Alternate to Stainless Steel Bolts

I think your chances of finding a chart like that are really slim.

Do they have to be screws? Could it be riveted, welded, or glued?

I'd discourage the use of plastic as it tends to be very susceptable to deterioration from UV. Aluminum alloy bolts would work, but are likely more expensive than stainless and aluminum has a tendancy to gall and is easy to cross-thread.

Stainless steel is old-tech and boring, but it works.

Plastic fasteners will deteriorate mainly due to UV. Its strength is very less compared to stainless steel. I do not think, strength has any criteria in these panels. To reduce the cost, you can galvanize or nickel-chrome plate mild steel bolts. But before all these, why do you have to replace SS bolts? Also, is it worth trying other bolts considering that SS bolts may cost just a fraction of entire panel.

Aircraft quality bolts may be a useful alternative option. They are certainly resistant to carroding and are quite strong. They are manufactured in great quantities, thus maybe cost effective.

Take a look!

Toomuchfun

This itself is interesting, Just not too sure as to what exactly to look for, when searching out a supplier of these/

help?

Joe

Hello Guest,

you already have the answer but, just in case I searched for the bolt size mentioned in the original post + aircraft grade. Got a whole lot of stuff up.

Take care

Hello NSS,

are you able to tell me what size bolts you want? Are they self screw or nut and bolt? And are they the bolts that hold the glass etc together on the actual solar cell, or, are the bolts which you use to fit the frame together the solar cells are on?

Is this for manufacture or just for a couple of solar cells you have.

I know I am nosey, but forgive me. Just trying to help...........

Hello NSS,

are you able to tell me what size bolts you want?

Mainly 1/4-20 and 5/16" sizes. some HEX head,, some flathead ( countersunk )

All with nuts. no aluminmum threads here, that's just asking for problems.

And are they the bolts that hold the glass etc together on the actual solar cell, or, are the bolts which you use to fit the frame together the solar cells are on?

Strictly framework. flat structural aluminmum shapes, channels,, angles, flat pieces, etc. All flat surfaces joining to other flat surfaces.

Is this for manufacture or just for a couple of solar cells you have.

manufacture

I know I am nosey, but forgive me. Just trying to help...........

I have no problem with that!

Joe

Hello Guest,

still not joined or signed it?

I thank you for the info on the size and use of the bolts.

Nit-picking here........but, it would be easier to read your post when you are printing part of another post and then answering it, if you typed the question you are replying to in Italics?

Have you any idea how many bolts you use per week or month?

And have you found a supplier yet?

Are you able to tell me roughly where you live, the State?

Do you want to collect or will you pay for delivery? It is just that these items are heavy and you could end up paying almost as much for delivery as for the bolts?

I live mostly in the UK and Europe and In the UK the mention of 'AIRCRAFT GRADE' will insure you pay an extra cost! Even though the bolts may not be a suitable size and completely out of date for any actual aircraft use, on modern aircraft I mean. This applies only if 'aircraft bolts are on your menu of course!

Take care..................

when you use plastic plastic plastic becomes brittle no Stainless is the best choice or bronze

teflon coated cs bolts and nuts best suit for this application. As we are using in sea water system of our plant.

then naval bronze is your only choice or would be or me

The aluminum is handling the corrosive sea water environment?

Hello NSS, I have done a search on google for the bolt size you mention (which I did not notice before my first reply, sorry), and I searched for: "1/4 x 20 bolts aircraft grade" This is the search page: http://www.google.co.uk/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGLJ_enGB294GB294&q=1%2f4+x+20+bolts+aircraft+grade This is one company from that page, which gives sizes and prices as well. http://www.lambcomponents.com/search/index.htm Hope this helps. I will now do a search for stainless bolts to compare the costs.

How about those sleeve type bolt and nut sets they sent you to put childrens swing sets togeather.

Those things last for ever because the nut is actually a long threaded sleeve that covers nearly the whole bolt.

What about aluminum fastener?

