37mm  Diameter JEI Solutions Turbo Endurance magnetic drill bit cutter with 50mm Cutting depth.

These cutters are also known as Annular Broaching cutters 
 

With their unique centerfree design, JEI Solutions Turbo Steel HSS-Cobolt cutters cut only the periphery of the hole, ejecting the remaining center as a slug.

These cutters produce reamed quality, burr-free holes in one operation, eliminating costly pilot holes and step drilling. JEI HSS-Cobolt cutters reduce torque and horsepower requirements by only cutting the periphery of the hole using the proper tooth geometry.

Used in conjunction with 1/4" long Pilot ejector pin .

Drill holes 3 times faster than twist drills.
Drill unique and curved surfaces.
Allow overlap cuts on existing holes.
Produce reamed quality burr-free holes.
Coolant fed cutting edges.
Produces solid slug.
Reduce machine size and horsepower requirements.
Manufactured with C.N.C. accuracy.
Resharpenable cutting edges.
Eliminate time consuming, costly pilot holes and step drilling.

With universal shank 19.0mm
internal bore 6.35 mm
Steel quality : special quality high speed steel with cobalt
Ground section : high performance toothing with pre and post cutter

Suitable for many brands of equipment including :

ALFRA Rotabest ( Weldon )
ALFRA Roata-Quick quick change system
BDS
Bux
Ruko
Evolution
Magnetor
Euroboor
Universal
Nitto
Jancy
Jei Solutions 
Hougen
Magtron
Promac
Rotabroach
Slugger

As well as all types of Magnet Drilling Machines with a 19mm Weldon shank.