Cam out can be frustrating, and in worse cases can cause damage to the screw heads or even your screwdriver or driver bits. But the big question is what is cam out and how to avoid it?
Even though you might not be familiar with the expression “cam out”, great chances are that you’ve experienced this phenomenon at some point on the shop floor. Cam out happens when the tip of a tool such as a screwdriver dislodges from the screw drive when turning it.
Cam out is a common occurrence for both amateur and seasoned DIYers, and can lead to stripped screws, which can be daunting to remove. But the good news is that there are several ways to avoid cam out altogether, regardless of the screw type you’re using.
What Exactly is Cam Out?
Cam out is when a screwdriver tip slips out of the screw drive while rotating it whether to tighten or loosen the screw. Cam out can not only cause damage to the screw and the tool you’re working with, but can also cause injury, which is why it is best to avoid it as much as possible.
Cam out occurs when the turning power (torque) applied to the screwdriver causes its tip to be pushed upwards, and disengage from the screw’s head while turning it. Even though cam out can occur with any type of screw, this issue is common to conical screw profiles such as Phillips screws.
These types of screws feature a tapered cross recess towards the center, which are designed to accommodate the tapered tip of a screwdriver. Turning the screwdriver causes lateral force on the screw drive, consequently forcing its tip to be pushed outwards.
This can lead to several issues, most notably tool tip crushing, groove collapse, and damage to the cross recess. Camming out can occur with both manual screwdrivers, and powered drivers when lack of downforce is applied to engage the screw or you’re trying to drive the tool at an angle, resulting in the bit being pushed up and out.
What Causes Cam Out?
There are several factors that can lead to cam out, most notably:
Using softer screws of damaged screw bits – this is perhaps the biggest reason that can cause your screwdriver bit to slip and cam out. Brass screws or other types of soft screws are more susceptible to cam out, which is why it is a good idea to select the best tool for the application.
Be sure to check screwdriver bits before using them, because even the slightest defect could prevent a flush fit with the screw drive, and increase the chances or it slipping out, resulting in damage to the screw head.
Using the wrong screw for the application – as mentioned earlier, Phillips screws are most likely to cam out, especially if you’re using the wrong size bit for the respective screw drive size or if you need greater torque when working with more robust materials and larger fixings.
Applying less downward force – if you don’t apply enough force when inserting the bit into the screw, the bit is more than likely to pop up and out when rotating it, particularly when using Phillips screws.
Now using the tool at the right angle – to insert the screw right, the screwdriver tip should be flush with the screw head. The screwdriver head will in this case not get a good grip with the screw’s drive, which can increase the risk of it camming out. This happens more often when more turning power is applied.
Three Ways to Avoid Cam Out
One of the best ways to prevent cam out is to apply more downward pressure on the screwdriver. That said, here are three ways to avoid cam out.
1. Use the Correct Tool
The easiest way to prevent cam out is to use the right tool for the job. This doesn’t mean deciding whether to use a manual screwdriver or impact driver, but rather choose the right size screwdriver or the right screwdriver bit for the screw drive.
There are several ways to gauge whether you indeed have the right tool for the screw, but the easiest way is to insert the screwdriver in the screw driver, and ensure it sits flush and snuggly.
For example, if you’re dealing with a #2 Philips screw, you will to use a #2 Phillips driver, whereas #0 or #1 sized Phillips wood screw, you will need to use a #0-sized driver to ensure a snug fit, and hassle-free driving.
Another aspect that’s often overlooked is the condition of the screwdriver or screwdriver bit. This is why it makes sense to overlook poor quality tools, and choose the best one for your budget from the get-go.
Additionally, you should also examine the tool you’re about to use for any signs of wear and tear, because they can be less effective when put to the test.
2. Use the Right Screw
While you can buy the best screwdriver or powered screwdriver, it won’t work well if you have the wrong screw type. On a brighter note, there are myriad screw types to choose from, so for example you could use a hexagonal, star drive type that provides greater surface area and grip to reduce the chances of stripping.
As an alternative to Phillips screws, you could use Torx screws, as they don’t have a tapered recess, making them hard to cam out as long as the screwdriver is properly aligned with the screw.
3. Maintaining Balance and Alignment
Finally, it is extremely important to keep the screwdriver head properly aligned with the axis of the screw. The tip of the screw should be placed in position where it is vertical to the head of the screw, because even the slightest tilting can prevent a flush fit, and lead to cam out.
Cam out is basically when the screwdriver head slips out of the drive of the screw, while rotating it. Even though it can happen with any screw, Phillips screws are more inclined to cam out than others, owing to their tapered design and four corners.
Slotted or flathead screwdrivers aren’t used as much as they used to be, but are one of the least prone to cam out. Other types of screws that are less likely to cam out include Torx and hex compared to Phillips screws.
If you’re going to use Phillips screws, you can use an anti-cam out screwdriver to reduce the chances of slippage. All in all, cam out is inevitable when working with any type of screw, but the tips above should reduce the chances, and prevent injury.