Using bronze ceramic screws

So we are planning on building another shed at the lab here, and I'd like to know if anyone can help us out with some information.

We are planning on using some bronze ceramic screws, these specifically, and I'd like to figure out if there are any health problems with using them, especially in regards to the possibility of the screws leeching toxins into the soil over time.

If we can't get any good information either way about the bronze, we'll just go with stainless steel, but seeing as the steel is more expensive, we'd prefer to use the bronze.

Thanks in advance!

Jesse Markowitz : If your local supplier does not have the MSDS sheet for these Bronze ceramic screws, the box they come in should give you enough information
to track it down! If you have any trouble reading the Sheet ask a fireman !

For the Good of the Craft ! Big AL

Hi Jesse,

There are several brands of these ceramic-coated screws on the market. Most are in the “structural category,” stainless steel screws often are not…so be careful there. As far as toxicity, I am sure that being a manufactured product, they are anything but “non-toxic,” yet when it comes to appeasing our PE on some projects we are left with no alternative in securing things like joist and purlins, thought the “wooden peg/trunnels” have held up well for hundreds of years in the buildings we restore. This coating is most likely inert once dry and I have never been able (yet) to get an MSDS on them, so let us know if they can be found.

Wooden pegs have held most of the world together very nicely for thousands of years, from ships to roof shingles and timber frames to wall planking…They aren’t as fast though always…

Regards,

j

jesse markowitz wrote:So we are planning on building another shed at the lab here, and I'd like to know if anyone can help us out with some information.

We are planning on using some bronze ceramic screws, these specifically, and I'd like to figure out if there are any health problems with using them, especially in regards to the possibility of the screws leeching toxins into the soil over time.

If we can't get any good information either way about the bronze, we'll just go with stainless steel, but seeing as the steel is more expensive, we'd prefer to use the bronze.

Thanks in advance!

Reading that page, those are hardened steel screws with a ceramic coating. The "Bronze Star" is a brand name, not a material reference.

The way I understand it these screws and those buy other manufactures, do have a " Bronze Ceramic Coating." It is more than just a trade name. Many of these fasteners like this may not be rated for "dynamic structural connections" yet most of these "Bronze Ceramic Coated" and related types are as I understand it from our PE, that is why the are specified in design drawings.

Jay, I read the description at the link. Steel screws with a bronze colored ceramic coating. "Bronze Star" is a trade name.
Nothing in the specificstions on that page says there is actually bronze in any part of these things.

Granted, it does not say what makes up the coating.

http://www.qcsupply.com/power-pro-outdoor-wood-screw-1-lb.html

Different brand name, but here it says multiple layers of coating with zinc and polymer, described as bronze ceramic coating.
If actual bronze is involved, I would think they might mention copper as well as zinc.

Hello Peter, et al,

Thank you for doing all that reading on this subject...

We have been using these varied products for about...maybe 10 years now...perhaps longer. Several different brands of them at one time when we are in a bind out west of in one of the more "out of the way spots" (thank goodness for shipping companies.) In the trade shows, they are all described as having a "bronze ceramic finish" some reps proclaim it being a bronze alloy matrix (truth...?...who knows.) I have been trying to get an MSDS for a while now on the finish....so...if anyone wants to really help...find that!

We use these, as I said, more than we would like, yet that is the nature of working with a foot in both worlds..."natural/traditional" and the "commercial" building world. I imagine we spent (probably more) $5K on these just in the last 10 months on all the different projects. I do have to admit from a "historic conservation" (not restoration) perspective, they do extend the life of many old joints and also prove to be really handy in many application where a "fast" and strong "pulling" connection is required. Generally a positive asset...if I can get a the MSDS I will feel better myself.

We tend to lean toward GRK Fasteners being the best overall though more expensive than many. I would also recommend only "star" or "spider" drive styles as they are the most enduring when driving into vintage (old and hard) or green wood. I have also, because of this post thread, reached out... AGAIN...to see if I can secure a MSDS on the coating. If anything comes of it, I will post it here, as I hope others would as well.

Regards,

j

Are you using these below grade? I don't believe they are rated for below grade use, so for the buildings I have seen you guys building, I would choose SS.
For above grade structural connections, I prefer a through bolt method. These screws are cool and I built a log cabin using them, but I prefer a real bolt with a nut on it.

That is a really good point not to brush over Bill. Thanks for emphasizing it.

No matter the fastener...they do have life spans. In timber frames, this “viable lifespan” is in a state of near homeostasis. Unfortunately, particularly in modern construction modalities, this cannot be said. All too often, the metal ties in concrete work, and lags in deck ledgers or the related are out of balance with the viable lifespan of the other assembly materials.

If SS fasteners are employed, as Bill has wisely suggested, they must be a “dynamic load bearing structural form.” If some other form is chosen, like ceramic coated fasteners, then these must either be protected well from corrosion for as long as possible; backed up with a more enduring vernacular fastener (wood peg), or have a planned method of replacement, and/or discontinuance of need.