Q What blade do you suggest for a radial arm saw so the saw does not pull into the wood being cut?

A If the saw is pulling into the wood, then you are using an incorrect saw blade for this saw. I suspect you are using a saw designed for a table saw; you need a blade designed for a radial arm saw.

Let me give you a little background information. Start by drawing a straight line from the tip of the tooth to the center of the blade (we would call this line a radius). Then, look closely at how the bottom of the tooth (about 1/4 inch below the tip) is located with respect to this radius line. Is there a slight gap between the bottom of the tooth and the line? If so, then we say this saw has a positive hook angle. The hook angle is the angle between the tooth and the line, which might be on the order of 10 degrees or more. If the line and the tooth do not have a gap but line up perfectly, then we say that the tooth has zero degrees of hook. Finally, if the base of the tooth protrudes beyond the radius line slightly, then we say that the saw has a negative hook.

A saw with a positive hook will try to pull itself into the wood (or the wood into the saw). We would use a positive hook blade on a table saw for example or a rip saw. With a negative hook, the saw pushes the wood away. On a table or ripsaw, the negative hook design means the wood will fly back at the operator.

Now consider the radial arm saw. If the saw has a positive hook, it will pull itself into the wood as you cut, which means the operator has to use a lot of effort to keep the saw from feeding too fast, and if we had zero hook the saw could be pulled into the piece being cut by the operator. However, we know from experience that a slight negative hook for the radial arm saw (maybe 3 to 6 degrees negative) will work best. The operator will have to use a little effort to pull the saw into the wood, but the saw will not pull itself. This is a safe procedure. 

But let me repeat that such a saw blade used on a table or ripsaw will push the wood away from the blade toward the operator, so do not use a negative hook for those saws. Use a positive hook angle otherwise, you may experience kickback.

Consider the “portable” electric saw. Do we want it to pull itself into the wood? No! So again, zero or negative hook, but not too much negative as the saw will be hard to feed and will jump back.

Also, consider a bandsaw — if the saw has a positive hook, then it is pulling itself toward the wood; it might pull itself off the wheels as it grabs into the wood, which is a disaster. So, a bandsaw will have zero or slightly negative hook. Always get a saw blade that has the correct hook angle for the machine you are using. Most blades are clearly labeled.

Source: Gene Wengert, “The Wood Doctor,” trained people in the use of wood for over 45 years. He was extension specialist emeritus at the University of Wisconsin-Madison. Read past columns at WoodworkingNetwork.com.