4 x 40 5/16" bolts, small quantities

[servodude]

Bolted and screwed mean very different things

That's up there with "the panda eats shoots and leaves"
I applaud your efforts

-sd

[BullDog]

To me , they're bolts...

An age ago, at the Marconi Apprentices Training Centre some mechanical type took great delight in pointing out that a bolt has a length of blank shaft between the head and the thread, whereas the thread of a screw goes right up to the head.

As is so often the case when taught something in such a setting I have adopted it wholeheartedly and will take it with me to the grave.

Chris

the screw vs bolt question is tricky

There's certainly self tapping wood screws that are partially threaded - so it's not that bare bit per se!

And if a machine screw is threaded up to the head and that head can't be turned with a screwdriver (be it slot, posi, Phillips, torx, Robertson, hex, whatever) it really must be a bolt?

But otherwise - yes
- machine screws with a bare bit would be bolts in my book

-sd

Screw v bolt - Basically, a screw is threaded it's entire length from tip to under the head. A bolt isn't, it always has an unthreaded length under it's head. So, you can have a hexagon head screw and a hexagon head bolt of the same thread and length. The screw will be fully threaded and the bolt won't be. I know we can all think of exceptions, but that's basically the difference in engineering terms between a bolt and a screw.

[jfgw]

An age ago, at the Marconi Apprentices Training Centre some mechanical type took great delight in pointing out that a bolt has a length of blank shaft between the head and the thread, whereas the thread of a screw goes right up to the head.

I would apply that to a hexagon headed bolt or set screw.

I would call this a screw,

https://www.cromwell.co.uk/shop/fasteners/shoulder-screws/m10-x-12-x-12-a2-st-steel-socket-shoulder-screw/p/QFT6068595K

I would call this a bolt,

https://www.toolstation.com/coach-bolt-nut/p60286

My understanding:
Screws are screwed into something, whereas bolts are used with nuts. The problem with this distinction, however, is that machine screws can be used with nuts.

I have heard it argued that, if it has a screw head, it is a screw.


Julian F. G. W.