product could be better in 1/2 inch shank but 1/4 inch is not worth buying. Slips out of the router. The shank size is actually 3/16" to 7/32". Also, if you don't have a proper router and table, this bit is dangerous. You need a good table and a variable speed router. You also need a good fence. I have a desktop router table with a standard fence. The router grabs the wood you're working with and shoots it across the room. Caution for buyers