Elongated Screw Holes

[Joe Mindell]

Hi Guys! I'm new to Sawmill Creek, I've been lurking here for a while and I've been really impressed with the level of conversation here. I'm a relatively new woodworker, self-taught and fitting in project work between my paying gig and looking after two small balls of energy (boys).

For a current project (curly cherry nightstands) I need to join a drawer kicker to a solid wood top. I want to use screws and need to make elongated countersunk holes in the kickers to allow for cross-grain movement. I have had limited success in previous attempts because if I try to drill adjacent holes with a countersink bit the initial hole tends to grab the bit and pull it off-center. I've seen lots of mention of people making holes like this in magazines, but no one ever says how they do it. What do you guys do?

Thanks

[Steve Clardy]

Welcome Joe!!

I usually just tilt the hand held drill sideways, both directions, when drilling the hole.
Drill the initial hole, then tilt sideways with the drill still running.

[Jamie Buxton]

Your mention of a countersink puzzles me. The point about an elongated hole is that the screw should be able to slide sideways. If the head is captured in a countersunk hole, it can't slide sideways. Use round-heads or pan-heads.

I've tried the business of wiggling the drill bit sideways, and in my hands it doesn't work. It makes the hole elongated at the top and the bottom, but not in the middle of the board. The bit kinda pivots there, leaving the hole the same size as the drill.

One solution is to just drill the hole bigger, and use a somewhat larger washer under the screw head.

[Joe Mindell]

Thanks for your responses. I'm thinking that the countersink will be elongated as well, so that the screw can slide along both. I suppose I could counterbore with a router (i.e. elongated hole for screw head and centered elongated hole for screw shank), but that seems rather complicated for a simple thing.

[Dan Oelke]

Depending on the amount of movement you have to worry about - just wiggling sideways and leaving the top as kind of a pivot point will work. The head of the screw will stay in one place and the body will pivot. This only works for small amounts of movement as the screw is fairly rigid and tight into the material being screwed into so you only get as much movement as the screw will bend. But a #6 screw isn't that rigid, and if you are only worry about movement of a 6-8" wide board I haven't had any problems with that (I even countersunk the head too)

[Kent Fitzgerald]

Lee Valley (of course) has a countersink router bit for just this purpose:
http://www.leevalley.com/wood/page.aspx?p=52607

[Cliff Rohrabacher]

Lee Valley (of course) has a countersink router bit for just this purpose:
http://www.leevalley.com/wood/page.aspx?p=52607
Yah what he said:
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</td></tr><tr><td>Any large panel or table top should be secured in a way that allows it to expand or contract without splitting. These screw-slot bits let you create screw slots so that panels can be held in place but are able to slide back and forth without splitting the wood or breaking the screw securing them. Both have 1/2" shanks and are sized for #8 screws, one for countersunk screws and one for counterbored screws.
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Screw Slot Bits
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Diameter
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Depth
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Shank
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A.
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16J11.60
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Countersink Bit
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7/16"
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13/16"
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1/2"
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$26.50
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B.
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16J11.70
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Counterbore Bit
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1/2"
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15/16"
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1/2"
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$26.50
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http://www.leevalley.com/graphics/add2cart.gif (http://javascript%3Cb%3E%3C/b%3E:OpenProdInfo%28%2716J1170%27,%270%27,%2752607 %27,%27%27,%27buy%27,%27%27,%272%27%29;)
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[Joe Mindell]

Boy, that lee valley bit looks cool. And I was just about to put in an order from them....

[Frank Chaffee]

Hey Joe,
Thanks for asking about this!

It remains very difficult for me to imagine a countersunk head woodscrew, a pan head sheetmetal screw or a flat washer sliding back and forth along a taper sided groove or a counterbored slot in wood, seasonally, for very long at all. Any of the aforementioned connecting systems will, in my estimation, dig into the wood and begin to rotate about an axis just beneath the screw head. This will lead to metal fatigue in the screw, elongation of the threads in the connected part, and a loosening at the point of connection.

I am very conservative of materials in the design/ build arena, and I have been studying this very question for sometime before committing C’s of dollars to a +30” wide table top or a dresser where the drawer slides run perpendicularly to the dresser sides. For the wood movement we expect in 12 or 16 inches, and 32 to 48 inches, I do not see the conventionally applied technique as being other than self destructive. … And no, I do not have time tested furniture to deconstruct.

Coming from a metalworking background as I do, it is my inclination to use two thrust washers lubricated with grease for the seasonal movement of wood when it exceeds the smallest fraction of an inch.

Oh wise Creekers, please HELP some to understand how this can be!

Frank