Why do my countersinks look horrible

[david w]

It could be caused by a dull bit, too much pressure, bit is turning too fast, no lube.

 

[Vaino]

A very low spindle speed is mandatory and having the workpiece clamped securely is also req'd. Having been a tool and diemaker for a number of years, have never had a
"chattered" ctsk. Of course a very sturdy drill press was used and an attached table vise was used. ....Fred

 

[david w]

A very low spindle speed is mandatory and having the workpiece clamped securely is also req'd. Having been a tool and diemaker for a number of years, have never had a
"chattered" ctsk. Of course a very sturdy drill press was used and an attached table vise was used. ....Fred

The drill bit must also be sharp. A little lube never hurt anything either.

 

[FlinterNick]

Lubricate first, then Slow up the speed and depth and then I polish it with conned dowel and 320 paper (backed with duct tape).

But in general, you’d want to use a high quality counter sink set.

Use CLE Line counter sinks.

 

[Pete G]

Use a single flute countersink.

 

[Vaino]

While being a tool and diemaker did 10000s of ctsks and never used any lube....drills yes, ....Fred

 

[The Appalachian]

When someone says "countersink bit" I always forget there are bits out there labeled countersink, and sold as such, and they are absolute stone cold garbage.

Buy a set of centerdrill bits and end your countersinking troubles forever. With these you can achieve a beautiful countersink in metal or wood or anything really with just a battery drill........

 

[The Appalachian]

If this is like what you're using, stop.

Throw it in the garbage.......

 

[#BPBReloadingFFL]

I've cut hundreds of counter sinks with a hand drill and they all come out nice. That includes aircraft canopies- Don't force the cut move slow and less pressure.