Metric Wood Screws - info and sources please

[harryn]

Hi

For various reasons, some of them actually useful, I am gradually shifting my hardware over to metric. As I increase the amount of machining I do from basic hand tools to more threading, etc, it potentially will save me $'s to just have to buy taps, dies, and screws of fewer sizes for every day use, and then just the specific ones I need for those other jobs.

For my general purpose Al around the house projects, I am using M1.6, M3, M6, and M12 in fine thread, as these are pretty handy sizes, step changes, and correspond approximately to some useful US fractional sizes. I am still debating on a size in between M6 and M12.

I am lost on what to do with wood.
- Is there such a thing as metric wood screws roughly equivalent to the size 6, 8, and 10 screws in the US ?
- How about the various dry wall and deck screws ?

Given the poor quality of most home center wood screws, I increasingly use deck screws which are hardended and more rust protected.

I buy most of my metric fasteners from mdmetric.com, as even though they some 3,000 miles away, they have better selection and prices than the local stores. Perhaps someone can suggest some more options.

BTW, yes, I realize that it is kind of crazy to use metric wood screws in the US, but it has both an educational and sometimes convenience aspect.

Suggestions ?

Thanks

Harry

[youngjim]

Umm.. I understand the difference in using either metric or imperial for metal parts, but if you're screwing a deck together, does it matter that they're #8 or #10 versus 2 or 3mm? Don't get me wrong, its personal preference, but from an engineering standpoint, is there a functional difference?

[High Seas]

Nice -- but expensive wood screws -- Fearsons -- they are like philips but don't tear out the slots - and the shank is the size of the minor diameter. You can get them -- mind you, more expensive, in BRONZE - better than ss/carbon steel/galvanized etc.

Try Mcmaster-Carr or Jamestown Distributors (google)
Jim

[harryn]

Hi, actually - no it doesn't.

We have a bit of a problem here with "normal" screws (and nails) in general, esp. wood screws - they are junk. This does not mean they are out of spec, they are just made from such soft alloys that they barely withstand the process of being put into wood. I am not talking about oak, I am talking about typical home depot quality 2 x 4s. If I put them in by hand, the head can often survive the process - but even with very modest use of a power screw driver, they fail. The heads are more like Al then steel.

Nails are even worse - I have stopped using them for any and all projects. My hammers are now virtually unused, compared to when I grew up, and nailing was the norm.

The only wood screws I can buy locally with a chance of working at all properly are high end deck screws. This is ok, but not always the right choice to build with, esp finishing projects.

What I have noticed, is that the metric screws I purchase in general are much higher quality - both in tolerance control and alloy. What I am hoping, is that if I can find metric wood screws, they will exhibit similar improved quality. I also really don't like having a mixture of metric and imperial size parts on a drawing / sketch. I suppose if it were CAD, it does not matter, but I still do most of this with a quick pencil and paper, and it is just handy to stay within one system.

It is not a big deal, but since I am now doing more projects with my 10 yr old son, it is nice to avoid the extra complication of conversions, on top of everything else that is going on with building something.

Thanks

[ger21]

These are what I use. Very high quality, but not the cheapest. The only wood screws I've used for the last 10+ years. Their website is a pita, but they send catalogs monthly once you order.
http://www.mcfeelys.com/product/0822...ry-Lube-Screws

[youngjim]

Ok, I see where you're coming from now. Are you using philips or robertson? Robertsons seem to be more durable, and if they do get stripped, you've got a nice round axial hole for a left-hand cobalt drill bit and a screw extractor.

[harryn]

Hi, Thanks for the tips.

I mostly used philips - have not seen robertson's around here, but probably just need to look more closely.

The latest deck mates at HD are a sort of star drive - looks sort of like a torx to me.

The metric screw question is also a bit for my own education. I was under the impression that Canada used the metric system - so would also have some kind of metric wood screw. - right ?

[youngjim]

Originally Posted by harryn Hi, Thanks for the tips. I mostly used philips - have not seen robertson's around here, but probably just need to look more closely.

P. L. Robertson wouldn't license the design to Henry Ford, so thats why Philips is more common in the US, lousy design for a fastener or not.

Originally Posted by harryn The latest deck mates at HD are a sort of star drive - looks sort of like a torx to me.

Those are better, you just have to be careful to keep your tool square to them.

Originally Posted by harryn The metric screw question is also a bit for my own education. I was under the impression that Canada used the metric system - so would also have some kind of metric wood screw. - right ?

You'd think We're somewhat bilingual on the issue, #10 screws into 2x4s, but you have to drive no more that 80 Km/h down the road to go get them. Bizarre, huh? Jim