Square drive (Robertson) stainless steel wood screws

[Christopher Locke]

Does anyone know of an on-line distributor of square drive (Robertson) stainless steel wood screws? A number (e.g. Jamestown) have square drive wood screws but only in silicon-bronze, not stainless steel. Many others have stainless steel screws but not square drive. Still others have square drive stainless steel screws but not in wood screws! The big home improvement places like Home Depot and Lowes do not appear to have them either. I know from friends that some local hardware stores do carry them but I've surveyed all hardware stores near where I live and they do not stock them. Thanks for any suggestions.

Christopher Locke

[ 10-18-2005, 11:10 AM: Message edited by: Christopher Locke ]

[Hal Forsen]

http://www.mcfeelys.com
HF

[ron ll]

www.tacomascrew.com (http://www.tacomascrew.com)
www.westernfastener.com (http://www.westernfastener.com)

Both West coast, but may help if you don't find anything closer.

[Ken Hutchins]

StaFast in New Bedford, Ma 1-800-678-8811

[Paulyboy]

Chris, Mcfeeleys also carries bronze cut screws, like the old time screws, instead of the newer style. I used these on the 1st small craft I built and was very satisfied with them.

[Christopher Locke]

Hal and Paulyboy, thanks for the suggestion. Please forgive my ignorance, but I had found the McFeely's site before and rejected it b/c the McFeely's flat head screws look different than the traditional wood screws in that the shank looks to be the same diameter as the root. Is that true? If so, wouldn't it be better to use traditional wood screws so that the shank fills up that hole created by the root threads and minimizes the ability of water to seep in there? Or am I missing something? Thanks.

Ron II, thanks for your suggestions too. The two links you provided are helpful but the sites don't actually let you get to the details on screws; I might order some catalogs from them and go back to the old-fashioned way of buying things!

[ 10-18-2005, 01:28 PM: Message edited by: Christopher Locke ]

[Bruce Hooke]

Christopher,

You raise an important point, and in my opinion, the answer is, no, you should not ignore the lack of a thick shank, especially in boatbuilding where that thicker shank often provides a critical margin of additional corrosion resistance. Also, that thicker shank does a better job of sealing the hole to prevent water from getting in past the screw. McFeely's does have Silicon Bronze screws with full-size shanks, but I don't think they have Stainless screws in that style, because it seems, based on the catalog, that their full-size shank, Silicon Bronze screws are mostly aimed at (wooden?) boat builders and stainless fasteners are not real popular with wooden boat builders...

- Bruce

[Christopher Locke]

Ok, so let me ask a more basic question. Should I be using silicon-bronze? The context is that I'm using Phillips head stainless steel right now but stripping a lot of them. I received Jamestown Distributor's catalog and they recommend silicon-bronze but caution that they are weak and you need to drill two pilot holes (one for the root and one for the shank ) and then use screw lubricant, and even then be careful!! Stripping screws starts to sound pretty attactive if that is what is involved with silicon-bronze!! I'd like this boat to hold up for 5-10 years but don't plan on bequeathing it to my grandkids in 50 years.

[DavidF]

I got my square drive ss screws from Jamestown. And only one in a hundred (so far) got bunged.

[Bruce Hooke]

Stainless steel has problems when it is in damp, low-oxygen environments. Under such conditions it can exhibit something called crevise corrosion, whereby it corrodes away quite quickly. Whether stainless fasteners are right for what you are doing depends a lot on the type of boat you are building. For a traditional plank-on-frame boat I would definitely avoid stainless steel screws, because the wood in such boats is wet a lot of the time and when the fasteners are buried in the wood there is also not much oxygen around. At the other end of the scale, on a boat that is stored on land or a boat that is mostly held together and sealed with epoxy, with the screws there largely as backup and to hold things in place while the epoxy cures, stainless may make a lot more sense.

For a really "quick-and-dirty" boat hot-dipped galvanized screws are another perfectly reasonable solution, and being steel they are strong.

Silicon Bronze screws are softer than steel screws, but it does not need to be complicated to use them. In my opinion, any time a real wood screw (one with a full diameter shank), no matter what the scrwe is made of, is driven into hardwood, or even the harder softwoods, you should drill a stepped pilot hole, as recommended by Jamestown. In addition to greatly reducing the number of stripped and broken screws, it also reduces the chances of spliting the wood. However, there are some nice drill bit systems out there that will drill a stepped hole with a counterink for the head, and even space for a bung if you want one, all in one go. I have one that pops out and reverses to become a square driver, which makes things very easy.

