On Sat, 2012-08-18 at 12:09 -0400, John Kasunich wrote: > > On Sat, Aug 18, 2012, at 10:59 AM, Kenneth Lerman wrote: > > On 8/18/2012 9:49 AM, Gene Heskett wrote: > > > On Saturday 18 August 2012 09:46:26 Kenneth Lerman did opine: > > > [...] > > >>> I have done quite a few 6-32 holes in 7078-T6 but can't claim a lot of > > >>> experience in tapping the common alu stock sold at Lowes/TSC, its > > >>> pretty soft. ISTR the last batch of 4-40's I tapped about 3/8" deep, > > >>> blind, took about 4 trips back out to clear the chips. Not much chip > > >>> room in a common hand tap. > > >> Try using roll form taps. They don't generate chips. > > >> > > >> Regards, > > >> > > >> Ken > > >> > > > Do they not require near breakage torque and EP lubricants? > > > > > > Cheers, Gene > > I've only used them in aluminum and never broken one. I usually brush > > the tap with a little motor oil. I don't know what is recommended. > > My understanding is that you need to drill a slightly larger hole > for form taps. Trying to use standard tap hole sizes leads to > breakage. (Haven't used them yet, just bought a few last week > because I got tired of picking chips out of blind holes.)' > > I usually use gear oil for tapping - it has high pressure > additives.
There are easily available formulas for calculating the size hole to drill for form taps. Some people recommend reaming the hole to get it just right. Talking to the reversing tap driver manufacturer in Post Falls, ID they recommend an EP grease for tapping. Ought to work well for forming taps also. Dave ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
