One of my goals in writing this article is to address the great questions that have bewildered the handyman (or woman) for decades. For example, last week we looked at the names of sizes of nails. This week we attack another great controversial question: What is the difference between a bolt and a screw?
Okay, all you machinists, mechanics, carpenters and anyone else who may use fasteners, take a moment and think about it before you read the rest of this column. Thinking...thinking...thinking.... please proceed.
Is it the head or type of drive? Bolts, generally, have a hex head and are tightened with a wrench. But what about lag screws? They have a hex head.
Do all screws have “pointy” ends? Machine screws have blunt ends and threads like a bolt.
Is it the thread count? Screws and bolts come in a variety of thread patterns from fine to standard to metric and on and on.
Here is the best answer that I can find, nuts.
Bolts are generally designed to go through two or more pieces of material and fasten with a nut on the other side. Screws are designed to thread into pre-made threads, or cut their own threads, to fasten material together without protruding from the other side.
Wait, wait, wait.....what about machine screws that can be fitted with a nut? Yeah, that’s what I said. It seems that machine screws are manufactured with the purpose of threading into “pre-threaded” holes and holding material together without the use of a nut. Therefore, it is technically a screw. Maybe if you get it long enough to go through and put a nut on it, it becomes a bolt. Maybe...
Anyway, that’s the best I can explain it. I hope you sleep a little better tonight now that this is cleared up. Remember, help is just around the corner at your local hardware store.