[Christopher Locke]

Bruce, you da' man. This was a big help. BTW, it is screw and glue marine plywood on pine frames, epoxied, and we'll probably fiberglass at least the seams if not the bottom as a whole, so I plan to stay with stainless steel. I'll look for the stepped pilot hole bit.

[BRobinson]

Pine frames? Nothing should strip out going into pine, even with an undersized pilot hole. I think you are doing something else wrong. Pine is soft, what your talking about usually only happens with oak.

[Bruce Hooke]

Realistically, if glue is the primary "fastener," then I see no reason why you shouldn't go with "drywall style" screws (narrow shank), of the type that McFeelys and others carry. Then you don't need to worry about stepped drill bits (however in many cases having the countersink as part of the drill bit is still quite useful).

As far as stepped drill bits go, I happen to like the Makita "Quad-Drive" system. It includes adjustable stepped bits in the most common screw sizes, and you can flip the bit around in a holder to reveal a screw driver tip. This makes it quick to drill a hole and then drive a screw with the same drill. One downside is that if you extend the center drill bit too far (as for a longish screw) then it can't be flipped around any more because it bottoms out. Here's a picture from Amazon:

http://images.amazon.com/images/P/B0000224F5.01._SCLZZZZZZZ_.jpg

Many boatbuilders use the Fuller system, which Jamestown sells. Rather than a stepped bit it uses a tapered bit, which I think is not as good as a stepped bit, but this is getting pretty picky on my part! Your local hardware store will also likely have basic stepped drill bits that will do just fine in most situations...

[Bruce Hooke]

Originally posted by BRobinson:
Pine frames? Nothing should strip out going into pine, even with an undersized pilot hole. I think you are doing something else wrong. Pine is soft, what your talking about usually only happens with oak.This is a good point. Are the screws really stripping out, or is the wood stripping out, or is the head getting too buggered up to be usable? If it is the wood that is stripping out (i.e., the screw just starts spinning in place) then your problem may well be the lack of a countersink for the head to seat into or too small a pilot hole (and your problem is definitely not the metal used for the screw). When screwing plywood to pine the pine will often strip out before the head gets below the surface of the plywood if you don't use a countersink to make space for the head. If the head is getting buggered up then switching to square drive should solve your problem. If the threads of the screws are failing then I think you should look for some different screws. In my experience the usual way that screws fail if twisted too hard is by breaking rather than by the threads shearing off. Threads shearing off sound like bad screws to me.

[Christopher Locke]

It is the head that is getting bugged out, not the threads. We're drilling pilot holes and countersinks for the heads. Typically it is just in the last few turns - I pull too hard on the power drill trigger and spin the drive in the screwhead. I can reduce that by being more careful but sometimes in a hurry, eg. when epoxy is setting. I just want something to make the process go as quickly and efficiently as possible, as I get frustrated at the end of a long day when I start stripping screwheads and the wife is yelling for me to come in to dinner, but I really need to finish that task for the day ... I think stainless steel square screws will be fine if I get the stepped pilot hole bits. Thanks a bunch for all the advice.

[ 10-18-2005, 04:37 PM: Message edited by: Christopher Locke ]

[BRobinson]

Are you using a good adjustable clutch screw gun? Proper size Phillips screw tips?

[Christopher Locke]

I think so, but possibly not.

[Bruce Hooke]

You're going to love square drives! It is darn near impossible to strip out the heads!

[Bob Cleek]

The advantage of the Fuller style tapered bit is that the taper of the hole matches the taper of the bit, providing the same bite across the whole length of the screw. I'd be somewhat leery of Robertson square drives if you ever have any thought of removing the screws (which you may not.) That little square hole is very easy to fill with epoxy, glue or whatever holds your bung in place and is extremely difficult to clean out in order to get the driver bit in there. This is why I prefer straight slotted fasteners. These are easily cleaned out with a small dremel bit or awl point.

[Bruce Hooke]

Bob raises a good point on the downside of square drives for boatbuilding. There are good reasons to use slotted screws even though they are a pain to insert with power tools. On the other hand, if the joint is also being glued with epoxy then screw removal is sort of a moot point!

