Looking for short extra-flat head M3 screw, countersunk

...

would do).

McMaster-Carr stocks non-metric flathead machine screws with 100 degree countersinks. Closest to M3 would be #4 or #6. A 6-32 100 degree countersink screw has a head thickness of 0.060 inches.

They also stock 82 degree degree "flat undercut" heads with non-metric threads. The head thickness on a 6-32 flat undercut screw is only

0.059 inches.

Check out

you can get technical drawings of most of the fasteners.

Tim.

Thanks, it helps, although I do need metric.

M

do).

You might need an "undercut" flat-head screw.

What's amazing about screws (in the US at least) is that they are ordered by long-winded description, not by part number or some other orderly manner. Only MS (mil-spec) screws have accurate part numbers.

Call San Jose Screw Company. They answer the phone "SJS"

John

John Lark>You might need an "undercut" flat-head screw.

That would be a *really* long-distance call from Slovenia. 8-)

I am looking at these, too, yes, as a last resort. I have a sample here that's not undercut, but don't know the source. Its probably about 100 degrees.

M

Not much longer than say from Italy. And shorter than say vienna :)

Its weird to order metric screws from US but if that's the only place I can find them at I will. Need a few thousand of these.

M

do).

100 deg is standard for metric. 82 deg is standard for imperial.

do).

Can you countersink the panel below the cover slightly to accept the standard fastener?

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what\'s the reason?
For if it prosper, none dare call it treason."

"Follow The Money"  ;-P

fastener?

Unfortunately not.

M

do).

I have had no problems using standard flat head screws in fastening

16 gage sheet metal. So the countersink angle goes all the way thru the thickness, just add the difference / excess in countersinking the receiving base. No big deal.

sheet metal.

difference / excess in countersinking the receiving

Due to construction of the base this isn't possible.

M

Which is NOT always possible.

fastener?

Why? is the panel below made of diamond or similar matrerial?

:TheM wrote: :> I'm looking for something like this: :> :>

:> :> The only gotcha is that I need the head extra flat, that is the angle :> of countersink needs to be as high as possible (I believe 100 or 120 deg would do). :> I believe standard screws on sale everywhere are 82deg. :> :> I need to screw down a thin cover and regular screw head is too thick. :> :> Mark :> :> : I have had no problems using standard flat head screws in fastening :16 gage sheet metal. : So the countersink angle goes all the way thru the thickness, just :add the difference / excess in countersinking the receiving base. : No big deal.

If the base material is reasonably thin itself, and threaded to take the fastening screw directly, then countersinking will reduce the thread depth at the very least. Where a clinch stud is used to provide the base material fastening, countersinking will cause the stud to become detached and there will be no means of fastening.

do).

--
I\'ve noticed references to 114 degree metric flatheads, but I wasn\'t
able to find anyone who sells them.

100 degree flatheads are fairly common (and cheap) in American sizes
so maybe, if your spec\'s aren\'t written in stone, you could
substitute?

http://fairwayfasteners.com/display.asp?id=475 

JF

You can either believe me when I say it is not possible or spend

1000EUR and fly here for the "Oh, now I get it" moment :)

Mark

Something like that, yes.

M

I've noticed and considered that, yes, even the undercut screws I've found are all imperial sizes. Still, that is plan B. Haven't given up on M3 yet.

M

fastener?

Think about it. If it is too thin, then countersinking would kill (read break) PEM attachments, etc.