Pan head machine screws are used in a specific way- ideally to join metal to metal or wood to metal in rarer instances. If you are just scrounging around in your tool box or in the bottom of a drawer for a screw to make a simple repair, you probably do not care about the names or types of screws and what sets them apart, but in certain situations you may need to know the exact type of screw so that you are using the right one for the right situation.
Sharp or Blunt at the End?
Some screws are sharp, allowing you to pierce wood with them as you screw them in. Some screws are not sharp because they are used to join metal, which has a hole already drilled into it. The machine screw is blunt on the end because it is designed to be used where there is a tapped hole already in place.
Choosing the Right Length of the Screw
The screw that you are using has to be long enough to go completely through the two pieces that you are joining together. In the case of the machine screw, they have to be long enough to also add a nut at the end. The nut keeps the screw from moving or being worked loose, which is important in the case of machinery that may have a high rate of speed or vibration.
The more movement, the more likely the screw is to work loose. In some applications, the required size of the screw will be listed, but that is not always the case. Before you start a project, it is important to know the likely sizes that you need and to have a few other options just in case.
The Type of Head of the Screw
When you mention the type of head of a screw, there are two things you are talking about. First, does the screw lay flat on the surface, does it stick up a little or is it meant to be turned in flush with the surface completely?
A pan head screw is one that is flat on the top but rounded on the sides. In addition, there is another thing to consider. A slotted head screw has a single line so it is meant to be screwed in with a straight screwdriver. A Philip’s head screwdriver has two crossed lines and is meant to be screwed in with a Philip’s head screwdriver. Some people claim there is no difference between the two, while others favor one over the other. Regardless, there are pan head machine screws made of virtually all lengths and with both slotted or Philip’s head heads for a number of uses. 3/8 in to mm