No creep, anodized with different colors

In reply to your question I can only say that I don't consider plastics as an alternative to serious bolting. I don't know what grade bolts you are using, but as a first step you have to make sure that you are using the cheapest SS. This means not an austenitic grade like 304, even thou the ferritic grades are also not cheap. Another possible option would be to use galvanize simple, galvanized steel bolts.

Sensei

It must be remembered that plastic bolts and nuts also soften,weaken and stretch with heat.Some solar panels are made to use on boats or desert areas with corrosive deposits.These require a higher and more expensive grade of stainless.What grade do you require?

Will galvanized do?

There are too many missing pieces of your requirements to do anything but guess at a answer in my belief.How strong does your fastener need to be?How strong is the material that it is holding?I have seen many outside structures wind damaged in my 63 years.Most were material failure.Few were fastener failure.

A cheap simple aluminum or SS pop rivet may well work in your area and are simple to remove.

I regularly used bolts ranging from nylon to 317 SS in chemical plants.Many can be and are custom made in a machine shop.We must remember that agricultural manure,urine,pesticides,chemicals,fertilizers,Bird droppings and industrial chemicals in the air can all be very corrosive.Alfred

Hello Guest,

I think you are right and, more info' would be helpful.

I have asked whether the bolts are for the supporting structure or to be used on the solar cells themselves. But no reply yet.

I have mislaid my 'crystal ball' so will have to wait on a reply........

I read a few answers here and I think he wants to be able to assemble and disassemble the panel, that's why he has to use bolts and not rivets, welding or glue. (Otherwise Al rivets would do the job, and the hole would have to be a smaller diameter than 1/4").

sensei

If the prize is the most important factor, I suggest to use just standard iron bolds and change 'em before they rust. In the long run, it'sgoing to be more expensive, but momentarily it is the cheapest.

If you care more for "quality", then go for titanium bolts. They are stronger than SS, the weigh less than Aluminum, but they cost a lot.

For you to decide.

Hello,

Hello Mr original poster? Can we have some response to some useful help and advice please? No offence..............

Back to Basics!

Steel with Cad-Pass

Steel with Electro Galvanized finish.

MAY NEED REPLACING EVERY 10 YEARS -OR coat with grease once a year.

mm

Globalspec has suppliers of plastic fasteners, their fastener e-newsletter just featured one last week. Just make sure that the fastener has a high UV factor. Because of that, it may turn out that the SS may be the way to go.

Insufficient information, and as posted it makes no sense--you have it assembled with SS, then why even think about replacing it? Unless, as suggested above you are manufacturing panels.

The answer will depend upon all of the questions asked above:

What strength is required?

How is the loading applied?

If they're holding the panel sandwich together, then the load will be axial, but othere structural bolts will receive side-loading.

What other materials will it contact?

Standard galvanized steel could be used with teflon or HDPE sleeves and washers to eliminate contact with dissimilar metals. Both materials stand up well to harsh conditions.

Titanium nitride coated bolts would probably work too.

As stated above, Aluminium would work--but it is not a great choice if the panels need to be disassembled frequently as the galling and deformation of threads is bound to occur with repeated disassembly-assembly.

have you considered zinc plated or copper plated steel

Chris

Why not simply Galvanized hardware with a thorough final assembly cleaning and then a good protective coating.

A good alternate in offshore production facilities, the type of structures which remain in place for the life of the field is to use Carbon Steel Teflon Coated fasteners.

A quick search on Google finds quite a few vendors.

As an aside, most derricks on offshore drilling platforms are totally galvanized with the entire structure bolted together. So, I would think standard galvanized bolting should last quite a long time.

Mike Martin

Houston, Texas

I see two alternatives; either would probably work well.

1. Alloy steel fasteners, zinc plated and chromated with a plastic sleeve surrounding the bolt and plastic washers to prevent galvanic corrosion.

2. Stainless steel.

A man who builds racing cars told me that he uses MIL spec fasteners which he buys from a surplus house. Unfortunately, I don't know the name of the surplus house and I've lost touch with the man. This would probably be a good solution if you're not in large-quantity production.

