Brass Nuts & Bolts - Where to Get Them?

[Supervstech]

What about the resistance of the stainless steel?

This is why The lugs ABSOLUTELY POSITIVELY must be in direct contact to the wire terminals. No washers under them.

 

[Santa]

Best conductor is silver. Copper seconds, followed by aluminium.

Your lugs are also plated, usually with tin. If you are worried about galvanic corrosion, use an antioxidant compound.

The correct solution to not stripping the threads is not overtighten the screws.

As said earlier, all professionals, all manufacturers and all hobbyists use stainless fasteners. They are the best tool for the job.

FYI -The Battleborn batteries "come standard with a flag style terminal post with a 3/8” hole to accommodate a 5/16” bolt and lug sizes up to 2 AWT. Larger lugs may require a 1/4" bolt. All batteries ship with 18-8 stainless steel 5/16 – 18 bolts, BRASS washers, and 18-8 stainless steel nuts with nylon inserts. If multiple lugs are used, the washers may be removed, or longer bolts may be required in order for the bolt to fully seat into the nylon insert of the nut". I think the terminals are solid brass. Am I wrong?

 

[sajjen]

FYI -The Battleborn batteries "come standard with a flag style terminal post with a 3/8” hole to accommodate a 5/16” bolt and lug sizes up to 2 AWT. Larger lugs may require a 1/4" bolt. All batteries ship with 18-8 stainless steel 5/16 – 18 bolts, BRASS washers, and 18-8 stainless steel nuts with nylon inserts. If multiple lugs are used, the washers may be removed, or longer bolts may be required in order for the bolt to fully seat into the nylon insert of the nut". I think the terminals are solid brass. Am I wrong?

They send stainless hardware. What is your point?

 

[Supervstech]

FYI -The Battleborn batteries "come standard with a flag style terminal post with a 3/8” hole to accommodate a 5/16” bolt and lug sizes up to 2 AWT. Larger lugs may require a 1/4" bolt. All batteries ship with 18-8 stainless steel 5/16 – 18 bolts, BRASS washers, and 18-8 stainless steel nuts with nylon inserts. If multiple lugs are used, the washers may be removed, or longer bolts may be required in order for the bolt to fully seat into the nylon insert of the nut". I think the terminals are solid brass. Am I wrong?

battleborn Terminals are solid brass.

I don’t know why “larger lugs may require 1/4” bolt” some lugs might only have a 1/4” hole in them... don’t use those lugs.

I would use the bolt that fits the battery terminal hole, and get lugs with that size hole as well. If stacking lugs, longer bolts will be needed.

 

[Supervstech]

The resistance of the bolt material only comes into play if current is forced to flow through it.
As long as a direct path is made with the low resistance material of the lugs and terminals, the bolt resistance will not come into play.

 

[Santa]

They send stainless hardware. What is your point?

the terminals are brass (you said the terminals are usually tin coated)EDITED

battleborn Terminals are solid brass.

I don’t know why “larger lugs may require 1/4” bolt” some lugs might only have a 1/4” hole in them... don’t use those lugs.

I would use the bolt that fits the battery terminal hole, and get lugs with that size hole as well. If stacking lugs, longer bolts will be needed.

Yeah, I saw that too and asked about it. Was told by JH to use the same size bolt as the hole. I'm all good now. Thanks.

 

[Supervstech]

the terminals are brass (you said the terminals are tin coated)

Yeah, I saw that too and asked about it. Was told by JH to use the same size bolt as the hole. I'm all good now. Thanks.

He was swapping terms. He meant many wire lead terminals are tin plated.

 

[JeepHammer]

I spoke with Battle Born about threading the terminals for extensions to get the terminal out to the sides of the batteries, and they use a version of low Electrical Resistance brass (opposed to structural/tool brass).

For those that don't believe the bolt can or would conduct electrical current, I would point to the heavy duty breakers, switches, lugs on high amp contactors, etc.
The bolt can very well pick up amperage on the 'Off' side of the BB terminal, and conduct it directly to the 'Off'' side of your cable terminal, adding to the total amperage load being moved.

Electrical current doesn't 'Magically' stop at the terminal to terminal interface...
For the same reason you use heavy lugs and over gauge wire, you *CAN* use a brass, or even copper bolt it DECREASE Resistance & INCREASE Conduction at the connection joint.

Air gap, tapers, radius edges, small bolts in big holes are ALL missed opportunity to increase Conduction.
Since most ELECTRICAL conductors tighten to INCH POUND specifications, a heavy duty structural fastener isn't necessary, you simply don't need a Grade 8 bolt for an electrical connection,
Which by the way when overly tightened against brass/copper will deform the brass/copper, denting it, and you LOOSE conduction surface you can make contact with...

