"Kadomaru PRO" will solve the above problems. "Kadomaru PRO" cuts easily, cleanly and safely. It's easy to use, as there is a guide that makes it easy to fit the corner of the item you want to cut into place, and all you have to do is press the lever with a little force.
eBay
Coating:AlTiN (Aluminum Titanium Nitride) Coated. Features: End cutting design; flare is tangent to radius. Tool Type:Double-Ended Flared Corner Rounding End Mill. We're down to earth, easy to work with people.
eBay
eBay
4X(Corner rounder for cutting corners. and portable, cutting radius 4mm. Stainless steel blade is and neat cutting. ).
eBay
3-in-1 Corner Rounder Paper Punch – Card & Paper Round Edge Cutter. Create perfectly rounded corners with this3-in-1 Corner Rounder Paper Punch, the ideal tool for craft lovers, students, office work, and DIY projects.
eBay
eBay
Shank: 1/4". Colour: As picture show. Add a round over edge to a variety of edges and projects or create small moldings to be used on its own or as part of a molding build-up. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.
eBay
Featuring a 1/8" radius, this tool is ideally suited for producing precise, smooth rounded corners, critical for the aesthetic appeal and functionality of machined parts.
eBay