Thread Milling

Just curious, but why would you want to mill threads in aluminum? Unless something has changed, thread milling usually is applied to materials that are difficult to thread with a conventional tap.

That, and thery don't make thread mills for that small a size as far as I know. I've used a lathe thread boring bar as a single point thread mill. They are cheap on ebay, etc.

Karl

Emuge makes them down to 0-80!

Jon

You can get single-row thread mills that will do a range of thread pitches. They are still expensive, but about half the price of one standard thread mill, that can only be used on one thread pitch. I got one made by "Micro 100" they are sold by most of the major tool distributors.

Jon

The main reason for think of using the thread mill is because my old Hurco does not have an encoder on the spindle to do rigid tapping, and I don't have any experience, (yet), using the floating tap holders that came with the machine. The rigid tapping looks like it will work close to the blind hole bottom without switching tools, ie. standard tap followed with a bottoming tap...

That's a good reason. In fact, we had an application or two at Wasino, using our multi-axis turn/mill machines, in which milling threads just simplified the total operation.

You missed out the other main use for thread milling:- Threads that are large enough for the tap to be a serious amount of money compared with thread milling :-)

Mark Rand RTFM

Looks like Emuge has a pretty neat thread mill that drills the hole, mills the threads, and puts a relief groove at the bottom of a blind hole in one shot.

I haven't seen that one, but Emuge makes very nice tools.

Some years ago one of my customers was working on a design for a pizza vending machine. Being involved with them in solving some mechanical issues, the owner wanted to give me a lucrative contract for some of said parts. I contacted an engineer at Emuge and inquired as to how fast one of these could make a 1/4-20 hole .500 deep in extruded aluminum.

I don't recall the specifics of the reply but assuming a 10k spindle and adequate coolant, I seem to recall about 3 seconds total. Sure looked like a winner to me, saving hundreds of tool changes a day.

Sadly, the project never went to production.

Jon