As for dissimilar metals...
Copper is copper, electrical brass is about 75-80% copper, bronze is 90% copper.
Even cartridge brass (most common) is 70% copper.
*IF* YOU (personally) want to stick a steel bolt/nut/washer in there, it's your system, do what you want.
Just don't try to sell carbon steel or nickel steel ('Stainless') as as a proper electrical conductor to anyone else...

Silver is the best (common) conductor of electrical current.
Copper is the second best (common) conductor of electrical current.
Brass or bronze beat aluminum with high amp DC.

With copper, bronze & brass bolts/nuts/lock nuts available, and only using two per battery,
I don't see the reason for a flame war if someone wants to use them like high amp industrial applications REQUIRE.

The more you spread the ELECTRICAL CURRENT out over HIGHLY CONDUCTIVE MATERIAL the less any one part of the joint has to deal with.
You use big cables, and if you are smart, big terminals with lots of contact surface area, but using the bolt to conduct even more and spread that current out even further is INSURANCE when age, tarnish/corrosion, etc set in, and they WILL set in, it's just a matter of time & environmental conditions...
What is 'Easy' is rarely 'Correct', Like Crimping (mechanical connection) and not using a proper silver bearing electrical solder (100% electrical connection)...

We are talking in excess of 100 Amps here, all that YOU paid top dollar for the panels to produce, the batteries to store, and the copper to move around.

And then cheap out on 5 cents worth of solder and $2 worth of brass or copper bolts...

All that expensive copper, panels, batteries, EVERY WATT COUNTS, and electrical resistance burns watts, restricts amperage movement, ect.
Considering the proper solder seals the copper against moisture while maintaining a solid electrical connection, and brass bolts keep electrical resistance out of 100 or 200 Amp circuit, what do you think that $2.05 worth of solder/bolt is worth when your harness doesn't have to be taken down for 10 YEARS (warranty life of Battle Born batteries) of constant use without fails?

 

[Supervstech]

I spoke with Battle Born about threading the terminals for extensions to get the terminal out to the sides of the batteries, and they use a version of low Electrical Resistance brass (opposed to structural/tool brass).

For those that don't believe the bolt can or would conduct electrical current, I would point to the heavy duty breakers, switches, lugs on high amp contactors, etc.
The bolt can very well pick up amperage on the 'Off' side of the BB terminal, and conduct it directly to the 'Off'' side of your cable terminal, adding to the total amperage load being moved.

Electrical current doesn't 'Magically' stop at the terminal to terminal interface...
For the same reason you use heavy lugs and over gauge wire, you *CAN* use a brass, or even copper bolt it DECREASE Resistance & INCREASE Conduction at the connection joint.

Air gap, tapers, radius edges, small bolts in big holes are ALL missed opportunity to increase Conduction.
Since most ELECTRICAL conductors tighten to INCH POUND specifications, a heavy duty structural fastener isn't necessary, you simply don't need a Grade 8 bolt for an electrical connection,
Which by the way when overly tightened against brass/copper will deform the brass/copper, denting it, and you LOOSE conduction surface you can make contact with...

As for dissimilar metals...
Copper is copper, electrical brass is about 75-80% copper, bronze is 90% copper.
Even cartridge brass (most common) is 70% copper.
*IF* YOU (personally) want to stick a steel bolt/nut/washer in there, it's your system, do what you want.
Just don't try to sell carbon steel or nickel steel ('Stainless') as as a proper electrical conductor to anyone else...

Silver is the best (common) conductor of electrical current.
Copper is the second best (common) conductor of electrical current.
Brass or bronze beat aluminum with high amp DC.

With copper, bronze & brass bolts/nuts/lock nuts available, and only using two per battery,
I don't see the reason for a flame war if someone wants to use them like high amp industrial applications REQUIRE.

The more you spread the ELECTRICAL CURRENT out over HIGHLY CONDUCTIVE MATERIAL the less any one part of the joint has to deal with.
You use big cables, and if you are smart, big terminals with lots of contact surface area, but using the bolt to conduct even more and spread that current out even further is INSURANCE when age, tarnish/corrosion, etc set in, and they WILL set in, it's just a matter of time & environmental conditions...
What is 'Easy' is rarely 'Correct', Like Crimping (mechanical connection) and not using a proper silver bearing electrical solder (100% electrical connection)...

We are talking in excess of 100 Amps here, all that YOU paid top dollar for the panels to produce, the batteries to store, and the copper to move around.

And then cheap out on 5 cents worth of solder and $2 worth of brass or copper bolts...

