Keeping the Chuck on the mill

[S.Nickens]

I didn't even consider the possibility that you would be trying to mill with a Jacobs chuck. Ginger is right, doing this is a very bad approach, not to mention dangerous. End mills should always be mounted in the correct size R-8 collet. I know everybody has a budget, but you can start with a popular size like 3/8"or 1/2" for less than $20, and add to your collection as funds become available. An eight piece set will run you around $160 ( 1/8" - 1" by 1/8", most std sizes ), and you can always check E-Bay. SAFETY FIRST!

[ChuckDickerson]

As others have indicated it it a very bad idea mill with end mills in a drill chuck. The drill taper is not designed to hold with a side load. It is designed to drill (up and down) so the forces press the drill chuck onto the taper when drilling. You can get a set of R8 collets very inexpensively from ENCO (www.use-enco.com).

6pc R8 collet set DD231-4606 currently on sale for $19.95
11pc R8 collet set DD231-4611 on sale for $36.95
23 pc R8 collet set DD231-4624 on sale for $77.95

The $20 6pc set should serve you well and be much safer than milling with a drill chuck.