Pi Harvester Chain Sharpening

Chain Sharpening Recommendations: 

  • We recommend sharpening to the specifications found in Table 1 below. Grinding at a vise rotation angle of less than 30 degrees will result in reduced cutting performance. 
  • Pi Harvester Chain is designed to be round ground. Square grinding will result in reduced cutting performance. 
  • If heavy grinding is required to get past a damaged spot we recommend a heavy grind followed by a finish grind in order to minimize burr formation and maximize sharpness.
  • Keeping the tooth cool is very important for all chains. Heat will affect the heat treat in the steel and reduce its ability to hold an edge. Pi Chain is much more heat resistant than other chains but heat is detrimental to any grinding application.
  • We recommend grinding with a liquid coolant.
  • If grinding without coolant take light grinds and try to always keep the tooth cool enough you can touch it after grinding. 
  • Pi chain is best ground with a CBN wheel of 80 or 100 grit. These wheels last a very long time, do not need to be shaped and only need cleaning with a dressing stone. 
  • Aluminum Oxide grinding wheels can be used to sharpen Pi Harvester Chain but the wheel will wear quickly and will need to be reshaped frequently. 

 

Table 1: Chain Grinding Recommendations

Wheel Width Vise rotation angle Down angle Head tilt angle Depth Gauge (Raker height)
5/16 inch 35 degrees 0 degrees 50 degrees 0.06” to 0.07”

 

What is a burr?

  • When the chain is sharpened a small lip of metal forms at the cutting edge. This lip of metal is called a burr.
  • Most burrs will come off in the first few cuts.
  • If you want to remove the burrs before using your chain we recommend a small foam block that has a piece of 100 to 200 grit sandpaper on it.

Burr formation is a part of the sharpening process. A burr means the edge has been fully sharpened. Below are a few drawings to illustrate burrs. 

 Diagram showing how a heavy grind results in a larger burr. Depicts removing a burr from a cutting edge with a sand paper foam block.

Chain storage

We recommend that the chain be stored every day in a way that does not allow for the formation of rust. Maintaining the chain well oiled is an excellent way to prevent rust. Rust will significantly reduce the life of the chain.

 

 

How to remove burrs from a harvester chain: