Countersink drilling??? Advice needed

[MilDoc]

I have an excellent set of countersink drill bits, depth stop collars, etc. But I never seem to get it just right. Some screws don't go in far enough and I re-drill, some too much, some perfect.

So ...any thoughts on initial adjustment of the depth stop collar? Or do I just do a try-see-adjust?

And what to do if the CS bit goes too deep and the screw head is sunk too much?

[Hellrazor]

Either trial and error or measure the screw head with a caliper and make the needed adjustments.

[cabinetman]

Paul

I've found several ways to do a countersink/pilot hole. The first is a very basic countersink bit with no drill bit. When that is used, the drill bit can be used after, and pilot at the point in the wood left by the countersink. This is really a redundant step.

The next type is a countersink bit with a drill bit entoda (fancy word I came up with to mean all-in-one). With this bit, they make the cutter for certain size bits, which are for certain size screws. For example, a cutter size and a bit size that pertain to the screw size and type.

Then there is a countersink cutter, with drill bit, and the collar stop. Now this one should give consistancy to the depth of countersink.

I'm using mostly flat head phillips screws, and there is a difference in the screw head diameters of screws that are in close proximity to eachother. For most of my assembly type screws (3/4" into edge of carcass) I'll use either a 2" coarse thread or a 2" sheetmetal (machine type) screw depending on the application. In most brands, the coarse thread head is larger than the SM one.

I don't use a collar stop on my countersink cutters. I don't like the little polishing the collar does to the surface. For me it's a visual judgement call, and is based on getting used to doing countersinks. I don't get 'em perfect each time, but close enough. As for depth, the head of the screw should be seated slightly below the surface. If fill is intended, a deeper bore may be desired to have enough room for the fill.

There are also those that are bored very deep to allow for a plug to be fitted.



A THING OF BEAUTY IS A JOY FOREVER - John Keats

[Warren]

Paul, I take it your not talking of using the DP. I just try and eye ball it when using a drill in the hand. I know that some drills use to have a depth stop on them, or one that could be attached when needed.

I don't know exactly how much room you have when drilling, but a dowel or metal rod taped to the drill could be used as a feeler. When it touched the wood you stop drilling. It's probably the methd I would use if the screws were in a visiible place on the project.

Another suggestion would be a piece of wood with a hole of sufficient diameter to allow the countersink to fit which would be of a thickness which would stop the drill's progress at the depth you wanted.

I've already had my allotment of Guinness for the evening ,plus one, so I don't know how clear this is.

[cabinetman]

Paul

Don't you read your posts? Dee Dee Dee

[LCHIEN]

one thing I don't like about the all-in-one pilot/CS drills is that the bit stop is usually a collar. Drilling lacks enough tactile feedback to tell if you've drill all the way down and also if you drill too hard then you'll polish a ring around the hole as someone already mentioned.
Also drilling with a hand held drill can give you slight off angle holes which given the width of the stop collar can also lead to variations in depth that given the nature of the head/bevel show up as heads above flush.

I prefer to drill these type holes with a drill press, using its drill depth stop, and perfect vertical alignment, for more consistent holes.

[Tom Miller]

My pet peeve about depth stop collars, is that wood chips invariably get jammed between the drill flute and the collar, keeping the collar from coming in contact with the wood.

Regards,
Tom

[sacherjj]

When building something rough, I use the DeWalt all in one bits in a handheld drill, but never use the depth collar. I usually leave the countersink a little proud and draw the screw in to sink the head flush (in softwood or plywoods). I also prefer drill press operation for getting the setting just right on important holes. Then I just work deeper and deeper on one hole until I get it perfect.

[bthere]

My pet peeve about depth stop collars, is that wood chips invariably get jammed between the drill flute and the collar, keeping the collar from coming in contact with the wood.

Regards,
Tom

That is my problem too. I don't even use the stop collars for this type of work.

While I avoid using countersinks in visible areas, I still like them to be flush, or just recessed after tightening. If hand drilling, I usually end up doing the trial and error method, sneaking up on the right depth.

If using the drill press, you have to make sure the wood is uniform thickness and clamped flat. Then you have to trial and error to the right depth for the first hole, then immediately set the depth stop. Try it on the second hole to make sure you don't need to tweak it. It is great if you have a piece of scrap to use for this setup. Sometimes you will have to pitch out a screw that is significantly different than the rest.

[MilDoc]

Great advice all, folks. Thanks.