This restoration is on a 1920s Model B12 "Safety Saw" pneumatic circular saw made by the Ingersoll-Rand Co.. The "Safety Saw" name was in reference to the patented design of the retractable blade guard, one of the first of its kind. This saw runs off of a triple-piston "Little David" motor that Ingersoll-Rand seemed to use in a number of their larger pneumatic tools.

Unfortunately, I could not find any mention of this saw in the literature and therefore it is only an educated guess on how much compressed air this saw need to run.

The saw had many previous repairs that all needed some new attention. The main issue with this item was the completely seized throttle valve and the extra crusty and old grease that had hardened over time.

Once cleaned of grease, repaired, and reassembled the saw would idle when I applied a bit of compressed air from my air compressor which can only put out 90 psi @ 20cfm. The idling is either due to the low flow of air not providing enough force on some valve to completely seal it, or there is a leak somewhere within the saw. Either way, I decided not to fix that issue because an idling pneumatic circular saw sounds AMAZING and I could listen to it all day.

Despite the reduced air flow, the saw still cut just fine and definitely had tons of torque. I'll be sure to use this next time I need to cut a thick wood beam with the most ironically named tool I've restored.

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