Nuts and Bolts

As a kid, it was always a joy of a treasure hunt to rifle through the nuts and bolts bins in dad's garage. In my mind I could assemble almost anything my imagination dreamed up, so long as whatever materials I mustered had holes in them. Dad didn't give me rights to the power drill right away and when he did, I am sure he regretted it. I was and I am very hard on drills. In the course of rummaging through the bolt bins, I also became acquainted with nuts and washers, which are very important to the efficacy of bolts in the process of fastening things. Dad also had screws, which were just as useful, especially when working with wood, but there are differences between bolts and screws, and I will use the definition supplied by wikipedia here to show the differences:

A bolt is an externally threaded fastener designed for insertion through holes in assembled parts, and is normally intended to be tightened or released by torquing a nut. A screw is an externally threaded fastener capable of being inserted into holes in assembled parts, of mating with a preformed internal thread or forming its own thread, and of being tightened or released by torquing the head. An externally threaded fastener which is prevented from being turned during assembly and which can be tightened or released only by torquing a nut is a bolt. (Example: round head bolts, track bolts, plow bolts.) An externally threaded fastener that has thread form which prohibits assembly with a nut having a straight thread of multiple pitch length is a screw. (Example: wood screws, tapping screws.)

As you can see, there is a difference between a screw and a bolt. As a child, I was fascinated by the markings on the tops of the bolts. If you look at the illustration to the right, you can see the different grades of bolts, which refer to the strength of the bolt.

Plain bolts are called grade 2 bolts. These can be 1/4" through 1.5" in diameter and are made from low to medium carbon steel. Minimum tensile strength can be from 60,000-74,000 psi.  That sounds like a lot, but if you use these bolts in place of grade 5 or 8 bolts and torque them a bit too much, you'll find out rather quickly how substandard they are for the job. Luckily they are also the softest of bolts and are easier to drill and use an easy out to remove. If you've ever tried to drill a grade 8 bolt that seems hardened, it can be a chore, if not impossible, trust me.

Up from Grade 2 bolts are Grade 5 and Grade 8. Grade 5 bolts are 105,000-120,000 psi is tensile strength, again depending on the diameter. Diameters under 1" are stronger than those over 1" Grade 8 bolts have a tensile strength of 150,000 psi. The king though are metric bolts with a designation of 12.8, which have a tensile strength of  about 175,000 psi. What is tensile strength? I am glad you asked.

According to the Bolt Depot, tensile strength is "the maximum load in tension (pulling apart) which a material can withstand before breaking or fracturing". Grade 8 bolts are used in high stress places like main bearing caps, head bolts of yore (head bolts are a subject unto themselves), and suspension parts, to name but a few. Use bolts of lesser grade and quality and the least worst that could happen is that you are stranded. The absolute worse is loss of control of a vehicle due to a breakage in a control mechanism. Not good. If you work on cars, make sure you use the correct fastener for the intended purpose. End of lecture.

Mark Zimmerman, my inspiration.

Back to Dad's Garage. I have no idea where dad got these bolts, screws and nuts. I don't think he was a collector and he wasn't a car nut. Dad was more into wood, like Norm Abrams, whereas I was/am, more of a Sam Memmolo or Mark Zimmerman, both of whom I hold in very high esteem (I am surely delusional in making that statement as I couldn't carry their jocks). It must run in the blood though, my uncle Carmine, AKA Uncle Cam,  was an auto mechanic for 38 years at Mack Markowitz Oldsmobile and his son Robert or Bobby is chair of the Automotive Technology program at SUNY Farmingdale for many years. May be I just had a lot of incentive. Who knows. I do you know I learned a lot of from them, and others like like Don Ness, Don Seals, Freddy Schenck, Chris Modugno and Phil Saccio. Always listen well to those that know their way around a car or anything else for that matter.

Anyway, Dad's garage was a treasure trove for after school missions into mechanical glory or just futzing around. I miss those days of exploration and just total immersion into nothing special. There's nothing better than a day spent letting your mind and hands work together to create something from your will or just getting lost in that process. It surely beats a day at work, no? Or am I just nuts?

Thank you for reading this blog.