I know steel has to be better. For one thing, aluminum screws can get damaged from over tightening and you want a ground screw more than just snug. Also, aluminum corrosion could be a problem unless you use dielectric grease on the threads.

CAn I do it? Always have used steel assuming aluminum would not conduct electricity well enough.

will the electrical ground accelerate corrosion on aluminum worse than steel screws?

Will an anodized finish on the screw prevent a good ground to the frame?

The ground I'm using is the rear bolt hole in the frame where the left side sub frame attaches. The subframe has been removed and I'd like to use an aluminum bolt there in place of the big steel OEM one. It's a 6mm thread diameter x 1.25 pitch bolt. Prolly about $5 for one so thought I'd ask first and maybe buy later.

* Last updated by: Rook on 12/13/2014 @ 5:45 PM *

Also, aluminum corrosion could be a problem unless you use dielectric grease on the threads.

Always have used steel assuming aluminum would not conduct electricity well enough.

will the electrical ground accelerate corrosion on aluminum worse than steel screws?

Will an anodized finish on the screw prevent a good ground to the frame?

The ground I'm using is the rear bolt hole in the frame...

Bring it!

Cool. I'll order. It's actually an M10 bolt so that aught to be able to take a little torque to keep the ground tight.

Thanks, Hub.

I'm not so sure about the conductivity of anodized aluminum, Hub. That's basically a layer of corrosion. An unfinished aluminum screw might be ok if it was clean and had dielectric grease on it but I'm not real confident of anodized aluminum...unless the anodizing was scraped off the contact areas. Scraping the paint on the frame under the eye ring or using a barbed washer should help but the screw itself might not ground well if it's anodized. What do you think?

The whole point of anodizing was to stop the corrosion from happening on the surface. Pretty cool process. And great for grounding. It's still aluminum from outside in. Color will not affect the flow.

"An anodized surface is aluminum oxide surface, aluminum oxide is non-conductive, and anodizing is often selected because it is non-conductive"

Could I test it by using an ordinary D cell battery? a wire coming from - and another wire from + with an anodized bolt in the middle, the - wire squeezed between 2 nuts at the tip and the + wire squeezed between the head of the bolt and another nut? A flashlight bulb should should light off of anywhere along the circuit....right?

* Last updated by: Rook on 6/16/2015 @ 1:42 AM *

Wrap the bare wire around the anodized bolt. With the other bare wire end, hold it to the bottom of the battery- side. Take a bulb out of a flashlight, touch the lead bottom of the bulb to the top of the battery+ nipple end. Touch the anodized bolt to the brass body of the bulb, see if it glows the filament? If it glows, lights up, then the anodized surface is conductive to pass current thru. If you unravel the wire off the bolt, touch the brass body of the bulb with the wire alone, she now lights up, the anodized bolt is non-conductive.

OK, we'll do the test when the bolts come in. It's just a 1.50 bolt so no biggy. More I think about it, it's not for sure any ground screw will make good contact with the frame hole I have in mind. There might be paint in those threads. Best to scrape away the paint around the hole no matter what screw I use. I did that with the old ground screw on the LH side subframe. It worked perfectly for years.

1. Whenever current flows thru a conductor, it produces a magnetic field.
2. Whenever a current flows yada-yada, the wire becomes heated.
3. Sometimes, current may produce a chemical effect.

Say my lightweight anodized bolt is not conductive.
Say my azbolt threads spin into the painted threads.
Say my azbolt makes sure the wire is taking the heat is a tight bond to the bare metal.
Say my only contact needed is bare metal to bare wire.
Say my trip to NAPA for a star washer is this bites thru the paint and into bare metal.
Say my heat is addressed, my current makes a magnetic field, and 'sometimes' wires to ground do not cause a chemical effect to occur [for argument sake].
Say my battery posts are a vaseline kind of wipe all threads and cables with it. That white acid is a 3-some-chemical event. That jobber wire to ground I know does not need to be greased to deter a chemical effect.
Say you look at the bike's many ground wires and not too many grounds are greased.
Say you watch; 'start that 1920's barn job' and they kick it off with fresh gas... show me the grease on the main wire harness they beep the horn uga.

Say my only contact needed is bare metal to bare wire.

Say my trip to NAPA for a star washer is this bites thru the paint and into bare metal.

The ground would be all the better if the screw was both conductive and also made contact with bare metal threads. I'd like to have both but I'll take either one.

Say you look at the bike's many ground wires and not too many grounds are greased.
Say you watch; 'start that 1920's barn job' and they kick it off with fresh gas... show me the grease on the main wire harness they beep the horn uga.

True. I have seen no corrosion on ground screws at all. Only the battery terminals have accumulated crust. I still go with the jelly because why not? Might help...it's fun stuff to shmear on. I shmear and forget about it until next time. It does seem to eliminate the crust on the battery poles.

* Last updated by: Rook on 6/16/2015 @ 9:20 PM *

For sure battery posts. My ground corroded between batt and cable, it would charge the batt, but when a lot of amps needed to crank the motor over that last run to NAPA... click-click right in their parking lot. Got it home, found that crust happened that quick on the ground post. Vaseline is the same stuff, do not let them tell you any different about needing dielectric grease in a tube.

The bolt isn't even part of the ground, unless you soldered the wire to the bolt head. I say good to go if you scrape paint.

Here's the old ground screw. It was steel but I filed the paint off of the little bump around the screw hole where the eyelet contacted. Never had a problem with it.

The bolt isn't even part of the ground, unless you soldered the wire to the bolt head. I say good to go if you scrape paint.

* Last updated by: Rook on 6/17/2015 @ 9:01 AM *

I'm amazed that some factory ground points work at all. Ohm meter will answer all.

I can pick one of those up for $15.

My ProBolts should be here today.

Looks like the anodizing does insulate the aluminum screw.

....now abou this ohmmeter, is it like a precision test light? .....It tells you not only if there is conductivity but how strong the conductivity is?

3 years later, that aluminum ground is fine. The paint is scraped off of the metal there is contact between the ring terminal and the frame...IDT the bolt has much to do with anything but holding them tight together.

So now the question of aluminum battery bolts/nuts has crossed my mind. Could save a tenth of an ounce or so...should I do it? --I mean, if steel battery bolts come loose you're just as screwed as you would be with aluminum battery bolts--NO?

Anyway, if you can get non-anodized bolts and nuts (not that I plan to) aluminum is a pretty good conductor. As Hub pointed out, what is the frame made of? as long as there's no paint or anodized surface insulating contact, ground away.

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/61000-need-new-bolt-battery-terminal-metal-best.html

* At 20º Celsius, based on copper as 100.
** Per degree C at 20º C.
Note: The conductivity of various metals is subject to variation according to processing and alloy composition.

Aluminum 59
Brass 28
Cadmium 19
Chromium 55
Cobalt 16.3
Constantin 3.24
Copper:
Hard drawn 89.5
Annealed 100
Gold 65
Iron:
Pure 17.7
Cast 2-12
Wrought 11.4
Lead 7
Manganin 3.7
Mercury 1.66
Molybdenum 33.2
Nichrome 1.45
Nickel 12-16
Nickel silver 5.3(18%)
Phosphor bronze 36
Platinum 15
Silver 106
Steel 3-15
Tin 13
Titanium 5
Tungsten 28.9
Zinc 28.2