[TowerTalk] Tapping or cutting copper
Its from Onion
aredandgold at msn.com
Wed Aug 19 04:59:25 PDT 2009
Bacon fat or lard is best. If you use milk then clean everything
nearby as soon as you have finished, milk splashes stain and rust steel
Use a very sharp (or roll-form) tap, and some arrangement to keep the
tap vertical is almost essential - a drill press or the like will do at
a pinch. Without some such arrangement it is very difficult to tap
copper, even a slight misalignment from vertical will cause the tap to
When (dry-) turning or drilling copper I find high speed helps, but
that's a bit impractical when tapping.
As with all tapping, a slightly oversize hole will make life much easier.
As to taps, carbon taps are plenty sharp and hard-wearing enough, but
HSS taps are tougher and break less easily - and toughness counts,
especially if you are hand tapping and aren't using a tapping machine or
drill stand etc. to keep the tap absolutely vertical.
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