When does a screw become a bolt?

[rgranger]

Sailors seem to be folk that get hung up on using the correct terms. i.e., lines, sheets, halyard, rode, block etc. So here is one more example,… and if I’m being honest, this post has no actual value… it is just an exercise in persnickering.


There was a recent post where someone asked about finding a particular "machine screw" long enough to through fasten with a nut.

Although it is common to use screw and bolt interchangeably, and in some cases the more common phrase is incorrect (i.e., lag bolt), a threaded rod that protrudes through the fastened materials and requires a nut to hold, is a bolt. Bolts often use a washer behind the nut… and a threaded rod that relies on the friction between the threads and the matted material to hold, is a screw.


In some cases, it is truly ambiguous. For example, it was common for Hunter to embed aluminum plates in the fiberglass of the hull and deck and then tap and dye those when machine “screws” were passed into them. The stanchion posts and deck organizers on my Hunter 26’ were secured this way. The aluminum plate served as an internal “nut” but technically since the bolt did not pass through the material and the deck hardware was secured by friction between the threads of the rod and the deck material, those fasteners were screws.

My coffee is getting cold so I think I should stop...

 

[BigEasy]

Sailors seem to be folk that get hung up on using the correct terms. i.e.,Although it is common to use screw and bolt interchangeably, a threaded rod that protrudes through the fastened materials and requires a nut to hold, is a bolt. Bolts often use a washer behind the nut… and a threaded rod that relies on the friction between the threads and the matted material to hold, is a screw.

Now you have really opened a can of worms; this thread could go into eternity! But, IMHO, I think you have it right as defined above.
Definitely an exercise in persnickering!!

 

[garymalmgren]

A set screw is a bolt with the thread going all the way to the hex head.

A cap screw is a bolt with a recessed hex head to take an Allen Key.

Therefore a bolt and a screw can be almost the same thing.
Don't sweat it. Or just screw it.

gary

 

[sailme88]

Nuts and bolts, nuts and bolts...we got screwed.... This was a HS chant 50 years ago when a believed an officiating error was made in a sporting contest...

 

[Leeward Rail]

If the fastener is strong then it's a bolt... If it is prone to failure.. then yer screwed ?

 

[Scott T-Bird]

Easy ... screws are fastened with either a flathead screwdriver or a phillips screwdriver. Everything else are bolts. A screw can have a pointy end or a machined end to be secured by nuts, so the fastener isn't important. I think, generally, screws are less than 3/8" diameter. Bolts are larger, but they can be smaller, too, if they have a hex head or an Allen head.

 

[rgranger]

Bolts are larger, …

So what I hear you saying is …size matters if you’re getting screwed

 

[Leeward Rail]

Easy ... screws are fastened with either a flathead screwdriver or a phillips screwdriver.

What about fasteners installed with torx, Robertson, and other screwdrivers ?

What if you use a drill driver to install the Phillips screws, instead of using a screw driver ? Does that make the fasteners, drills instead of screws ?

 

[Siamese]

When her husband comes home and you bolt out the window?

 

[MikeHoncho]

Bolts have pre machines matched receptacles (threads) . Screw do not and force their own .hence the term “ getting screwed”

 

[jviss]

So, the greatest newspaper headline of all time. I think it was the NY Daily News, or NY Post, or some such tabloid.

This criminally insane guy was being transferred from one prison to another, and in the process managed to run away. While on the loose he broke into a house and raped a woman. The headline:

Nut Bolts, Screws

​

 

[Leeward Rail]

Bolts have pre machines matched receptacles (threads) . Screw do not and force their own .hence the term “ getting screwed”

What about machine screws ? They have threads and matching threaded receptacles.

screwing often involves matched receptacles. Forcing their own is a different term altogether. "Epsteined" I think.

 

[dlochner]

Right about now I'm thinking there's a few screws loose here.

 

[Leeward Rail]

Right about now I'm thinking there's a few screws loose here.

Humor and psychoanalysis in one thread.

 

[Kings Gambit]

If sailors are hung up on using correct terms, it’s so we can talk to each other when working a boat or ship. To a crew, “please fetch my hand-held VHF radio.” “Where is it?” “Below at the nav station, outboard side; there are two in mounted chargers, the one forward of the other.” So, he brings the correct one. Versus. “ Down there where I have my chart out. It’s the one on your left.” The first example specifies an actual location on the boat; the other does not.

 

[Scott T-Bird]

What about fasteners installed with torx, Robertson, and other screwdrivers ?

What if you use a drill driver to install the Phillips screws, instead of using a screw driver ? Does that make the fasteners, drills instead of screws ?

Torx, and Robertson heads are screws, assuming they are smaller than say 3/8" dia. I just didn't want to list all the variations because I know I'll miss something. To me, it all depends on the head. If you insert a tool into a receptacle within the head, it's a screw. So a drill driver with a phillips bit is screwing a screw (it's not drilling). If the tool or bit surrounds the head of the fastener, the fastener is a bolt. I know, I called the Allen head a bolt .... I won't quarrel if you call it a screw, but I think exceptions can be allowed! The allen key really can be sort of a unique wrench and I call any fastener that is secured with a wench, er wrench, a bolt.

 

[FastOlson]

If sailors are hung up on using correct terms, it’s so we can talk to each other when working a boat or ship. To a crew, “please fetch my hand-held VHF radio.” “Where is it?” “Below at the nav station, outboard side; there are two in mounted chargers, the one forward of the other.” So, he brings the correct one. Versus. “ Down there where I have my chart out. It’s the one on your left.” The first example specifies an actual location on the boat; the other does not.

Bingo! Worse yet, here you are communicating with a gaggle of total strangers across the internet. The only thing they will have in common to assist you or each other is accurate terminology. Words really do "have meaning" in this situation.

And be careful of reviving the "self tailing Wench" thread... again....

 

[Dalliance]

I Googled this and… oh boy…it’s not a new question. The short answer is that a bolt requires a nut to secure it and a screw does not.

 

[Leeward Rail]

If you insert a tool into a receptacle within the head, it's a screw.

If the tool or bit surrounds the head of the fastener, the fastener is a bolt.

That makes sense. And I wouldnt qualify it via size.

a cap screw has a hex head receptical...it's a screw no matter it's size.

Doesnt matter if you use a L shaped Allen key or a straight hex bit on the end of a ratchet or a hex driver bit attached to a drill or a handle or whatever.
Lots of different fasteners with recepticles are installed with ratchet wrenches and impact guns. Small and well over 3/8.

So basically.. Innie Vs outie

But the question is.. is your easy categorization..just your opinion, or....

Where are the SAE nerds ?

 

[Leeward Rail]

And be careful of reviving the "self tailing Wench" thread... again....

Why can't we ? . I missed it the first time.