All that expensive copper, panels, batteries, EVERY WATT COUNTS, and electrical resistance burns watts, restricts amperage movement, ect.
Considering the proper solder seals the copper against moisture while maintaining a solid electrical connection, and brass bolts keep electrical resistance out of 100 or 200 Amp circuit, what do you think that $2.05 worth of solder/bolt is worth when your harness doesn't have to be taken down for 10 YEARS (warranty life of Battle Born batteries) of constant use without fails?

I wouldn't call this a flame war, and I hope it doesnt become one.

The only point in your post I disagree with is the "over 100 amps" part.

Battleborn limits their max output to 100 amps.

I am a simple electrician. I am wrong all the time.
Please dont think my opinion is better than anybody else's.

But on a battleborn battery, limited to 100 amps, is the fastener going to be part of the circuit?

I am ABSOLUTELY CERTAIN the resistance of the steel has a millivolt inductive affect. I just wouldn't choose a fastener material that would be susceptible to vibration issues like copper or brass in a mobile situation.

 

[Deleted member 4428]

All of the telecom batteries I removed from service had brass fasteners.

 

[JeepHammer]

I wouldn't call this a flame war, and I hope it doesnt become one.

The only point in your post I disagree with is the "over 100 amps" part.

Battleborn limits their max output to 100 amps.

So, you haven't seen Battle Born batteries in parallel?
Did you read Battle Born Specs, they can throw 200 Amps for 30 seconds, double your 'Worst Case', what about that?

That would be 100A EACH, Up to 4 with no issues according to Battle Born,
That sounds a LOT like 400 Amp POTENTIAL to me...
(and why you should FUSE the battery along with a circuit breaker protecting the cables to inverter, in the event the worst happens, like a battery melts internally and the others in Parallel feed it)
I am a simple electrician. I am wrong all the time.
Please dont think my opinion is better than anybody else's.

But on a battleborn battery, limited to 100 amps, is the fastener going to be part of the circuit?

Absolutely part of the circuit.

Maybe you can post an example of how you keep the fastener OUT of the circuit when connecting to Battle Born batteries, or any other lug terminal application...?
I would be interested in seeing the electrical insulating sleeve you use to keep the fastener out of the circuit.

I am ABSOLUTELY CERTAIN the resistance of the steel has a millivolt inductive affect. I just wouldn't choose a fastener material that would be susceptible to vibration issues like copper or brass in a mobile situation.

And I'm absolutely certain I've seen steel bolts glow red and orange hot in welder connections at UNDER 100A, Same with steel terminals on 200-400A fork truck, industrial heated dies, applications that draw 100A and up.

If someone doesn't understand how resistance increases with HEAT in different conductive materials, I can't really help them.
What I can do is burn a thick handle wrench in two, thicker than the copper conductors going to that wrench.
Now, I don't recommend you reuse the copper after doing something like that, but the conductors survive, the wrench doesn't.
Same with steel bolts.

That *Should* make the point when things go wrong that copper, brass, bronze doesn't super heat nearly as fast as steel, but you do what you want to... Like I said, it's what *I* do, you so what you want to.
I'll stick with common sense, spend the extra $2.05 or so, and double down on my connections.

 

[SolarRat]

The only problem I have with using brass bolts for a battery is that it seems to me they are too ductile for occasional tightening/removing, and seem to "stretch" a tiny bit when tightening them down. I'm sure they have enough clamping force when torqued the first couple times you do it, but by the 4th or fifth time you tighten it it feels like it will, or it does, snap. A battery probably gets disconnected for some reason or another from time to time, so keep a spare bolt or two on hand.

For a 100 amp connection I don't think it matters one bit. Use'm, don't use'm, whatever. You won't notice the difference in conductivity. I personally don't trust them beyond the first initial torquing to not stretch/loosen with high stress or heat...but do it once and leave it and it'll be fine. Just my experience from snapping them. Half the time they will snap on removal if any corrosion is present. Have spares!

 

[SolarRat]

And just to fan the flames a bit , brass might be 70%+ copper, but it has nowhere near 70%+ of copper's conductivity. More like 25%...so it ain't the same thing. Its main benefit is corrosion resistance when connecting to similar metals...Brass and copper work well together. Brass fasteners DON'T work well with non SS steel, lead, or aluminum, some very common terminal materials (confusing because brass fasteners shouldn't be used on those base metals, but those metals as fasteners in a brass base metal is OK). Brass bolts on brass BB's terminals? Sure, go ahead.

