Great for blending! NOT FOR FULL PORT

• does work on cast iron or aluminum at a slow speed with lube
• can leave a very smooth finish at low speed
• very versatile 
• Made from Carbide not cheap steel that chips or bends easily

Dave's Take:

This burr is for all skill levels

The 3/8 burr is my go to for finishing up a pocket port where I don't want to fuss with sanding it. I have heard of people porting with it, but it is not meant to shape aluminum. The burr will load up with aluminum no matter how much lube you use in this instance. It is what we use for just blending in a valve job, or cnc port where minimum material is being removed. If you want something to actually move material and a beginner I suggest the 1/2 at a slow speed. 

 Be sure to check out our useful YouTube tutorials on using these burrs!