Wednesday, September 18, 2013

Bandsaw Gullet Crack Followup


Not long ago I recorded some observations in the Bandsaw Blade Crack Failure post.  Yesterday I replaced a broken blade and took a couple of images to illustrate another point.

When I noticed the saw arm starting to move up and down with each blade rotation I knew a crack had formed.  I tried to get the blade out intact but it snapped all the way in the process.  I laid it on a swage block and marked it with a presto pen to highlight what I wanted to standout.

The image is a poor one but is good enough to record this point - the complete break is several inches away from the weld area.  The other point is that there is a secondary crack on the other side of the weld area a bit further away that the primary failure crack.  Intuition tells me that these are too far away from the weld to be a heat-effect phenomenon but this is a  bimetal blade and that may be a special case.

Frankly, I haven’t paid close enough attention in the past to note whether this is a consistent pattern, but I’m tuned in now and I’ll report what I find.




No comments:

Post a Comment

I don't often check for blog comments, so the best way to contact me is directly: at ottercreeksmith@gmail.com or djedwards@cableone.net