Todays metalworking

Today I needed to make an extended nut with a tee handle to screw a compresson fitting to a product we make to pressurize it and do a leak test.

Our old line has a compression fitting nut that looks like it was brazed to a cylinder of

360 brass. Not sure if filler metal was used. Then a couple of pins at the far end to implement a tee handle.

I didn't like it. I obtained some fittings and decided to use a chunk of 1/4" pipe with a taper cut to match the taper on the brass fitting. I also looked up the liquidus values for some silver brazing wire we have and the 360 brass the fitting is made out of.

Silver brazed using Harris black flux and some 40% silver brazing wire. That went well. Any tips on getting the flux off other than wire brushing?

Then I needed to add the tee handle. I thought about drilling holes 90 apart and adding two pins. Then I decided to just stick a long rod though the cross drilled holes and chucking up the pipe and using a two flute end mill to cut out the center area where some

1/4" tubing has to pass.

I *thought* the 1/4" round stock for the tee handle was low carbon steel. Guess it wasn't.

After I brazed the tee handle in, I tried a 2 flute HSS end mill in a drill chuck on a 22" swing lathe drilling into the end of this thing clamped in the chuck. Wiped out the end mill instantly. I guess that tee handle stock was not low carbon steel. Oops.

Found a 8.5 mm carbide drill in my tool box and used that to drill through. Went through easy. Mystery metal can bite you some times. The strange thing is I brazed in the tee handles and went to lunch. I'd have thought air cooling would have left the tee handle fairly soft.

Wes

Reply to
Wes
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Well, I guess you picked on a piece of air hardening tool steel. Us blacksmiths use H13 and S7 for chisels, punches, etc.. I think they have to cool from critical to about 1000°F at a rate of 10° to 25° per hour to get a full anneal. I just got done with some correspondence about Atlantic 33 tool steel. You can harden that one by quenching in water or by just throwing it on the floor to cool.

Pete Stanaitis

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Wes wrote:

...Then I decided to just stick a long rod though the cross drilled holes and

where some

chuck on a 22"

Went through

Reply to
spaco

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