Trying to figure out the best self-tapping screws for wood and particle board - it has to be STAINLESS dome head or hex head.Have already used sheet metal screws to install a solar panel. Will add another panel but suddenly started having some doubts.There are no stainless "deck screws" - you know, those with thread similar to drywall screws - that would have dome head or hex head. When I look at "wood screws" in places like Home Depot, the thread looks identical to sheet metal screws only partially threaded, with un-threaded section of shank.Searched McMasterCarr, they have stainless "serrated thread screws for plywood" - with size, length, and head that I want.Q: What would you use to install on the roof something that is heavy and should also resist winds, using #10 screws, sometimes in 3/8" particle board, sometimes in rafters under particle board? Sheet metal screws again, or serrated threads, or... ?(I'm not asking about the right number of anchor points VS wind force, solar panel height etc - let's not go there, the panel will be horizontal or with very little tilt).PS: RV manufacturer for all the exterior used a regular carbonized steel sheet metal screws, metric - don't ask me why metric, probably they got a box on cheap from an automotive supply place. Some heads are corroding already.

There are stainless "deck screws" They come from Screw Products Inc, made from 305 Stainless. I buy the #10 X 3" & 3 1/2" in 5# containers. I also like that they come with the T25 Star Drive so that your driver doesn't slip in the head. Have been using them for 5 - 6 years.I especially like them because they don't corrode making it easy to take them out an reuse them. The reason I reuse them is because they're not cheap.I see from their web site they come in other sizes and they do mail order. SS screws ClickyI also bought smaller sizes from my local hardware store.I first started using them because I build a lot using the green pressure treated lumber - the chemicals in it will ruin standard deck screws so they weaken and fall apart. After a standard deck screw has been in green pressure treated lumber for a year or two, you can't remove them. Either you have to use SS screws or galvanized lag bolts.Bill

I used stainless deck screws from Ace Hardware. Shape of the head is fine.Mine are Robertson drive (square)

Try to stay away from Chinese stainless, not very good. Good stainless is NOT magnetic. Test it with a magnet.

You might want to check out 316 stainless material. 316 has molybdenum and is both stronger and more corrosion resistant than cheap stainless alloys. Places like West marine and Harbor Marine in Seattle have a whole selection of fasteners.

Best stainless screws for wood? | Good Sam Community

25 Replies

Housted
Explorer III
Aug 10, 2014
Try these people, I have bought a lot of items from them. Good prices and fast shipping.

Albany County Fasteners

Housted
time2roll
Nomad
Aug 10, 2014
That thread looks like a Tapcon fastener for concrete.
Almot
Explorer III
Aug 08, 2014
Dicor - yes, of course. On the roof under the solar panel bracket, AND on the screw head, AND lubricate the screw with Dicor before driving it in.

Why flat bottom of the head: because it holds a flat aluminum racket better. Deck screws I need to countersink, and some deck screws might have too long un-threaded section of shank. Sometimes there is a rafter under 3/8" particle board, and sometimes - no rafter.

PS: to what CA Traveler said - that with a countersunk screw it is easier to distort and loosen the mounting bracket - I will also add that it's easier to damage the bracket. At least, when you don't have much skills. You drill and drill that cone with an old primitive drill, the bit size is right, and then - ops - the countersink bit has almost went through aluminum plate, making the #10 hole a #12 :)

I think I'll go for "Serrated Thread Screws". Though this thread looks like what is called "high-low thread", not "serrated". 316 steel.
SCVJeff
Explorer
Aug 08, 2014
EckE wrote:
Might look at aircraft quality screws.
I'm pretty sure i have never seen a wood screw for aircraft, and never anything SS
EckE
Explorer
Aug 08, 2014
Might look at aircraft quality screws.
CA_Traveler
Explorer III
Aug 08, 2014
smkettner wrote:
CA Traveler wrote:
It "must" also be flat on the lower head contact side.
Why? The deck head will not pull through or pop off.
It may be easier to distort and loosen the mounting hardware due to the cone shaped contact and more likely with thinner rather than thicker material. So I'll withdraw the "must" word.

I just can't think of a good reason for countersink holes vs a flat contact area for this application.
time2roll
Nomad
Aug 08, 2014
CA Traveler wrote:
It "must" also be flat on the lower head contact side.
Why? The deck head will not pull through or pop off.
CA_Traveler
Explorer III
Aug 08, 2014
MEXICOWANDERER wrote:
"UNCLE!"

OK I give...!

How far "off" is the design of the screws in the link below?

http://www.homedepot.com/p/PrimeSource-2-1-2-in-x-10-5-lb-Stainless-Steel-Star-Drive-Deck-Screw-MAXS62704/203354096
Perhaps 100% as any screw used in the typical thin RV roof must be full threaded and likely no more than 1" long. It "must" also be flat on the lower head contact side.
2oldman
Explorer II
Aug 08, 2014
Coat screw heads with Dicor.
RJsfishin
Explorer
Aug 08, 2014
In the roof, I use all 3/4 (or longer) x 10 ga pan head SS from Tru Value,....are good quality, and priced right if ya buy'm by the box of 100. $7.95