Jun 07, 2023

Ask Hackaday: What’s In Your Fastener Bin?

A Saturday afternoon. The work week was done, the household chores were wrapped up, and with almost a week left until Christmas, there was just enough wiggle room to deny that there was still a ton of work left to prepare for that event. It seemed like the perfect time to escape into the shop and knock out a quick project, one that has been on the back burner since at least March. I’m nothing if not skilled in the ways of procrastination.

This was to be a simple project — adding an aluminum plate to a plastic enclosure that would serve as an antenna entry point into my shack. Easy as pie — cut out an rectangle of aluminum, cut and drill a few holes, call it a day. Almost all of my projects start out that way, and almost every time I forget that pretty much every one of those builds goes off the rails at exactly the same point: when I realize that I don’t have the fasteners needed. That’s what happened with this build, which had been going swimmingly up to that point — no major screw-ups, no blood drawn. And so it was off to the hardware store I trundled, looking for the right fasteners to finish the job.

Finding hardware has long been where my productivity goes to die. Even though I live a stone’s throw from at least half a dozen stores, each with a vast selection of hardware and most open weekends and nights, the loss of momentum that results from changing from build-mode to procure-mode has historically been deadly to my projects. I’m sure I’m not the only one who has run into this issue, so the question is: what can a hacker do to prevent having to run out for just the right fasteners?

It’s pretty easy to spot the root cause of this problem with a stroll into pretty much any hardware store. Somewhere in the store will be an aisle lined with bins and drawers holding every conceivable kind of fastener. There’ll be everything from lag screws and carriage bolts for fastening together wooden structures to tiny packets of M3 screws that would be at home on a 3D-printer. Add to that the different thread pitches and styles, the range of diameters and lengths, the variety of materials and finishes, the wide range of drive types, and the confounding effect of different nuts, washers, lock washers, and other adornments, and you’ve got a nearly infinite number of combinations.

The other problem is that there’s really not that much leeway in making substitutions with fasteners. Each kind of fastener has a pretty specific engineering purpose, and in some cases, making a change to something that’s already on hand can be risky. I’ve learned this the hard way, and that fact alone is why I ended up wasting a bunch of time on a recent project to fit a cargo van with solar array. The van is going to carry six solar panels on mounts that fold down for travel; using the wrong fastener could result in a wind storm tearing the panels off, or worse yet, cause something to break off the trailer while it’s being towed down the highway. Avoiding such a fate was well worth a few extra trips to the store to get the fasteners right.

There’s one more factor that probably affects some more than others, and that’s aesthetics. Sometimes the fastener that you have on hand just doesn’t look very good. I recall looking for cap screws in Lowe’s, with my wife helping out in the search. When she announced that she’d found them, all I could say was, “I need socket head cap screws, but those are round head. Are you insane?” Sometimes it just has to look a certain way.

All this is to say that the universe of fastener choices far exceeds the means of the average hacker to reasonably keep on hand,although that hasn’t kept me from trying this brute-force approach to fixing the problem. Years ago I was offered a chance to buy outright the entire fastener display from a hardware store that was going out of business. The whole thing — the bins, the drawers, even the rolls of plastic bags for parts and the ballpoint pens on the little sproingy things that never manage to write the stock numbers on the bag — could have been mine for a price. It was a tempting offer, but as I had neither the means nor the space to store such a thing, I declined.

Had I actually picked it up, would it have solved the problem? Probably for a while, but I suspect I would have ended up with a lot of stuff I had little call for, and not enough of the good stuff. And what’s worse, my needs have shifted significantly. I was working a lot with wood back then, and only did the occasional metalworking project. There’s not a lot of crossover in the fastener needs of the two media, so switching away from a lot of woodworking would likely have stranded a lot of fasteners from that original allotment.

I think the closest I’ve ever come to seeing a solution to this was at the model shop in the place I worked for 23 years. It was a full machine shop to support scientific research, and the fellow who built it from the ground up really hated getting caught without hardware. He had two Lista cabinets each with a dozen or so drawers, and each drawer had a bunch of little plastic bins holding screws, nuts, and bolts. In the metric cabinet the fasteners ranged from M1 to probably M12 and running up to perhaps 50 mm in length. He limited materials to stainless and black oxide, and head style to either socket head or round head. The other cabinet contained the equivalent inch fasteners, and each cabinet contained nuts and washers. It was limited, but it was also comprehensive, and got him through perhaps 80% of his daily work without having to run out or place an order.

While most of us can’t afford such a solution, I think shooting for the Pareto distribution like my machinist pal is probably a good goal in addressing the problem. If I can keep on hand the fasteners needed to complete 80% of my projects without having to resupply, I’d be thrilled.

The question then becomes, what’s the mix of fasteners that best accomplishes that? And once I decide on a mix, what’s the best way to source them? MRO (maintenance, repair, and operations) suppliers like McMaster-Carr, Fastenal, and Grainger are widely available, but priced more for corporate customers than individuals. Still, is there a place for them in this solution? And how would one go about storing and organizing a fastener collection like this, and making sure it stays stocked as parts are used? We’d love to hear from anyone who has dealt with this problem, either in an industrial settings and in the home shop. Let us know what you think in the comments below.