There are some who seem to be confused by all the different terminology surrounding power drills. Some of the common question we have been asked over the years are:
- What does VSR mean?
- What is the difference between SDS and spline drive?
- How does chuck size matter?
- What is the difference between keyed and keyless chucks?
- What is a hex driver?
- Should I go with a cordless or corded drill?
- What type of cordless battery is best?
- What is the clutch used for?
In order to answer some of these questions, we have put together this list of questions and answers that we hope will be found to be informative and helpful.
What does VSR mean?
VSR stands for variable speed reversible. Drills with this feature are able to operate in both forward and reverse rotation and at variable speeds. Most likely the drill will have a switch or button for switching the rotation from forward to reverse. Generally the speed varies in relation to to how far the trigger is pulled.
What is the difference between SDS and spline drive?
SDS and spline drive refer to two types of bit technology used in rotary hammer drills. There is really no difference in the performance of the two types, so the one you choose will simply be a matter of which type your particular rotary hammer drill requires. There are different sizes of SDS bits which include SDS, SDS+, and SDSmax. Smaller rotary hammer drills will use SDS or SDS+ bits where the larger rotary hammer drills will use SDSmax or spline drive bits. As the name implies, spline drive bits have a splined shaft, while SDS bits have concave recesses in the shaft.
Why does chuck size matter?
Chuck size basically determines what size drill bit you can use based on the size of the drill bit shank. With the exception of rotary hammer drills and impact drivers/wrenches which use a special type of chuck, most typical hand held drills come with either a 3/8" or 1/2" chuck. Most of your smaller drills will use a 3/8" chuck, which will accept bits with shank sizes up 3/8". The heavy-duty models typically use a 1/2" chuck which accepts bits with shanks up to 1/2" in size. You cannot put a drill bit with a 1/2" shank in a 3/8" chuck, but you can put a bit with a 3/8" shank in a 1/2" chuck.
What is the difference between keyed and keyless chucks?
Years ago, all hand held drills used keyed chucks. In order to tighten the chuck down on the drill bit, you would use a small tool called a chuck key. Most 3/8" chucks and many 1/2" chucks today are now of the keyless variety. Keyless chucks, as the name implies, do not use a chuck key. Instead the chuck is designed so that a person can easily tighten the chuck down on the bit by hand. While keyless chucks are faster and easier to use, they cannot clamp down onto the bit as tight and therefore do not have the same holding power as a keyed chuck. This lack of holding power can potentially cause round shank bits to slip in the chuck. This is why you will still find many heavy-duty high torque drills using keyed chucks.
What is a hex driver?
A hex driver is just another name for an impact driver. Hex refers to the type of bit holder the drill uses. These drills use a hex shank bit designed not to slip in the holder. This type of bit holder also makes changing bits a snap. Impact wrenches, on the other hand use a square drive for accepting either 3/8" or 1/2" drive sockets.
Should I go with a cordless or corded drill?
This can be a difficult decision for some. The industry trend is ever going more and more towards cordless technology. The very first cordless drills on the market left much to be desired in both power and run time. Over the years cordless technology improved to the point where many cordless tools now compete with and even in many cases out perform their corded counterparts. With power and performance becoming near equal, the choice basically comes down to price. Are you willing to save some money and deal with the inconveniences of dragging power cords around, or would you rather spend a little more and have complete freedom of movement? The choice is yours.
What type of cordless battery is best?
The power tool industry is currently trending toward lithium-ion battery technology. With all the benefits of lithium-ion it is easy to see why. If you compare lithium-ion batteries to nickel cadmium batteries, lithium-ion charges faster, runs longer, maintains longer constant power output, weighs less and stores a charge longer. The disadvantage is that Lithium-ion costs more. However, the difference in price may not outweigh the advantages you get in performance and charge holding time. Having said that, not all lithium-ion batteries are created equal. There are many cheap off brands out there trying to pass off inferior lithium-ion batteries so shop carefully. Many of these may not even perform as well as a quality ni-cad battery.
What is the clutch used for?
Most drill/drivers and hammer drills have an adjustable clutch. The clutch is typically used when driving screws, nuts, or lag bolts. The clutch is designed so that once a certain required amount of torque is reached, the clutch will engage and cause the rotation of the chuck to slip and stop rotating. There are several reasons for this. One, you won't strip the screw head when the bit keeps turning. Two, you won't drive the screw too deep. Three, reaction torque when the screw or nut bottoms out won't twist your wrist. Many drills produce enough reaction torque to cause bodily harm if the clutch is not used. Many heavy-duty drills capable of producing high amounts of reaction torque have either a non-adjustable built in clutch or a built in torque limiter. And finally, the clutch protects the drill motor from damage.
The Tool Spot would like to thank you for reading our free article. If you enjoyed this article and would like more information please visit our web site where we specialize in selling the best rated power tools such as this top rated 18V hammer drill and this top rated 18V cordless circular saw.
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