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Wanted: a couple of UNF bolts

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kavermei

kavermei

Member
Joined 2005
Hi,

would any of you guys from the US or Canada be willing to mail me (4) UNF (not UNC) 5/16" bolts, length 1-1/2"?

I need those to mount an old American plate transformer. I can get them locally but only by the box, which seems a little silly.

In return I could send some terminal strips (brown resin, ex-USSR stuff).

Anyone closer by who has a box of those is welcome to respond too, of course.

TIA
Kenneth
 
kavermei

kavermei

Member
Joined 2005
Yes, that's right, it has to be 5/16"-24. These are for mounting a sealed transformer which has internally threaded holes, so I don't need any nuts.

The bolts will not be visible so the style and material are not very important, but I most prefer stainless hex socket caps. Partial thread is okay too, full-length thread is not necessary.

Thanks for looking!
Kenneth
 
boywonder

boywonder

Member
Joined 2008
AndrewT said:
Hi,
bolts have a shank between the head and the thread.
A set screw has no shank. The thread extends to within 1.5 pitches of the underside of the head.

Generally, bolts are used when the joint requires resistance to shear loading.
Click to expand...


I'm assuming that you are comparing bolts to screws, not set screws.....as set screws are headless :eek:

Some bolts do not have a shank between the head and the thread, i.e. short full-thread bolts.

Machine screws come in pan, socket, button, truss, etc head styles and generally do not mate with a nut, although you are certainly free to use one on a machine screw. Some screw head styles are typically not available in very long lengths (ie button head). Machine screws are also commonly used in joints subjected to shear loading.


Bolts generally mate with a nut and are typically hex head, although you are certainly free to use them without a mating nut. Bolts are also commonly available in much larger sizes than machine screws.
 
A

AndrewT

R.I.P.
Joined 2004
boywonder said:
Some bolts do not have a shank between the head and the thread, i.e. short full-thread bolts.
Click to expand...
if the bolt has no shank, then it is a set screw.
A bolt always has a shank and that shank takes the shear load, if any. There is an exception I am aware of: Friction grip bolts (FGB)

I don't believe the US association of Structural Engineers have changed these definitions.
 
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A

AndrewT

R.I.P.
Joined 2004
not quite exactly.
Screws are headed fasteners that do not meet specification.

I think the headless threaded fastener is what we call a grub screw, often socket headed although cheap ones can be slotted.

I do not agree with 3a.
Structural engineers and automotive engineers will disagree that a bolt can have thread all the way to the head.
Similarly engineers will contest the idea of an all threaded fastener taking shear load. Except for those HSFGB
 
boywonder

boywonder

Member
Joined 2008
AndrewT said:
not quite exactly.
Screws are headed fasteners that do not meet specification.

I think the headless threaded fastener is what we call a grub screw, often socket headed although cheap ones can be slotted.

I do not agree with 3a.
Structural engineers and automotive engineers will disagree that a bolt can have thread all the way to the head.
Similarly engineers will contest the idea of an all threaded fastener taking shear load. Except for those HSFGB
Click to expand...


Yes, your grub screw = our set screw, usually internal hex socket or slotted.

I struggle with 3b in the reference, since I use zillions of machine screws and they never cut their own threads unless we are using thread-forming screws for screwing into plastic ("plastite").

For medical device design, we always use machine screws and very rarely specify nuts for ease of assembly, and reduced parts count. I'm struggling to remember the last time I specified a bolt in a design. If we do specify nuts, they are PEM-style nuts or riv-nuts that get swaged into the mating part.

Plenty of machine screws have shanks and are not fully threaded.
 
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