counter sinking screws

[rayclar]

Hi all, noob here as far as allunium goes. I have to countersink some flat head screws in 1/4 inch allunium and would like to know the easiest way of doing it. I have limited metal working tools but lots of wood working tools. Any help would be appreciated. thanks ray

 

[Haywire]

If you don't want to spring for a countersink bit you can use a drill bit the same diameter as the head of the screw. The taper won't be exactly right, but it'll get the job done as long as your material isn't too thin. Test on scrap first of course.

Ian

 

[SandburRanch]

A 7 flute rose counter sink would be my choice but they are more difficult to find than lesser 3 fluted. As mentioned, a twist drill can be used and to give a better fit it can be ground to the correct angle. In either case, if possible, use a drill press with a depth stop and the work clamped to the drill press table.

All good wood workers have a counter sink don't they?

 

[rayclar]

yes i have wood counter sinks 5 flute, just did'nt realize i could use them on aluminum. What speed should i set the drill press at ? thanks all

 

[SandburRanch]

yes i have wood counter sinks 5 flute, just did'nt realize i could use them on aluminum. What speed should i set the drill press at ? thanks all

Somewhere less than a speed for hickory like maybe try around 500 to see how that works. By the seat of the pants guessing here.

 

[Baby Grand]

Shouldn't be a problem using the wood CS. Aluminum transfers heat so fast you'd really have to lean on that drill at high speed to over heat it. Like Sandbur says, using a drill press rather than a hand drill will give you much better results - less chance of "pentalobbulating" with the 5 flute CS.

 

[RoyJackson]

I suggest a countersink. They aren't that expensive. A countersink stop would be nice, but only if you have a lot of usage for one.

Most flush screws use an 82 degree countersink...but not all. Some are 90 degrees (these are included angles, BTW). A typical drill bit has a 119 degree included angle.

I wouldn't countersink aluminum sheet less the .06" thick and definitely never countersink if .04" or less. That thin sheet should be dimpled.

 

[Shield Arc]

yes i have wood counter sinks 5 flute, just did'nt realize i could use them on aluminum. What speed should i set the drill press at ? thanks all

If you happen to have a little kerosene, dip the countersink in it before cutting the aluminum.

 

[SandburRanch]

"pentalobbulating" .

I tied a wheel weight to a clothes pin, clipped the pin to my tongue, let the weight dangle and still can't pronounce that word.:laughing:

 

[SandburRanch]

If you happen to have a little kerosene, dip the countersink in it before cutting the aluminum.

I had forgotten about that. Thanks