cutting threads in aluminum?

kerosene is what the machinery hand book calls for also use it for milling and drilling. if you only have a few holes or are grinding or sanding use paste wax to keep the wheel from loading up.

 

Soft aluminum is harder to tap than tool quality aluminum. And a good tap is a must.

Also the hole size is extremely important as is getting the tap started straight.

I've alwasy used tap matic never had a problem. The last shop I worked at was starting to use some water soluable stuff to save the environment. But I continued to use tap matic.

Never had a problem with it.

 

I think I agree, extruded aluminum 6061 ect, is stickier than cast aluminum, (tooling plate). I machine a lot of each, although both are easily machined, cast aluminum tooling plate is definately easier to machine than extruded aluminum. Good taps are a must, as said earlier in this thread, I definately recommend chip breaking taps, even for blind holes, clean out the chips and follow thru with a bottom tap. Like said earlier kerosene is very good for both, but I prefer WD -40.

 

Use alcohol both when you drill the hole and
cut the threads
I use it always when i machine some thing
outh of aluminiun leaves a very shiny surface
Wiskey is fine but if you are a cheap bastr you
can use denaturated alcohol

 

I agree,
I use alcohol quite a bit while machining, It is required for my buddies free machine work.

 

I use this all the time and it works fan frickin tastic. I probly tap aluminum 5-6 times a week.

 

The green tapmatic works well.Smells like peppermint.Green stuff not the clear.Backout tap and clear chips after each full turn.New tap a must.Good luck Fedcospeed

 

tap magic for aluminum, I've been machining aircraft aluminum for the last ten years, and I've done a LOT of it, OSG taps, Morse, etc, don't use cheap ones. Never had a problem with fine threads in aluminum either.

 

Spiral taps

http://www.mcmaster.com/#taps/=70req8

 

2 more suggestions:

http://www.relton.com/cutfluid2003.html#a9

http://www.osgtool.com/HY-PRO®-c280.htm

 

Good advice. The rule of thumb is a 1/2 turn for 2-flute taps, 1/4 turn for 4-flute taps.

For tapping fluid, I keep water soluble cutting oil around and mix it up as I need it, the ratio is 50:1 so a little goes a long way. Traditionally, kerosene is good for tapping aluminum, many cutting fluids are based on it. The best thing I've ever used was Alumatap, it might be off the market though due to it being toxic. WD-40 is good in a pinch.

Make sure the hole being tapped has a nice chamfer to it so the tap starts easily. If you have one, use a "tapping block" to make sure the tap stays square as it cuts. I make mine out of 1" aluminum plate and I have a few about 2" x 2" with clearance holes in them. I've seen them made from phenolic and fiberglass too.

Bob

 

Most of the time the tap drills are the same for steel and aluminum. If no one is putting a plug gage into the tapped hole, you can go a few thousands over when cutting steel.

Roll or form taps are best used for through holes and definitely use a bigger tap drill. I have a formula I use, but they're also on some standard tap drill charts. Use a slightly bigger chamfer, as it pushes up a ridge as it cuts. I use roll taps almost exclusively on aluminum up to 1/4" taps. They're really best suited for use with tapping heads and CNC mills.

Bob

 

Yeah, spiral taps have a thinner web that standard taps. I like them in CNC mills, not for hand tapping.

I bought a Tapmatic head some years back from MSC, it came with made in India standard taps. I put them on the side since I use mostly OSG, Bath, Sossmer, etc products. I was down to having no other 8-32 taps and had to finish up a job that had to have the threads checked with a gage. I bit the bullet and the India taps did the job!

Just about anyone in the business has a good collection of specially ground taps used for added depth clearance or less lead for bottom tapping.

Bob

 

I may get lambasted for this one, but I use lanolin-based hand lotion for all of my tapping and most other machining. I sometimes use a wax stick when sawing or milling aluminum. Been doing it for years, and it works fine.

 

Nah, just about anything will work, especially using HAND lotion for HAND tapping. How could you go wrong?

Bob

 

Works good for power tapping, too

 

Spiral taps with 40 to 50 degree spiral flutes made for cutting specific grades "T-5 T-6"are worth the investment if you have alot of holes to tap. Tapmatic makes good stuff.
I use a Snap on Pnuematic drill if i need to. With the right oil and spiral taps and have no problems. with standard / staight taps this would be broken tap disaster!

 

I thought kerosene was used