The bronze is a bit harder to machine than aluminum although it takes a
wonderful surface finish. Much softer than steel.

If you are using a standard drillpress and just have a few pieces, make
a 'V' block of aluminum or wood, center punch, and drill. If you need to
make a hundred or more, make a small fixture with a drill bushing above
the part. Look for a "flanged drill bushing" in the right size at McMaster.

You don't say how many you will need but once you get to the couple
hundred or so range, check with a smaller local CNC machine shop. This
part is so easy it begs to have the new guy do it for training. I'd also
suggest that your supplier is marking them up by at least 400% to 600%.

pogo wrote:

I looked through McMaster, found SAE 841 bronze sleeve bearings for $.62
each part number 6391k178. They have the same thing in steel, just not
quite the right wall thickness.


How easy is bronze to drill, compared to aluminum? Harder ? Harder than
steel ?
Thanks !