[Elecraft] Countersinking screws

[Jeremiah McCarthy]

Countersinking screws in a home shop without the proper tools can be frustrating...If you have a drill press and can securely clamp the panel so that it cannot wander, you might succeed...Even so, the bit itself can flex and chatter, resulting in a triangular hole...Feeding the bit into the cut very slowly helps, but it is no guarantee that it will not chatter...

It is next to impossible to countersink holes using a hand held drill motor even if the panel is clamped in a vise...The cutting angle of twist drills is not necessarily uniform...It depends on the hardness of the material they were intended to drill into...Bits bought from surplus clearing houses are sometimes sharpened to odd angles...

In industry, countersinks have a smooth pilot-pin protruding from the center of the cutter that is the same size as the screw hole...The pilot bears against the sides of the hole and keeps the countersink from wandering...These tools have from 4 to 6 cutting edges, resulting in smooth cutting...Twist drills only have 2 cutting edges and no pilot and this causes chatter...These countersinks have a built in adjustable depth controlling device...If you do not cut deep enough, the screw will protrude above the panel...If you cut too deep, the screw will seat below the surface of the panel and you will have a silver ring of bare metal showing all around the screw head...

I would not advise trying to countersink the screws in your prized K-2 unless you have the tools and the skills...

Jerry, wa2dkg