What's The Difference? Hammer Drill VS Impact, 10.8-volt VS 12V Max
The world of tools is filled with lots of questions and confusions, which are sometimes magnified by tool manufacturers and their fancy way of using words to try and sell you something. These confusions can be hard for the consumer who just wants to buy the right tool. So, in order to clear up some of these questions, I thought I would answer some of the most common questions I receive.
What's the difference between a hammer drill and an impact driver?
This is a very popular question, and although these two tools sound like they do the same thing, they are very very different.
A hammer drill is a drill with a downward hammering action. It is designed to drill small diameter holes into concrete, brick, stone, etc. The easiest way to explain a hammer drill is to visualize a person drilling a hole with one hand, while hitting the back of the drill with a hammer at the same time. Or think of a jackhammer, with the addition of a spinning. The hammer action breaks up the material that is being drilled. A rotary hammer acts the same as a hammer drill, but is much larger and can be used to drill larger holes. Besides size, a hammer drill still uses a typical drill chuck, while a rotary hammer uses a specialty chuck and matching bits.
An impact driver or impact wrench uses impacts in a spinning direction. Impacts are all about adding more torque to your screwing or unscrewing needs. Using an analogy like above, think of a man using a wrench on a bolt, and using a mallet to hit the wrench to add more spinning torque. Impacts come in all kinds of shapes and sizes – cordless, corded, and even pneumatic. The way impacts are designed, they can offer insanely-high amounts of torque, with almost no strain or feedback felt by the user.
What is the difference between 10.8-volt and 12V Max cordless tools?
This is also a popular question, and can be blamed on brand marketing.
10.8-volt and 12-volt Max lithium-ion batteries are exactly the same, there is no difference at all. When the first of these ultra compact tools came out, they were all correctly called 10.8-volts. The number comes from the amount of cells in the battery, multiplied by the cell voltage. The 12-volt thing started when one of the manufacturers came out with their ultra compact line of tools and used the battery pack's peak voltage in their marketing. The peak voltage is the amount of volts the battery has after a charge; this voltage quickly drops to the actual voltage where it remains during normal battery use. These 10.8V batteries are called 12V Max, and are not the same as actual 12-volt batteries.
Instead of falling for this marketing trick, look at the Ah of the batteries to see if there is any edge. The higher the Ah the longer the battery will run. Bosch recently introduced 1.5Ah 10.8V batteries, while the typical Ah rating for a 10.8V battery is 1.2 Ah.
What is the difference between 18-volt and 20V Max cordless tools?
Same Song, Second Verse.
This is the same thing as with 10.8/12v batteries. Sticking with their same marketing tactics and as a way for them to differentiate from their older style batteries, DeWalt chose to call their new line of 18-volt tools, 20V Max. Again, there is no difference in actual battery voltage. As above, one thing to watch out for is the Ah rating on the batteries. Thinner 18V batteries are thinner because they are better made, they are thinner because they offer less Ah.
Makita for example sells 1.5Ah and 3.0Ah 18-volt lithium-ion batteries. For some reason Makita made it so their White (consumer) line of tools can use both sizes of batteries, but their Green (Professional) line of tools can only use the large batteries.
Bosch also had two battery pack sizes, but they were rated at 1.3Ah and 2.6Ah. Bosch just recently came out with new HC (high capacity) batteries that are 1.5Ah and 3.0Ah and also feature a built in fuel gauge. The old batteries are still on the market, so be sure to pay attention to the "HC" label on the newer batteries.