On the Fuller bits, the problem, as I see it, is that wood screws are NOT tapered except at the very tip. If you look at the root (the part inside the threads) of a wood screw you will see that it is in fact straight until you get very close to the end. So, it seems to me that tapered bits do one of two things: either they drill too small a hole for the shank or they drill too big a hole for the threads just below the shank. Neither is good. However, for screws with a thin shank (drywall style) it seems like tapered bits might work much better, but you would need to use a considerably smaller diameter bit than would be usual for the screw number.

[Christopher Locke]

Not to make too big a deal of this, but if anyone else is interested in square drive stainless steel screws (SDSSS - an acronym that I will use only b/c it makes me smile), note that no-one has yet identified an online store that actually shows them on-line, hence making the discussion a bit moot ;) . In the latest WB, I did find an advertisement for http://www.ccfasteners.com, which has SDSSS, but only for #8s in 3/4". A much wider selection for silicon-bronze. If anyone comes across some other online store that definitely sells SDSSS, I'd appreciate hearing about it. Thanks for the education provided in the responses above!!!!

[Bill Thompson]

Bruce,
Does Makita make a #14 stepped bit? I tried looking at some of the advertizing sites and looks like their kits go up to #12. I was wondering if they (or other vendors) sell a #14 bit seperately? Thanks. bill

[George Roberts]

I guess to do this stuff right one should design the screws and drill bits, the drive tpye and drive tool, and the material.

But then we could not afford to build boats.

I prefer to use screws with rolled threads and size them one size larger on the diameter than screws with cut threads. a tapered drill does a nice job for those types of screws.

[Bruce Hooke]

Originally posted by Bill Thompson:
Bruce,
Does Makita make a #14 stepped bit? I tried looking at some of the advertizing sites and looks like their kits go up to #12. I was wondering if they (or other vendors) sell a #14 bit seperately? Thanks. billI'm afraid I don't know, but I suspect not based on what I'm seeing on the Amazon site.

I'm basically a furniture and small boat guy so I have not had much need for #14 screws...

[Bruce Hooke]

Originally posted by George Roberts:
I guess to do this stuff right one should design the screws and drill bits, the drive tpye and drive tool, and the material.

But then we could not afford to build boats.

I prefer to use screws with rolled threads and size them one size larger on the diameter than screws with cut threads. a tapered drill does a nice job for those types of screws.That is certainly your choice, but what I have been recommending is by no means difficult nor, as far as I can tell, unusual in the wooden boat world. I never recommended anything close to designing your own screws or drill bits, so I'm not sure where you got that from. In fact, I even recommended something very close to what you are suggesting, with some qualifications regarding the type of boat being built.

[Nicholas Carey]

Originally posted by Christopher Locke:
It is the head that is getting bugged out, not the threads. We're drilling pilot holes and countersinks for the heads. Typically it is just in the last few turns - I pull too hard on the power drill trigger and spin the drive in the screwhead. I can reduce that by being more careful but sometimes in a hurry, eg. when epoxy is setting. I just want something to make the process go as quickly and efficiently as possible, as I get frustrated at the end of a long day when I start stripping screwheads and the wife is yelling for me to come in to dinner, but I really need to finish that task for the day ... I think stainless steel square screws will be fine if I get the stepped pilot hole bits. Thanks a bunch for all the advice.What we've done sometimes is to power-drive the screws 90-95% of the way to the point where they might break and then finish the drive with brace-and-bit.

Nothing like the big, slow, controlled torque you get from the brace. Lee Valley sells a nice French-made brace that coms with both a traditional chuck for square, taper-shank auger bits as well as a modern 3-jaw chuck, the better to hold a round shank drill bits and hex-shank driver bits.

It's Item A on this page:

http://www.leevalley.com/wood/page.aspx?c=2&p=32300&cat=1,180,42337&ap=1

[Christopher Locke]

Originally posted by DavidF:
I got my square drive ss screws from Jamestown. And only one in a hundred (so far) got bunged.David, did you really get square drive stainless steel *wood* screws from Jamestown, or did you instead get deck screws? I can't find wood screws on either their website or catalog.

[DavidF]

Maybe I'm not using wood screws but what I got can be found on page 130 of the 2005 master catalogue in the lower-right corner, self-tapping square drive 18-8 stainless in flathead or panhead.
I hope this helps.

