The history of the bolt

Bolted - A FORUM ABOUT OPTIMIZING BOLT SECURING ^ | 20 December 2017 | Allanah Eames

[DaxtonBrown]

I buy a lo of bolts restoring my classic cars and building a 3d printer. A lot of stainless steel, abd Grade 8. I’ve had to learn a lot.

[Robert A Cook PE]

Did not expect to read this today. Thank you for the time.

[minnesota_bound]

Frank 'bolts'

[OftheOhio]

Thanks. My greatest accomplishment as an engineering designer over the years was screwing metric over every chance I got, lol. Back in 2008 I got a batch of mil spec bolts that were obviously Chinese counterfeit. It would do well in industry to start testing some of the received hardware. Same with drill bits that are made today, utter trash. I had a pack of Dad’s drill bits from the fifties that would cut through steel like butter. Nuts, Bolts, Fastening, and Joining made American industry what it was in the past.

[Vendome]

This thread is nuts...

[OftheOhio]

Speaking of drill bits for making bolt holes, my mind was totally blown when I was introduced to rotacut drill bits.
http://www.hougen.com/cutters/sheet-metal-hole-cutters/Rotacut-sheet-metal-hole-cutters.html

[eastforker]

They are. Next time look at the markings on the head of the bolt for hardness.

[BikerTrash]

bfl

[reed13k]

interesting thread. Few years back we had an issue with bolts breaking under a high G application.

Turned out it was due to the heat treat process. 1st issue is the standard wasn’t followed - preheat, heat treat, post heat. But even worse the standard was developed for sheet and rods but not threads.

There was a proposed standard in development that we implemented and ended up helping to validate but even then we had to test every lot. Huge disruption.

They had had similar issues years before then it just went away - in the end it had to do with minor metallurgical differences (all in spec) combined with a poor standard that wasn’t applicable to the application.

So glad to be away from that.

[gigster]

I’ve been a Machinist for over forty years and this is the first time I’ve seen these facts. Good article.

[untenured]

More obvious inventions like the cell phone and the airplane get all the attention, but human progress also depends on mundane, often-anonymous examples like this. Corrective lenses (late medieval Italy) are another one.

[Does so]

Thanks for posting this. Thirty years ago, I bought several hundred stainless steel 4" lag bolts. They went to build a long dock. When the dock got scrapped by the new owner (an old neighbor), I had him save the bolts. They've since been used again and again in retirement projects. When necessary, I've cut them down to 3".

Curiosity #1: At a yard sale, I bought a pile of aluminum nuts/bolts with a shaft diameter of ⅝-inch. What engineering could possibly need something so big, yet so "unstrong"?

Curiosity #2: I also stumbled onto 100 stainless-appearing lag bolts of ¼-inch diameter, which eventually rusted to light "rusty-patina"—but got no worse in a severe saltwater environment. They had a head stamp of 2 straight lines at right angles.

‽

[BBell]

LOL!

[BBell]

That’s funny.

[Jimmy Valentine]

Very interesting. We had problems here in the 1970s with counterfeit bolts coming in from Asia.

[meatloaf]

How does the average man on the street buy good hardware and avoid junk. I’ve heard that Fastenal makes their own. Are there brands that can be trusted.

[Squantos]

Pretty sure I’ve seen every kind of counterfeit grade 8’s made at some point ....... nice chart btw ...... funny stuff. Might try to make some of those for fun.

[central_va]

What are the nuts and bolts of this story? Screw it.

[reed13k]

Not that I’ve found - we had to go and qualify all ours and make sure the processes were up to spec.

At home I basically go with the highest grade I can find in the size I need and over compensate. Still no guarantee and I’ve had a lot of heads pop off usually due to bad heat treat or plating.

[alfa6]

Thanks

Regards

alfa6 ;>}