Larry Jaques wrote:
On Fri, 27 May 2011 17:45:07 -0700, Larry Jaques
wrote:

On Fri, 27 May 2011 17:19:59 -0500, Ignoramus6479
wrote:

There are two kinds of Philips wood screws. The better ones fit the
screwdriver like hand and glove, stay on it and maintain the
direction. The "other kind" do not, they wiggle out and are a huge
pain to use to start holes in awkward positions, etc.

It is not really magic and it is clear why this is the case -- the
philips hole on the better ones is deeper and has a better fit.
http://www.cooperpowertools.com/cata.../TC-100_EN.pdf
Look for Apex ACR bits with the cool ridges. They're tits, I tell ya.


My question is, rather, what is that mating called, if I order wood
screws online at mcMaster-Carr, what should I be looking for?
I'd go with Robertson Square Drives, myself. They cam out far less
frequently than phillips or pozi heads do. Check out McFeely's for
all the sizes. They have new customer specials and combo discounts.
http://www.mcfeelys.com/ (std disclaimer applies/happy user)
Their hardware isn't cheap, but it's well made.

Many manufacturers are building that into phillips headed deck screws
nowadays, too. You can use either driver for them.

Oops, I forgot to add that Torx screws are great, too, but Robertsons
hold on to the driver a lot better than magnets can hold them.



And can twist the heads right off if you let them...

That's why the cam effect of the Phillips in the first place.



--

Richard Lamb
http://www.home.earthlink.net/~cavelamb
http://www.home.earthlink.net/~sv_temptress