[Christopher Locke]

Yes, those are a little different - no shank (smooth part between the head and the threads). Jamestown does also have deck screws, which are closer to wood screws, but not exactly identical - shank in a deck screw is same or almost the same diameter as the root (the inside of the part where the threads go); true wood screw has shank that is same diameter as outside of threads, so that the shank fills the hole created by the threads. Appreciate your imput, though.

[ 10-20-2005, 07:05 PM: Message edited by: Christopher Locke ]

[Victor]

I have McFeeley's SS square-heads. Be warned, they're really soft!

[jlapratt]

I don't know how they would hold up in a boating environment, but the big box stores carry square drive, 316 stainless deck screws. I use them for outdoor projects and they work fine (so far).

Jeff

[Venchka]

Dunno about the science of it all. John Anderson used several pounds of Robertson silicon bronze screws to hold Elisabeth Grace together. Why? Becasue that's the way he builds boats and he's Canadian. That was good enough for me.

On removing Robertson drive screws: several folks here have mentioned using a soldering iron to melt the goo clogging the square hole. Seems to work.

Wayne
Passing in and out of the Swamp. :D

[ 10-22-2005, 10:19 AM: Message edited by: Venchka ]

[FSS172]

Christopher - Try http://www.fastenal.com. They've got em and they show 10 outlet locations in the NYC area. I've had good experiences with them. They don't have minimum orders, and my local store, at least, is staffed with friendly humans - not the 'whaddaya want' kind of life-forms that seem to inhabit a lot of industrial supply places. Only cautions are to watch for things like rolled vs. cut threads and to watch pricing. Some items are a lot more expensive than marine suppliers yet some are less - even within the same item/material category. Compare their per item pricing on various sizes and lengths of SB carriage bolts to, say, Jamestown Dist. and you'll see what I mean.
Jim

[Christopher Locke]

Jim, thanks, that is a big help. Notice to all who may be interested: Jamestown Distributors sent me an e-mail confirming that they do not carry these screws now but plan to add them within the next 3 months.

I'll probably buy some silicon bronze and some stainless steel; if I'm having problems with the silicon bronze I can always switch. Thanks to all for their advice and information - I've really learned a lot.

Chris

[Alan Peck]

My thoughts:
First, the square drive screws are great, I did not have a single instance of the bit jumping out and marring the surrounding wood out of close to two thousand screws. Regular slot screws drive me crazy trying to keep the driver in the slot.

Second, if it is going to be below the waterline, whether fiberglassed or not I would use the Silicon Bronze screws instead of stainless.

Third, I have tried both the tapered Fuller type drivers and the step drills. I found better fit using the step drivers and the built in countersink is very handy. I also, like the combination drivers and countersinks that Makita sells. I think you can even find those at Home Depot.

Fourth: Out of the 2,000 bronze screws, I only broke maybe six. I think the secret was the step
drills and the fact that I used a battery power drill that had an adjustable clutch to drive the screws. With the adjustable clutch, I could set it to the torque needed to drive the screw but no more. Worked great! It doesn't have to be an expensive dril (mine was just a 12V Black & Decker), but it needs to be one with the adjustable cluth. I don't think my wrists could have held up to hand driven and the little battery powered screwdrivers don't have the strength to hold up.

Fifth: Other people more experienced than I have strong ideas that may differ from the above observations. But, the above worked great for this amateur. One final thought, even expensive screws are a small part of the total cost, don't scrimp here.

[Christopher Locke]

Alan, thanks for your thoughts. I don't care about cost, only convenience. Where did you buy stepped drill bits? I looked at Makita but their bits appear to just be a normal bit with a countersink, which isn't the same thing. Fuller sells stepped bits but you have to specialty order them. I know that it is important to match them to individually sized screws but I'm surprised that someone doesn't just make a large variety so that you can pick the right one for each size screw.

I have now bought some silicon bronze plus tapered bits from Jamestown Distributors and plan to also buy a few stainless steel from one of the other places indicated above just in case the silicon bronze don't work out. I'd love to pick up some stepped drill bits if I can. Thanks for any imput you may have.

