Ignoramus10114 fired this volley in
news: snipped-for-privacy@giganews.com:
What's the application? The 8-32 would be a stronger bolt, with more
thread cross-section. But it may not be necessary for whatever you wish to
hold.
L
Ignoramus10114 fired this volley in
news: snipped-for-privacy@giganews.com:
PS... a lot of heat-sink _component_ mounting hardware comes in M2.5x.45
size, for mounting things like TO-3 and TO-220 packages. That's smaller
than 6-32.
L
Ignoramus10114 fired this volley in
news: snipped-for-privacy@giganews.com:
Then one sizes it according to what you want to mount.
I mentioned 2.5x.45 metric... some also use 3 x 0.5mm, but even that's
smaller than 6-32.
If you need to mount through screw insulators (like for mounting a
transistor or a floating-case regulator like an LM-317, you may be hard-
put to find any insulators that will fit even 6-32... metric has more-or-
less filled that market.
Lloyd
Either would work, assuming the aluminum is thicker than 1/16 inch..
you never want less than two threads.
Be sure to check/flatten the machined surface (I sometimes rub it down
with a whetstone) if there's any deformation, or the flat-to-flat
heat transfer interface will be compromised.
That has little to do with it. Except for construction and
transportation equipment, it's mostly a matter of whether the industry
is heavily involved with science, in which case US fasteners are
metric fasteners, just as they are everywhere else, or if it has an
international supply chain.
It's useful to look at three markets: the market for off-road
equipment (mining, construction, etc.); the market for automobiles;
and the market for electronic devices.
In the first case, the issues are that the market is truly global and
that the equipment has to be repairable around the world. Thus,
Caterpillar was the first large US company to go 100% metric, beck in
the '70s.
In the case of automobiles, US-built cars have never had much of a
global market but they are now the end of a global *supply chain*. It
is cheaper, and more flexible, to use metric fasteners for US-built
cars, when they may be built from parts supplied by 20 different
countries.
Electronic devices are designed and built in an environment that is
close to the underlying science, where metrics have been the lingua
france in the US for most of a century. Metrics are followed in the
engineering and in the assembly; repair is a miniscule economic issue.
Also, the supply chain is not only multinational, but also ad hoc; you
may not know this week where your parts will be coming from next week.
The upshot is that, with 70% of our economy based on domestic
consumption, there is little or no economic advantage to making
sweeping changes to metrics in other industries. Thus, change is slow.
And it has little advantage for anyone other than those industries
described above.
whit3rd fired this volley in news:07594162-52db-470a-
snipped-for-privacy@googlegroups.com:
That would truly be a sin on a nicely anodized heat sink!
If it's not flat, it's junk anyway, I guess.
Lloyd
6-32 works fine. I do these often. A good, sharp tap (not the horrors from
the local hardware store) work quite well. I use "Alum-Tap" from Wibro as a
tapping fluid, it is incredible stuff. Makes the tap go in like it was
already threaded.
Jon
Jon Elson fired this volley in
news: snipped-for-privacy@giganews.com:
Oh, I don't know... if I want a 'standard' straight-fluted tap without
having to wait, Hansons are pretty good quality. 'Never got a dull one,
nor one not accurately-cut. They cut freely and don't leave any more
burrs than any other reasonably well-made tap.
I prefer spiral-flute taps for most work, because about 3/4 of my stuff
is blind holes; but there's nothing wrong with a Hanson tap. That's what
ACE carries - carded, one per. I don't know about your local hardware
store.
LLoyd
LLoyd
The dollar percentage of durable goods sold in the US and made in the
US was 66.6% in 2010. The overall percentage of dollar value of
consumer imports, in all categories including oil, was 11.5%, of which
the actual cost was 7.3%. The remaining 4.2% goes to US
transportation, wholesaling, and retailing markups.
If you follow US manufacturing and trade for a decade or more, you'll
realize that almost every popular conception about our manufacturing
and trade is wrong.
6-32 is a course, ie nc, thread. 8-32 is a fine thread, ie nf. The fine
threads do less cutting relative to the screw's major diameter.
The 8-32 will be less likely to break than the 6-32 which, in steel, is
a consideration. In aluminum probably either one would free of worry.
Maybe the 8-32 would be a little freeer.
Hul
Ignoramus10114 wrote:
"Ignoramus10114" wrote in
message news: snipped-for-privacy@giganews.com...
I've never had a breakage problem with good-quality 6-32 taps in
aluminum, if that's your worry. If possible I use two flute spiral
point (gun) taps in through holes and kerosine etc for the lubricant,
and I don't start the tap without some sort of squareness guide,
either the mill or a hand-held fixture like this:
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.