On Jun 24, 6:56 am, Ray K wrote:
RicodJour wrote:
On Jun 23, 9:46 pm, Ray K wrote:
Yes, the screws I used for testing have flat heads, somewhat like sheet
rock screws. I could countersink the holes to prevent this problem.
Wouldn't I also have to countersink for pan head screws to get them
flush with the lumber?

A countersink is tapered, such as used for drywall and flat head
screws, and it creates a wedging action as the screw is driven home.
That is what's causing the wood to split. A counterbore for a pan
head screw would have a flat bottom. That provides a clamping action
and won't wedge the grain apart.
http://en.wikipedia.org/wiki/Countersink
http://en.wikipedia.org/wiki/Counterbore

Thanks for the excellent points. I had been thinking that if I don't
overtighten, a countersink would be okay. But with regard to the effort
involved, countersinking or boring would be equal.

At this time, I'm thinking of using a #4 pan head screw, 1.5 or 1-5/8
long, with a pilot hole the complete length of the screw and a
counterbore. Sound okay?

You could also use stainless steel finish washers and eliminate the
counterbore. The flat head screw would still sit proud of the
surface, but it might satisfy your aesthetic requirements.
http://www.jamestowndistributors.com...oduct.do?pid=1...

I prefer that the screw head be flush or below the surface.

Thanks,

Ray

Stick with #6's .....4's are too small. I would suggest a very
coarse thread like a drywall screw but not drywall screws

like this


www.mcmaster.com
part number
92325A309
Sharp Point Thrd-Form Screw for Plastic 410 SS, Pan Head Phillips,
6-13 Thread, 2" Length
In stock at $8.34 per Pack
This product is sold in Packs of 50

or

93406A158
Large Dia (Truss) Head Phil Sheet Metal Screw 18-8 SS, No 6 Size,
1-1/2" Length
In stock at $10.63 per Pack
This product is sold in Packs of 100

but it's only 1.5" long