[ 10-25-2005, 10:27 AM: Message edited by: Christopher Locke ]

[Christopher Locke]

For the benefit of anyone interested, being unable to find a manufacturer of "off the shelf" step drill bits, I contacted W.L. Fuller to order custom drill bits. They responded by sending me several pages of their new Catalog 25, to be released shortly, which now has standard size step drill bits for standard wood screws. So nice when that telepathic link between me and the manufacturers works! The prices range between about $10 for a 1" #8 and $20 for a 2" #10. If anyone else is interested, you can contact W.L. Fuller and I'm sure they'd be happy to send you the relevant pages of the new catalog. For some reason, their e-mail address is stepdrills@bitsnbores.com, which seems to be the online seller for W.L. Fuller. Good luck, and thanks again to all of those on the forum who have furthered my education.

Chris

[Paulyboy]

I prefer to use screws with rolled threads and size them one size larger on the diameter than screws with cut threads. a tapered drill does a nice job for those types of screws.[/QB]Good point. Another advantage of tapered bits is when using really hard woods. All the outdoor furniture I build using oak is assembled with this combo of tapered bits and the aforementioned screws.

[Jay Greer]

One fact that often is often overlooked is that screws with a full diameter shank and cut threads have a distinct advantage in marine use. When used in combination with Fuller Taper Bits and Counterbores, I believe the best possible holding power is achived. While the full size head serves to hold components together, the property of the full shank, serves to resist sliding of the planking in a fully planked hull. As a hull twists in a seaway, the full shank screw is superior to those with rolled threads and undersize shanks both in strength and by the fact that the shank is in full contact with the sorrounding wood. Cut threads drive more easily and cleanly than rolled ones do. Dipping the tips of fastenings in melted bee's wax makes fastenings much easier to drive. The wax insulates the screw some what from corrosive tannins and electrolyosys potentials.
Bee's wax is also a fungicide and prevents rot from forming around it. This is another reason why it is used to fill the pocket beween the bottom of the garboard and keel sides. I prefer driving screws with a Yankee Driver for greater sensitivity. Once you learn to use it, you won't the have problems most amature builders complain about.

[ssor]

Sometimes when the wood is very hard I will use a hardened self tapping sheet metal screw as a tap in the pilot hole then remove that and put the bronze screw in. This is recommended in some of the old cabinet making books when installing brass hinges in oak, fasten with steel screws first and then put in the brass.

[arcticship]

For tnose interested in the superiority of the Roberston screw, and of screws in general I would highly recommend the book One Good Turn - a natural history of the screwdriver and the screw by Witold Rybczynski, Harper/Perennial Canada ISBN 0006386032.

[batory]

Have you heard of Spax screws?
They are available here:

http://www.leevalley.com/hardware/page.aspx?c=1&p=41315&cat=3,41306

or here: http://www.spax.com/usa/spax.htm

batory

[sdowney717]

How good is the durability of 316 SS in a cool salt water environemt where wood is partially submerged off and on versus constant underwater submersion?
How practicably durable is 316? Does anyone have examples where proven 316 screws crevice corroded?
I have seen plenty of destroyed 304 305 SS screws but have no experience with 316 underwater.

[sdowney717]

http://www.nickelinstitute.org/index.cfm/ci_id/11021.htm

The nickel institute says for ss in a seawater environment to be resistant to corrosion you must use 'super-austenitic 6% Mo grade or a super-duplex such as 2507'. But does anyone make such screws??, I sure have not seen any. Perhaps these grades are available to the govt and we are left out. But I would think there would be a market for a ss screw immune to corrosion in salt water. And if they were truly immune they woyuld be better than bronze or monel, I have not seen monel screws available either.

More Info from the site
'This formula shows the beneficial effect of chromium, molybdenum and nitrogen and illustrates why Type 316, with 2-3% Mo, has better resistance than Type 304 to marine environments. However, for resistance to corrosion when immersed in seawater on a longterm basis, it is necessary to move up to a grade with a relatively high PRE number, such as a super-austenitic 6% Mo grade or a super-duplex such as 2507.'

[donald branscom]

Does anyone know of an on-line distributor of square drive (Robertson) stainless steel wood screws? A number (e.g. Jamestown) have square drive wood screws but only in silicon-bronze, not stainless steel. Many others have stainless steel screws but not square drive. Still others have square drive stainless steel screws but not in wood screws! The big home improvement places like Home Depot and Lowes do not appear to have them either. I know from friends that some local hardware stores do carry them but I've surveyed all hardware stores near where I live and they do not stock them. Thanks for any suggestions.

Christopher Locke

[ 10-18-2005, 11:10 AM: Message edited by: Christopher Locke ]

The heads snap right off all the time. Check it out.