Basic Tools: Screwdrivers

The screwdriver is probably the most basic tool and even folks who don’t own tools own a screwdriver or two.    When you think of screwdrivers you probably think of a Phillips or slotted drive screwdriver.  Even with these two standbys there are multiple sizes.   These days there are a couple of other designs making their way into the lives of ordinary folks.  In this post I’ll talk about about some of the different screwdriver tip designs, sizes, and things which are not quite screwdrivers.

So, lets take a look at a bunch of screwdrivers.  As you can see they come in various sizes, shapes, and even colors.

Tip Designs

The most basic screwdriver tip is the slotted or flathead design.  It’s the simplest design to make because it just requires a slot.  This also explains why it is the oldest design.  The downside to the slotted design is that the screwdriver can slip out of the size and the head of the screw can be stripped pretty easily.  Using the correct sized tip goes a long way towards keeping the screw in good shape.

Here’s the next most frequent screw design: the Phillips.  Named after the guy who invented the design, it is easily recognized by it’s “+” shape.  This design was initially popular with industry because it was self centering and would cam out (let the bit slip out) before stripping the fastener.  Unfortunately, this caming out feature also can make them a bear to remove when the screw is stuck.  A more recent improvement, known as ACR (Anti Cam Out Ribs), on the Phillips tip contains small ridges to increase grip.  Below is a picture of a regular Phillips tip.

Another design which is making its way into households and has been in use in industry for a while is the Torx.  The Torx design has six lobes and is specifically designed not to cam out.  As a result you can drive a torx screw straight through a piece of wood or put high torque on a bolt.  As it relates to the home, you might see this design most frequently on deck screws.

This next design, which is quite old, uses a simple square which it is named after but it is more formally known as Roberston Drive.   Early legal issues limited its adoption but you may still occasionally see some.

The last design I’ll cover is the hex or Allen.  This is another design that has been around for a while and is often seen on machines in the house or with furniture you assemble.

Tip Sizes

Screwdriver tips can come in a variety of sizes for each design.  The picture below shows a couple of different sized Phillips ranging from 0 to 3.  Phillips are numbered increasingly according to their size.

As you might have suspected, the different sized screwdriver tips fit in screws with different sized holes.  The picture below shows a number 2 and 3 tipped Phillips with their corresponding screws.

When trying to find the right Phillips screwdriver for your screw it is important to note that the tip does not fully sink into the recess in the screw.  The screw should only come about halfway up the angled part of the tip.  Using the correct sized screwdriver will help prevent stripping the screw out making life much easier.  A screwdriver too small will fit but won’t be tight.  When in doubt try a larger screwdriver size than you think is necessary.  If you’re wrong then driver won’t fit at all and you’ll know you need to use the next size down.

Picking the correct Torx bit is more challenging than with the Phillips design. The smaller Torx bits don’t change much in overall size but choosing the wrong size will easily strip the screw.  In the picture below I have the CORRECT sized Torx in the screw.

Compare the above pic to the one below where I have the WRONG sized Torx in the screw.  Not a big difference and you looking at it much larger than it is in person.  It looks like it fits, and will even turn the screw, but when more heavily loaded it will slip quickly ruining the screw.


The other end of the screwdriver also can have different variations.  Handles can be wooden, metal, rubber, plastic, or a combination of material.  The picture blow shows a plain plastic handle and an ergonomically shaped plastic handle with rubber inserts for grip.  I’m sure it is readily apparent which one is easier on your hands and allow more torque to be easily generated.

While not quite a screwdriver, the T handle hex driver shown below functions similarly.  The handles allow for increased torque to be applied to the fastener over a regular screwdriver or hex key.

A variation on the standard screwdriver is one with interchangeable tips.  The handle has a hex recessed into the shaft allowing you to swap tips for whatever the situation calls for.  Usually the shafts are magnetized to hold the bit.  In the picture below, a slotted tip is shown.

A fancier version of the screwdriver with swappable tips is this Kobalt Double Drive.  The handle on this screwdriver contains a planetary gear that allows the handle to ratchet when the handle is rotated or, if the blue ring is held fixed while the handle is twisted, will rotate the tip in the same direction when the handle is turned either direction.  In the days of battery powered drills it may be a solution in search of a problem but it is still a neat design.

Need bits for your screwdriver with swappable tips?  No fear.  They have them in pretty much every design you want.

Yes, they even make screwdriver bits that fit on ratchets.  I don’t have any slotted, Phillips, or Square sockets but I have use for hex and Torx designs when working on cars.  Compared to a simple screwdriver, a ratchet or breaker bar can generate a lot more torque.

Uncooperative Screws

Lastly, what do you do when that screw is really really stuck?  Hit it with a hammer of course.  This can be done in two ways.  Shown below is an impact driver.  You pick the appropriate bit to insert into the tip of the tool, hold it in the screw, and then hit the chromed cap on the end with a hammer.  The hammer blow forces the tip down into the screw while a mechanism in the handle also rotates the tip.  These tend to get the job done.

What if you don’t have an impact driver for your stuck screw?  No worries you can still make use of a hammer.  Take your screwdriver and put it in the stuck screw.  Rotate the screwdriver some but not so much that is jumps out of the screw.  Then hit the top of the screwdriver with your hammer over and over again.  The size of the screw and screwdriver determines whether you’re lightly tapping or mercilessly pounding on the end of the screwdriver.  This technique can save you in a bind.


So, there you go, a brief review of one of the most basic tools.  As with every other tool, quality matters and having the right tool makes the job much easier.  So, before you go strip that next screw and waste a couple of hours, get the right sized screwdriver to get the job done!

This entry was posted in Tools. Bookmark the permalink.

One Response to Basic Tools: Screwdrivers

  1. Clark says:

    Having a quality Torx screwdriver really makes a difference when it comes to using one on a Torx screw. Small things like how the tip was cut, the hardness of the tip and blade, and ergonomics of the handle matter. A soft tip will ruin the screwdriver and screw. I noticed the Wiha’s. The Germans make some very nice tools. A buyer’s guide at is helpful for finding the right Torx screwdriver for any job you may encounter.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s