What single profile thread mill to tap 3/8-16 hole?

[figure1a]

I have a Roland MDX-540 which from talking with Roland the only way to tap holes with it is to use a Single Profile Thread Mill. I want to tap 6061 aluminum. When I go to a site like MSC:

Single Profile Thread Mills - Thread Mills | MSCDirect.com

there is a ton of data for each thread mill but I don't know how to decipher which thread mill to use to tap a 3/8-16 hole. Anyone know?

[holbieone]

3/8-16 tap -> 5/16 (.3125) drill

if you brake it down and think about it , the chart is easy to use

you need the cutter dia. to fit in the drilled hole plus have enough cutter to cut the thread you need

the chart tells you the max and mins for thread per inch (this will not change for the dai.)
so as long as you have a cutter that will fit in the hole and can cut the thread you need you will have a cutter you can use

[dak1]

A single profile tool will take a lot longer to thread. I'd use a multi-profile tool.

Helical Flute Thread Mills - Thread Mills | MSCDirect.com

[figure1a]

A single profile tool will take a lot longer to thread. I'd use a multi-profile tool.

Helical Flute Thread Mills - Thread Mills | MSCDirect.com

With the Roland, you can only use the single profile. Do you know which thread mill I would use to make a 3/8-16 hole?

[figure1a]

3/8-16 tap -> 5/16 (.3125) drill

if you brake it down and think about it , the chart is easy to use

you need the cutter dia. to fit in the drilled hole plus have enough cutter to cut the thread you need

the chart tells you the max and mins for thread per inch (this will not change for the dai.)
so as long as you have a cutter that will fit in the hole and can cut the thread you need you will have a cutter you can use

Thanks, but that's not what I am asking. I am looking to figure out which single profile thread mill will make a 3/8-16 tap.

[dak1]

With the Roland, you can only use the single profile. Do you know which thread mill I would use to make a 3/8-16 hole?

Please axplain why. You are simply cutting a helical arc. Single tooth simply reuires more arcs than multi tooth. What am I missing?

[rowbare]

It can't be simpler than that page on MSC. You have two parameters to deal with, size of hole and threads per inch. Select any "Minimum Nominal Diameter" less or equal to 3/8" as a starting point, then look at the resulting list to see what the minimum threads per inch is. If it is less or equal to 16, you are good to go.

Either the SPTM240/SPTM240L or SPTM290/SPTM290L would work.

bob

[rowbare]

Please axplain why. You are simply cutting a helical arc. Single tooth simply reuires more arcs than multi tooth. What am I missing?

The Roland spindle probably doesn't have enough power to drive more than a single point cutter.

bob

[holbieone]

Thanks, but that's not what I am asking. I am looking to figure out which single profile thread mill will make a 3/8-16 tap.

So you only read the first line of my post ?

[dak1]

I've never had to worry about power requirements on a thread mill, but I'd be hard pressed to believe a multi tooth thread mill reuires more power than the tap drill.

[dak1]

Do you want to tap the hole or thread mill the hole. (2 totally different processes).

[figure1a]

Please axplain why. You are simply cutting a helical arc. Single tooth simply reuires more arcs than multi tooth. What am I missing?

The MDX-540 is a small CNC mill. The spindle only goes one direction so I can't use a regular tap like on a drill press with a drill tap rig that reverses the tool out one the hole is tapped. So I need to use a single profile (or point) thread mill that carves the thread into the hole.