I just watched a couple of videos on YouTube where a motor mechanic/machinist/welder/foundryman reconditioned a drill press spindle for a friend. The spindle had a Jacobs taper for mounting a chuck and just above the taper were some threads for a nut which would be used to force the chuck off. The threads were chowdered and the taper showed signs of a slipping chuck. The whole end of the spindle was machined down and welded up. A fresh taper was machined and new threads cut. This gentleman did a fine job. When the video got to making a new nut (for forcing off the chuck) I was left scratching my head. Though we did not see it, the original nut was surely a hex nut. The new nut was knurled with only four puny 6mm holes for a tommy bar. It was mentioned that when the gentleman's friend obtained a new chuck, it would be fit to perfection with some lapping compound. Sounds like solid workmanship. But what about the next guy?
How often have you removed a chuck from your drill press? That's what I thought. Unless it gets damaged, the chuck is never going to come off. Now imagine a new chuck lapped to a perfect fit. Think of the use a drill press receives. Imagine decades of that chuck being force ever tighter onto that spindle by the downward pressure of drilling. Throw in some condensation from being in an unheated garage or shed. The next person to remove that chuck is going to be really, really pissed there's only puny 6mm holes in that nut. There will be an attempt at using a tommy bar, there will be cursing, there will be the desperation of having to get that chuck off... I see a pipe wrench and hammer in the chuck and spindle's future. The current nut was ( in order) faced, turned, knurled, parted off, drilled, bored and threaded. After that, the nut was screwed onto the spindle, mounted in a square collet block, mounted in a milling vise, center of the part found, four 6mm holes drilled. The knurling and 6mm holes could have been skipped. The set up could have otherwise remained the same and at least two flats machined onto the nut. Give the next guy the ability to put an adjustable wrench on that nut and have a fighting chance.
No, I can't see the future. I've been the poor bastard trying to disassemble things like I've described. When something like an air dryer gets mounted in a wheel well and is hanging out in the elements and requires three M8x160mm bolts for mounting... A torx headed bolt is not the best choice. A steel bolt passing through an aluminum air dryer into an air tank made out of shitty steel leads to a LOT of corrosion. And you know damned well the factory isn't going to waste the time or money to put a little smear of anti-seize on those bolts.
A year or so after the truck's warranty period has ended the dryer will fail. You know, because nobody reads the fucking owner's manual. Especially the part about air dryer maintenance (change the cartridge every fall people). The dryer will inevitably fail somewhere on the road and it will fail so bad that the whole rig can't be limped into a shop. Some sorry-ass mechanic will end up out there to replace the air dryer. He will sized up the situation and see what tools he needs to... "Fucking torx heads? WTF! What fucking soft-handed desk jockey is responsible for this fuck up!! Yeah, sure, use torx heads because metal never fucking corrodes!!!" The mechanic will spray some panther piss on the thing knowing that it isn't going to help. He'll then put a torx bit onto a ratchet and gently try to loosen those bolts. The torx bit will break. The bit breaks because of many things. Mostly because the never work in high torque situations but other factors are involved. The recess in the bolt is too shallow because some bean counter didn't think an extra 5/10 of a cent was worth using a quality fastener, with a deep enough recess to allow good purchase of the bit in the fastener. A plain 'ol hex head bolt would, at least, allow the mechanic to gingerly work the fastener back and forth, giving him a small chance of success. But they didn't. The mechanic is now so pissed off the driver has become concerned about their safety. The mechanic grinds the bit down and tries again after putting a little heat into the parts. *SNAP* "FUCK!!!!!" The mechanic is now going to drill the heads off, remove the air dryer and use vise grips to get the bolts out. Oh, but wait. Where in the hell is he going to get M8x160mm bolts at 02:00 on a Sunday morning? The longest bolts at the shop are 60mm. "FUCK!!!" The mechanic then discovers that there's so much other crap in the way he'll never be able to get a drill in there. The situation just snowballs. But, for this case, let's say the mechanic called in some favors and managed to wake up a friend who had some M8 threaded rod. He has to go and get it, return to the broken vehicle, cut the rod, fit it, install the new air dryer and make sure it works. Great. It's all done and working. Looks like a redneck did the work but at least the truck can roll.
The bill is handed to the driver and he freaks the fuck out. The mechanic (already tired, very pissed off and very cold because it's January in Wisconsin) has to explain all of the labor time. Removal of shitty fasteners, the fastener supply situation, the retrieval of fasteners from far off corners of the county, billing by the hour (explained right at the first phone call but forgotten by the driver), the custom fitting... The driver ignores the fact they ignored dryer maintenance for years so the whole thing is their fault. The driver ignores the fact that the mechanic had to get out of bed in the wee hours on a cold January night and has been working in frigid temperatures for hours while he sits in a warm truck. Yeah, it's all the mechanic's fault. All mechanics are crooks (said with sarcasm).
It all comes down to shit design and cost cutting. I'm quite sure the person responsible for the air dryer design and mounting, while sitting in a clean, comfortable, climate controlled office, never once thought of what their choices would be like five years down the road. No, that fucker was never going to be dodging cars on the side of an icy interstate highway so why should he care? The bean counter doesn't care, he's only concerned with keeping costs down so the company profits remain high and many trucks will be sold. "Fuck service! Fuck mechanics! Make it good enough to get through the warranty period. Who cares after that?" It ends at the truck's sticker price. Trucks that are easily serviced and will last for millions of miles can be built. You wouldn't pay for it. The price for good design and workmanship would be so high that nobody would buy the trucks. Think of it in tool terms. You need a set of wrenches. The dollar store has a set of wrenches from 1/4" to 1" for $15. Snap-On sells a 1/4" to 1" set of wrenches for $600. Which set do you choose? If you chose the $15 set of wrenches, you're part of the problem. Sure, they'll work right now and may actually fit fasteners. They won't last long and you'll soon see why the wrench set was only $15. The Snap-On wrenches, though initially expensive, will fit properly, will feel good in the hand and will be built so good they'll outlast you, your children and your grandchildren. And they have a lifetime warranty.
You need to look to the future. As you install that exhaust manifold, put some anti-seize on the bolts. Think of the next guy who will have to take it apart. Those bolts will break loose, he'll see the silvery remains of anti-seize and he'll thank the mechanic who put those bolts in. That mechanic will do the same. It can go the other way of course. I once was involved in a starter replacement for a dump truck that was in the middle of a muddy field. The first guy spent two hours trying to get three starter bolts out and was only successful with one. I came in for the day and was sent out to finish the job. I had five hours into it and only got one more bolt out. I had to have the shop bring me bigger tools, I had to heat the shit out of the parts... The first guy went back the next day and finally got the last bolt out. You know what he found? Having been there while the sun was still providing good light, the first mechanic saw that some asshole had put green loctite (bearing retainer) on the bolt threads. Green!! What a dick! It's karma. Do something to be a little shit and it will come back to you. If you think taking the extra time will make things easier for the next guy, do it.