"Beryllium" is generally actually a BeCu alloy only about 2% Beryllium and the rest copper with sometimes minor amounts of other alloying metals.
Beryllium Copper is stronger than most bronze alloys and is, or was, the metal of choice for tools in a spark free environment.
BeCu is also commonly used in plastic injection molds as the heat transfer is almost as good as pure copper but the strength is exponentially higher.
Pure Beryllium is rarely used in common industries, as far as I know, but it does show up in lab and experimental work, such as the atomic lab at Argonne Illinois.
Pure Beryllium DUST is the hazard.
Special precautions must be taken when grinding pure, or high percentage Beryllium but it does not come up much in the 'real world'.
BeCu alloys, such as the wrench above and most other common industrial settings are not particularly hazardous.
BUT, since pure Be can be a carcinogen, (if inhaled), our present social environment has resulted in somewhat of a stigma for BeCu.
Most applications have Be free alternatives available, that are not as efficient, but do satisfy the sticklers.
The suppliers have more than ample proof that BeCu is not hazardous, but they have yielded to public perception and offer the alternatives.
BeCu is still the alloy of choice for mold makers.
Sometimes you just have to keep your feet on the ground in a real world.
You will NOT get cooties by picking up that wrench!
Unless, of course, you melt it down, extract only the Beryllium, cool it off, grind it without liquid coolant, and snort the dust.
The flywheel wrench is likely a bronze. I have borrowed one such in the past.
The one I have now is Aluminum. Strong enough and cheaper.
