#30 and #40. Very useful but require care and maintenance.
Spring tension for instance.
I found several sources for near identical products that are all breakable. Replaceable blades are too expensive for most, especially Burr-away and Cogsdill.
Probably my best success was with the products from panamericantool.com.
1/8 and 3/32 each $75
<ul> <li>Fractional Sizes</li> <li>Shank Size: 1/4″</li> <li>Furnished with double acting blade for burr removal on both the front & back sides of hole.
</li> <li>The inexpensive, replaceable cutting blades can be adjusted to control the amount of edge break.
</li> <li>Spring tensioned blade...
www.panamericantool.com
They also have great choices for reamers, drills, and drill motors. (Highly recommend a 90 degree high speed drill motor. So easy to control by bracing with one hand at the tip. You won’t believe how much better it is at drilling out rivets. )
When you get one, buy a few replacement blades, take it apart, figure it out, set it up the way you like, don’t drop it on the ground. And don’t put it on a hole that is too big. Easily broken. And only half the broken parts are the blades. So then you buy another…. But it saves time.
Hope you aren’t building to save money.