used in the automotive and aerospace industries. Specialty bits are costly, and these fasteners are typically not compatible with other drivers, leaving you with little choice but to shell out the money for a set.

Advantages of Using Drill and Driver Bits on Impact Driver

Impact drills work similarly to power drills but have a few marked advantages.

Quick Changing between bits

Impact drivers typically have a quick-release mechanism compatible with all ¾” hexagonal shanks. This makes changing bits extremely fast compared to drills.

The hex socket provides a better grip than the 3 jaw chucks found on cordless drills.

Hex sockets offer a far superior grip than the three-jaw chuck typical in cordless drills. This ensures that the shank is aligned easily and that the bit is less likely to slip in the shank.

Higher torque of impact drivers

Impact drivers offer far higher torque than cordless drills. This torque is offered in an “impact” sequence, where the drill bit works in short bursts at 50 times per second. Additionally, they turn bits in a two-step-forward-one-step-back pattern, which allows for far more effective driver engagement.
Practically, the driver bit is less likely to slip during operation.

Advantages of Using Driver Bits on Cordless Drills

Driver bits can also be used in cordless drills. They operate without impact functionality, making them better suited to lighter work.

Better Torque Control

Cordless drills have a clutch, which stops the bit when reaching maximum torque. This torque control makes it less likely to strip fasteners or slip out during operation. Torque control is a safe option, specifically when working with more delicate materials, like PVC and other household plastics.

Higher Speeds for Drilling

Cordless drills operate at far higher speeds than impact drivers. This means the fasteners will be installed or removed faster than when using a driver bit. While this won’t make much of a difference on the average DIY project, it could shave hours off large installations with a large number of fasteners.

Versatile Tool

Cordless drills are versatile and can be used in far more applications than impact drivers. Adding driver bits to your toolkit enhances the versatility of this workshop staple.

Conclusion

Driver bits and drill bits aren’t interchangeable. Driver bits are meant for driving fasteners, while drill bits are meant for drilling holes. Both of these have specific advantages, and the one you choose depends on the job at hand.