The phrase “pound per square inch” (PSI) has been thrown around a lot recently on the news and in the media, usually attached to one specific controversial figure – Tom Brady. So what are “pounds per square inch?” What exactly do they have to do with footballs? Why does this term seem so familiar? What is everyone even talking about?
“Pounds per square inch,” is a unit of pressure or stress. No, not that kind of stress. We don’t measure the stress from writing a term paper or getting a project done for work in terms of PSI. That is measured more in terms of hair loss. Rather, this is physical stress, the result of a force pushing against something. Most recently, we have been talking about the force of air pushing against the inside of a football. The NFL has very specific standards for the inflation of their footballs. They must be inflated to a pressure between 12.5 to 13.5 PSI.
The PSI affects how hard the football is. The higher the PSI the more firm the football. The lower the PSI the softer the football. The NFL has standards for PSI to ensure no team gains a competitive advantage. Every football should feel the same.
So I know I have heard this term PSI before. Where exactly did I hear about this? Probably in relation to your car tires. Like NFL footballs, car tires are supposed to be inflated to a specific PSI. This is all up to you to manage. Makes you feel like an NFL quarterback now doesn’t it? Well maybe it’s not that glamorous. Keeping your tires inflated to the proper PSI prevents them from becoming too soft or too hard. This keeps you safe (fewer blowouts) and keeps your car running efficiently (better MPG)! It may not be NFL football, but that sounds important to me!