Taper-Point Drill Bits

[Brian Penning]

I guess I don't quite understand how to use these bits correctly.
If I hold the bit up against the applicable screw with the screw end even with the drill bit end the only amount of thread I see is just a small amount where the drill bit tapers. The rest of the drill bit is a larger diameter than the screw itself including the threads.
When I insert the screw into the drilled hole it drops down except for the previously noted protruding amount of thread surface length.(maybe 1/2"). In the photo it looks like the drill body is too big for the screw to me. Before these bits came didn't the diameter of the drill bit for the receiving wood part supposed to be the diameter of the screw shank?
Am I missing something?
http://www.leevalley.com/images/item/woodworking/drilling/07j0502g2.jpg

[Don Bullock]

Brian, I have the same question. I understand that the screws I ordered from McFeeley's don't need a taper bit. That makes me even more confused.

[Alex Berkovsky]

Also awaiting patiently for an answer. I also have a set and had to drive #8 screw but the corresponding tapered bit was wider that the screw. I used a #4 bit instead. :eek:

[John Bush]

In softer woods I use a non-tapering countersink drill and in hardwoods I use the tapering. I snapped a few screws off before I got the tapering set. The first set I bought were the Cheapies and as you could imagine, The drill bits snapped too. I'm not sure which brand I have now but cost more and haven't failed. JCB

[Kyle Kraft]

I don't fully understand the question, but when using screws to assemble two workpieces, generally you would want a countersink and clearance hole in the upper piece and a "tap drill hole" in the lower piece. The reason for this is if the diameter of the hole in the upper piece is too small, the threads could bite into the material and jack the upper piece off the lower piece slightly before the threads grab in the lower piece. This would cause a gap in the assembly.

Make sense?

[glenn bradley]

It's the type of screw you're trying to use, eh?

From McFeely's:

"Cut thread is oldest way of making screws. Cut thread uses a larger diameter wire and cuts material away to for the thread. Cut threads generally require use of tapered drill bits proper holding power. Rolled thread uses smaller wire and rolls the wire through dies to squeeze the threads onto the shaft. Rolled threads produce threads proud to the shank of the screw. These tend to hold better and can be used with a standard pilot hole drilled with a straight bit."

[Don Bullock]

It's the type of screw you're trying to use, eh?

From McFeely's:

"Cut thread is oldest way of making screws. Cut thread uses a larger diameter wire and cuts material away to for the thread. Cut threads generally require use of tapered drill bits proper holding power. Rolled thread uses smaller wire and rolls the wire through dies to squeeze the threads onto the shaft. Rolled threads produce threads proud to the shank of the screw. These tend to hold better and can be used with a standard pilot hole drilled with a straight bit."

That being said, I still don't know which drill is best for:

https://www.mcfeelys.com/images/diysampler_freeship.gif

It doesn't say what kind of thread these have.:confused:

[glenn bradley]

Watch for McFeely's "Screw Testers Wanted" cards that come in the mail now and then; 200 screws and a #2 bit for $10. If you don't get the mailer, I'd call or email them and ask about it. None of the screws in the sampler I mention are cut-thread.