Witness holes

[mildot1]

I already searched!

How do you prevent or remove the burrs from drilling magazines for witness holes??? Is there an EASY way to get it done?

Thanks

Mildot

[TreblePlink]

Go to any decent industrial supplier and ask for a de-burring tool. Machinists use them every day. They look like kind of a curved knife, with a swivel handle. Might set you back $3.99. Push it into the hole, spin it, you're done. Using lubricant, a sharp bit, and proper pressure when drilling can often reduce burring.

[Toolguy]

It's a good idea to have a deburring tool and a mill file. Magazines are made of spring steel. Drilling with a regular drill bit leaves big

burrs that take a lot of work to get rid of. The best way to go is to drill a pilot hole about 1/2 the size of the finish hole. Finish drilling the

hole with a 4 flute ball nose end mill. Use a slow spindle speed (200 - 400 rpm) and light feed pressure. You can do it with steel tools,

but they wear out fast. A carbide spade drill and a carbide end mill will last a lot longer as long as you don't chip the cutting edge. The

best way to do this is in a mill where everything is held rigid. With the ball end mill you will end up with thin feathery burrs that can easily

be removed with file and deburring tool.

[mildot1]

Thanks for the input.

I do have access to a mill, so I will go that route.

It's a good idea to have a deburring tool and a mill file. Magazines are made of spring steel. Drilling with a regular drill bit leaves big

burrs that take a lot of work to get rid of. The best way to go is to drill a pilot hole about 1/2 the size of the finish hole. Finish drilling the

hole with a 4 flute ball nose end mill. Use a slow spindle speed (200 - 400 rpm) and light feed pressure. You can do it with steel tools,

but they wear out fast. A carbide spade drill and a carbide end mill will last a lot longer as long as you don't chip the cutting edge. The

best way to do this is in a mill where everything is held rigid. With the ball end mill you will end up with thin feathery burrs that can easily

be removed with file and deburring tool.