Something else to remember is that more flutes = less material in the tap itself. Not much material there if you look at the cross section of the broken tap is there? Never try to "power tap" with a 4 flute tap. Hand tapping only.
You will be amazed at how much more torque a spiral point 2 flute tap will handle and how much easier they cut compared to the same size 4 flute tap. Even brand spanking new ones.
Starting with a 4 flute plug tap is also problematic. I have was taught that to tap blind hole (not your case, ML) as deep as possible, one should start with a starting tap, second stage with the plug tap and finish with the bottoming tap.
Although, I admit, I have gone from starting to bottoming taps without using the plug tap, it's a "do as I say, not as I do" sorta thing.
Well back from a little three day vacation trip and back out in the shop today. First finish tapping the plugs without breaking any more taps. [
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Next drilled the fence to accept the plugs.[
attachment=6152][attachment=6147][
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Next welded the plugs in place and ground off the welds.
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And finally a shot of the complete horizontal longitudinal fence on the sander.
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Next will be building the horizontal cross fence tomorrow.
M.L.Woy
They just don't make sanders like that anymore. Nice job on the fence.
Ed
(08-21-2013, 09:14 AM)Highpower Wrote: [ -> ]I don't especially like the smell of WD-40 myself, but like Tom I use it by the gallon when it comes to machining aluminum / aluminium because it is cheap. I can pour it on without worrying about breaking the bank. I have heard that straight kerosene works just as well though. Anyone tried that? 
There is only one lubricant for tapping Aluminium, and it might sound a little odd, cheap hand cream, that's right, no-name generic skin moisturiser, go into the Missus' stash steal the cheapest looking bottle and give it a go, it stays where you put it, lubricates much better than WD40 or Kerosene smells nice and even makes your hands feel nice, the only drawback is when you run out you have to go into the cosmetics department to buy more and it feels a little foreign especially when you are all set up in your finest tapping attire complete with shavings in your hair.
I had a machinist working for me in 2002 and it was his "Secret formula" he used to bring it in from home in an unmarked squeezy bottle, I recognised the smell as the cream my Mum used to use it while watching TV every night after washing the dishes.
I asked and he couldn't very well lie about it when asked, He didn't last too long with us but I've been using his secret formula ever since.
Regards
Rick
PS tomorrow's tip; how to stop your high heels getting caught in cobble stones
(09-01-2013, 06:27 PM)Rickabilly Wrote: [ -> ]...PS tomorrow's tip; how to stop your high heels getting caught in cobble stones
OK Ed - we now need a "Dear Rick" column...
