What Tool Can You Buy To Slot A Drilled Hole?

slow&rusty · 07-11-2006, 07:28 PM

Gang - I had a custom exhaust manifold made for my old Datsun Z and one of the holes does not quite line up with the head...its close - but no cigar.

I do not want to use a drill bit as they "walk" and always make a mess.

Is there a tool I can buy to make a circular hole into a neat slotted hole without taking it to my machinist?

Thanks in advance!

Yasin

jim72911t · 07-11-2006, 07:37 PM

ummm, a round file?

Not trying to be a smart-ass, but you should be able to elongate the hole with a simple file. It may take some work and test fitting depending on the thickness of the flange, but you should be able to get the job done.

Good luck,
Jim

Edit: you could also use a dremmel or a die grinder with a carbide bit.

craigster59 · craigster59's Garage

Wasn't that the title to a Frank Zappa song?..

PeteT · 07-11-2006, 09:52 PM

Yasin-You could also use a four flute end mill. They will plunge cut just fine and will not wander.
Pete

TerryH · TerryH's Garage

Here's a pneumatic 1/4 inch deburring tool. It won't drill/bore, but slots holes in metal like cutting warm butter.

Z-man · Z-man's Garage

I believe a Dremel tool with the right end bit can also work.

-Z.

RickM · RickM's Garage

A vertical mill would be the cleanest way to do this. Another approach would be to weld the unwanted hole up and start anew with your drill press.

RallyJon · 07-12-2006, 06:02 AM

slow&rusty · 07-12-2006, 06:40 AM

Thanks for the replies guys!

TerryH where did you buy that deburring tool? that looks like it will work perfectly.

Yasin

TerryH · TerryH's Garage

You can buy those bits at any machine tool supplier. The die/air grinder at any tool supplier. McMaster-Carr has been mentioned here a few times and they would be able to provide both. You can most likely find locally for less. Mine are old, can't remember what the investment was anymore, but wouldn't be suprised if it was north of $150 now days.

Someone mentioned Dremmel and that might be the way to go unless you plan on getting some mileage out of a higher investment. Try not to use a fluted style bit as they will try to walk. The double cut design shown in the picture allows for more control.