Plastic would not be likely to hold up over a long time, especially if exposed to sunlight. Depending on the meterial, it might creep or become brittle.

If you are worried about the cost of the SS bolt, how the !@#$ are you affording solar cells? They are not that much more costly than grade 8 bolts. I get mine at ACE Hardeware. SS bolts are much much stronger than plastic bolts. They are stronger than even grade 8 bolts. Also plastic will degrades with uv (sunlight). Stick with the SS bolts don't buy themone at a time. Buy a box. Once you buy 10 you've paid for the whole box.

I suggest standard bolts and a can of Krylon. If John Madden uses it how could you go wrong? You could use a polypropylene bolt which has a better UV resistance than just regular plastics and a much higher tolerance for heat. What is wrong with the stainless steel bolts that are in it currently? I cannot imagine they are bad unless this thing is sitting in sea water and acid. How many bolts do you need and what size?

Hey guys,

For those of you requesting additional info from NSS, the original poster:

He replied again with more specifics in Post 29, but was not logged in, just as a Guest. Same name "Joe" in the salutation.

Mike

It has been my experience from many years of sailing that SS used in direct contact with Aluminum freezes and usually results in sheering off the bolt when trying to remove after 5 or so years of exposure. This may influence your choice of fastener material. The suggestion of using plastic washers (+ plastic bushings to isolate any dissimilar metals) would be advisable if easy disassembly is a requirement.

Komplex KT

This opens up a whole new can-O-worms.

I always thought SS was a somewhat "Neutral" material, like it gets along with most anything.

This is the first i have heard of this.

Joe

Dear Komplex KT, the marine environment is much more aggressive than normal atmospheric conditions. The example is not really relevant here. Under normal conditions a solar panel is not exposed to sea-water and water droplets being blown by the wind.

Unless the solar panel is on a ship, and he should have told us.

sensei

1. Use nylon bolts

or

2. Use cheap GI bolts with a coat of paint! if you don't need to disassemble more freqently (you may required to apply paint remover otherwise)

3. remember, quality never be so cheap!!!

njoy

peetees

Plated bolts work well for corrosion protection and don't gall like stainlless. Typically nickel plated.

Galvanized works, but can bind when threading. The galvanizing goes away after a while.

You may want to consider cadmium plated fasteners.

While cad-plated fasteners would work nicely, they are restricted in many uses today because of their cadmium content. Cadmium is restricted by the RoHS (Regulation of Hazardous Substances) rules enacted by the EU nations. Any non-Aerospace or Defense products are prohibited from using cadmium, lead, beryllium and a host of other substances.

Hello osborne83,

You are quite right. The use of cadmium plated fasteners is not environmentally friendly and is therefor not a good idea.

Hello NSS,

Have you thought that plastic of any kind holding your panels together, could end up as very bad PR? And you may well be shooting yourself in the foot here.

What percentage of a cell's cost is the SS bolts? See what I am getting at here? No offence, OK?

How many bolts are in a panel? And how large are these panels? Can you direct me to your site?

Selling them with SS or 'aircraft quality' (and that secret word QUALITY drills into the brain, sounds good right?) bolts could be seen as going for the 'Premium' end of the market.

Plastic, sounds cheap by comparison. And you may loose more potential customers if you go that route. Just a thought thats all.

On the other hand four fingers and a thumb, nooooo...........On the other hand, if the bolts are not used to hold the glass and aluminium panels themselves together, but, are used in any supports there may be, then any silver coloured bolt would look and work alright.

How long do you think your panels may last? Does the actual solar cell have a life, after which it either starts to fail by not making power, or just stops working.

If you are worried the cells may break, or the glass may break because of corrosion then that is a sensible reason to look for a non corrosive bolt material. If the bolts are not even seen as for instance when used on a sub-structure, and, cannot damage the cells at all then, 'gold instead of silver' seems a bit excessive.