SpeTool Spiral Router Bits with UpCut 4 inch Extra Long1/4 inch Cutting Diameter 2 inch Cutting Length CNC Router Bit Carving Tool

Needed to create several 2 deep, 1/4 wide dados and thought this bit would do the job. Because this bit is so long I was concerned that the bit would be prone to breaking as some have reported. I tried a 1/4 deep pass (typical for shorter bits) but the chatter was too great. I reduce the cutting depth to 1/8 and chattering was still unacceptable and the dado cut was not clean. I finally decided, using 1/8 depth of cut to do a series of multiple plunges (ie used the bit like a drill bit) across the length of the dado (roughly every 1/4). This serves to hog out a lot of the material but puts no lateral stress on the bit. I then came back after the drill cuts and used the bit normally to remove the rest of the material. There was little to no chatter at this point as much of the wood had already been removed. It was slow and tedious but the resulting dados were flawless.

Needed this to cut multi later birch plywood 1.5 thick. Just went down in 1/4 steps and it cut fine. Because of its long length just go slower than you usually would with a short bit . Longer bits tend to break if you apply too much force. Great bit for the price and cut better than I expected very clean edges.

Use in my cnc for 1.5 inch pine and while cutting multiple passes all stayed aligned.

Went to make a test cut on a half inch thick piece of wood and the bit snapped within 30 seconds.

I have never used a bit this long before. I was having some problems controlling it. I suspect control would come with time.

Even taking very shallow cuts (~ 1/8) this bit did nothing but chatter. This left a horrible shoulder on my mortise. I switched to using a shorter bit from whiteside for the first portion of the cut, and it cut like butter. I am glad this mortise will be hidden, because otherwise this bit would have ruined my project.