# SPI boring head - $65 (Sacramento, CA)



## MrWhoopee (Aug 31, 2018)

https://sacramento.craigslist.org/tls/d/spi-boring-head/6679190202.html


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## Bob Korves (Aug 31, 2018)

That ad has been up for a long time.  I had some interest in it, and it appears to be little used, but I did not like how close the markings are for .001" increments, and could not guess if it is the old SPI stuff made to high standards, mostly in Europe, or the lower quality stuff from Asia they sold later on.  It sure might be worth a look.  It appears lightly used in the pics.


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## MrWhoopee (Aug 31, 2018)

I'd like to have one, but given the recent and anticipated reductions of resources, and no immediate need, it will have to wait.
In the absence of  a larger dial or different pitch thread, wouldn't the graduation spacing would have to be the same on all of the Criterion copies?
Remember when SPI stood for Swiss Precision Instruments?


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## BaronJ (Aug 31, 2018)

Hi Guys,

That looks like the Chinese one, if it is, you can get a brand new one for very little more, and with interchangeable mandrels.  I have the metric version.  I don't know what it is calibrated in, but it sure ain't mm.

https://www.chronos.ltd.uk/cgi-bin/sh000001.pl?WD=head boring&PN=Boring_Heads_3_Morse_Taper.html#a1711303M

Mine has two mandrels, MT2 and MT3.


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## Bob Korves (Sep 1, 2018)

MrWhoopee said:


> wouldn't the graduation spacing would have to be the same on all of the Criterion copies?


Not if the lead screw was a different pitch...


MrWhoopee said:


> Remember when SPI stood for Swiss Precision Instruments?


I have some of the older Swiss Precision Instruments tools.  Good stuff!


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