 

[JeepHammer]

A REMARKABLE amount of 'Professionals' don't have any idea how a bolt/nut works, so they screw things up regularly.
Since I own a machine shop, I'm the lucky guy that got to get the broken carnage out when they twist things off, then break a hardened 'EZ Out' off in the fastener.
They can't tighten a bolt, but I'm expected to perform miracles, and when I try and explain how a bolt works, and how to do it correctly, I get told they know what they are doing and to "(censored) OFF"
Since they were standing in front of me, they OBVIOUSLY didn't know what they were doing...

Recommended torque spec on grade 8 bolt, 5/16 from battle born is 18 ft.lb.
Recommended torque spec on brass bolt, 3/8" is 16 ft.lb.
Short handle wrench and short two finger pull is all you EVER want to put on either bolt.

*IF* you twist off brass, buy a torque wrench, or 'Borrow' one from the local parts store and practice with it.

Neither Nylon or Prevailing Torque nuts of any kind are supposed to be reused, but often are.
If you insist on taking it apart over and over again, I suggest jam nuts instead of over torquing the crap out of the bolts/nuts.

AND, I'll say it again, this is how *I* (personally) do it, it's how the DC industrial equipment does it,
If you don't want to do it this way, then DON'T DO IT.

And, a little less polite, but more to the point, and there was just several threads about people being POLITE and not forcing *Their* opinions down anyone else's throats or continuing to argue about something someone does that *YOU* don't agree with.
... YOU don't get to argue against what *I* do...

So, before this turns into a crap fight about what *I* "MUST DO" with my own hardware, according to someone else's opinion, I'm done with the subject.

Since I did this stuff professionally for about 20 years, this would be the torque wrench I use most, preset at 16 Ft.Lb, and being common 1/4" drive, I don't make the stupid mistakes a lot of people do.
Notice the Red band that differentiates it from the other preset torque wrenches in the shop (about $75 the last time I bought one), but these stay in calibration MUCH longer than the beam type or average adjustable 'Clicker' type, so for actual professionals, it's well worth the money NOT to do things 3 or 4 times, twist off bolts in expensive threaded contactors, or the worst, twist off a fixed stud on something like a breaker, completely ruining it.

Adjustable torque drivers are available for less than this one for the hobby bunch,
But either you have a torque limiting driver, or you stand in front of the machinist and beg forgiveness for being none too bright and twisting the fasteners off...



I like being able to spin the 'T' handle getting nuts and bolts on MUCH faster than messing with wrench.
Things like that doesn't matter to someone doing just a few terminals, but when you do a hundred a day, time is money.

 

[SolarRat]

The day I use a torque wrench on a battery bolt is the day I start using duct tape instead! if it ain't a head bolt, rod bolt or pinion gear bolt, my torque wrench stays in the box. Brass bolts normally break on removal anyway...

Most people who use torque wrenches don't even now they need to be periodically calibrated, or that they should be used with lubed up fasteners. But it makes them feel good to use them anyway, even when way off...good for them. I use the german method.

 

[Supervstech]

Breakers and terminal lugs in main panels all have torque specs, and my inspectors always check my torque wrenches for calibration stickers. I gotta respec them every year, or anytime they get dropped.
So true about many items.

 

[jasonhc73]

Go to the plumbing aisle if you don't see them in the electrical aisle.

 

[JeepHammer]

This is why The lugs ABSOLUTELY POSITIVELY must be in direct contact to the wire terminals. No washers under them.

And what happens when the copper/brass bolts are silver soldered (brazed, not low temp electrical solder) to the electrically conductive (copper/brass) fasteners?

A little electromagnetic induction silver soldering, but I could have used brass brazing just the same, silver solder is a little more electrically conductive...






How about I pure silver solder these into the cable terminals so there is no lost connection surface area at all?
100% electrical contact with nothing more than a few cents of common coin silver, which is a better conductor than the battery terminals themselves which are brass...?

The 3/8" brass bolt shown is capable of over 100A (not Amp Hours), along with 1" of surface contact with the brass terminal I'm using resistance is cut to about zero.
That's 100 EXTRA amps through the fastener alone, not to mention the high amp terminal that contacts the battery post directly...
When in doubt, oversize.

If you check out 'Battle Born' web site, you will find that EACH battery can throw 200A EACH for 30 seconds.
Nominal discharge rate can be up to 100A continuous.
I just make the battery terminal itself the least conductive part of the system since it can't be soldered directly to because the batteries will eventually need to be replaced, even if they last for 10 years...

The point is CONDUCTIVITY, that depends on MATERIAL & CONTACT SURFACE AREA.
If the 'Washer' is MORE conductive than the terminals being fastened, and it has the proper contact surface area, there isn't much of a problem.

When someone tells people that common bolts, nuts and washers can be used... There isn't much I can do about that.