The cutting edge design of Pi harvester chain incorporates a nickel superalloy coating with carbide reinforcement which contributes to the spark reducing effect. 

There are three primary factors that contribute to spark reduction.

1. Nickel sparks tend to self extinguish rather than burn which means a spark that is generated quits burning more quickly compared to one generated from a conventional chain.
2. The coating on the cutter teeth has a lower coefficient of friction which means less heat is generated between the tooth and the rock which means fewer and less intense sparks are created.
3. The cutting edge is hard enough to cut into the rock which carries away some of the heat with the rock dust. 

Keep in mind that this chain is spark-reduced not spark-free so all precautions you currently take to avoid fires need to be taken when running Pi harvester chain. Also keep in mind that there are other sources of sparks and fire ignition besides striking rocks so Pi harvester chain is one small improvement to everything else you are already doing to stay safe in the woods.

Sparking intensity is significantly effected by the type of rock. A basalt rock for example as is common in the Pacific Northwest has a very high sparking potential whereas a soft rock such as limestone has very little potential to generate sparks.