Rated Bolts?

Status
Not open for further replies.
S

splinetto

Senior Member
Location
Missouri
Are there nuts and bolts that are UL listed? I tried to find some,at supply houses, but I couldn't. Everything else is rated why wouldn't the nuts and bolts? For ex mounting lugs in a transformer or mounting lugs to the bar of a CT.
 
Our POCO used to require al hardware. Now I just use SS.
Never heard of any requirement to use listed hardware and its just not available.
 
Thats a good question. When I have to add a lug I take the factory hardware up to the Mom and Pop hardware and match it up. But I believe this thread is going to head toward the factory tech. direction.
 
If anyone is intrested I can post the torque values & tensile strength of various grades & sizes of bolts & nuts.
 
When things are UL listed they are usually listed for a specific purpose. You will notice that motors are usually not listed as the same motor could be used in a pool pump or an A/C condensor.

Bolts of course would have the same issues. The same bolt could be used for anything from bolting a steel beam to a column to bolting your gate to a post.

Now as others said there are specs on bolts and you may be required to use a certain one for a certain application.
 
Bolts have grades and are marked on the head of the bolt and on the nut there my be lines or dimples,

(If a UL listed device is made with type of bolt and that bolt needs replacement replacing with the same type and materials would be strongly recommended and changing to a different type may render the device unsuitable for service.)

A Inch bolt with out any markings would be considered a grade 2 bolt,
with 3 markings a grade 5 and if 6 markings a grade 8 bolt, and the grade is the indicator of the tensile strength of the bolt, includes both fine threads and coarse threaded bolts, most lags are grade two but may find some in the grade 5, on occasion one may find other grades but the grade 2 5 and 8 are the most common, besides the bolt there are coatings to increase it corrosion resistance, and then there are bolts make of other materials other than carbon steel, (stainless steel, aluminum, copper and even plastics),

http://dodgeram.org/tech/specs/bolts/SAE_bolts.html
http://www.raskcycle.com/techtip/webdoc14.html

Metric bolts are marked as well, but using a different system of markings,

http://dodgeram.org/tech/specs/bolts/M_bolts.html

The grade marking I believe are for carbon steel bolts, only,

torque spec, for more common hardware found in electrical boxes.
http://www.ilsco.com/newweb/IlscoHome.nsf/Web+Pages/Torque+Information


other metals and materials for bolts, torque specs.
http://www.engineersedge.com/torque_table_sae.htm


good article on bolts, preload and torque and torque wrenches, (no not pointed to the electrical industry, but great info for bolts in general)

http://home.jtan.com/~joe/KIAT/kiat_1.htm
http://home.jtan.com/~joe/KIAT/kiat_2.htm
http://home.jtan.com/~joe/KIAT/kiat_3.htm

If torque specs, are given by a manufacture follow them rather than a generic chart.
 
Builder has provided a lot of good information.

In the past I had to learn a lot about hardware...just like anything there is a lot to it if you look into it.

That said I stay away from stainless steel fasteners for wire connections.

No need for it in most instances, the gear manufactures do not use stainless steel on bus connections.

Stainless steel nuts and bolts can fuse together long before the desired torque is reached.

More info here

Tightening and Galling

As with all fasteners the proper installation of stainless steel products is critical to its performance; this is particularly so with respect to tightening and galling.

Galling occurs when the stainless steel oxide surface film breaks down as a result of direct metal contact. Solid-phase welding can then take place (whereby material is transferred from one surface to another). The symptoms of galling include surface damage and seizing and freezing up of equipment. Galling commonly occurs when using stainless steel nuts and bolts together, where the contact points are subjected to high tightening torques.

Fasteners made in accordance with internationally recognized standards should ensure the uniformity of threaded products. Reasonable care should be taken when handling stainless steel fasteners to avoid any thread damage and keep the threads clean and free from dirt, coarse grime or sand. If the threads are tightened on sand or dirt the possibility of galling or seizing is increased.
Click to expand...

Unless there is a spec I usually use grade 5 (3 marks) coarse thread.

The reason I chose grade 5 is that is some guaranty of quality. A 'no grade' cheap hardware bolt could be made of anything. I find that grade 5 has more consistent quality and it happens it is what you find in a lot of switch boards.

Grade 8 is good stuff but overkill for our purposes.
 
Tony Ottenlips said:
Are there nuts and bolts that are UL listed? I tried to find some,at supply houses, but I couldn't. Everything else is rated why wouldn't the nuts and bolts? For ex mounting lugs in a transformer or mounting lugs to the bar of a CT.
Click to expand...

There are washers called "Beleville washers" that keep pressure on the buss or lug and you see them in most factory installs. Bolts and washers are just that "bolts and washers" the buss bars and lugs are the conductors. As long as you use correct torque specs ''that you can get from the manufactuer of the transformer or panel '' your good to go.
 
Around here we have a POCO that requires "nonmagnetic stainless steel bolts, nuts and Belleville washers" on all of their CT connections.
 
infinity said:
Around here we have a POCO that requires "nonmagnetic stainless steel bolts, nuts and Belleville washers" on all of their CT connections.
Click to expand...


Yes some POCOs have those requirements.

That does not mean it is the best idea, keep in mind it is also the POCO that has great ideas like requiring ground rods even if you have ufers.:D
 
Status
Not open for further replies.
Top