Hi Sam
It looks like it was done with a Shaper cutter, the key is the 5/8" deep(slot) cut.
They are made for 1 3/8" to 1 1/2" thick stock,but they will work on 3/4" thick stock some comm. wood shops just use one type of cutter for all the doors they make.
It looks like the items below but they make many types just like the ones that fit in routers with a 1/2" shank, But the norm is 3/8" to 7/16" deep slot on most of the R & S sets.
You can some times get around this by using the R & S sets WITHOUT the bearings and just use the fence as the guide but it will take a pass or two to get it right on the button (5/8" deep on both parts)
Note***the bearings on most R & S sets is a spacer as well so to say if you remove the bearing you will need to put in a spacer, sometimes the lock collar on some router bits works fine for this but the set screw must be down inside all the way or to say flush or you can use/get AN/NAS/MS flat washers.
C2172 Entry Doors 6 pc. Stile & Rail Set - Quarter Round, 3/4" Bore
http://www.grizzly.com/products/c2172 http://www.grizzly.com/products/c2175 http://www.grizzly.com/products/cate...spx?key=162300 http://www.grizzly.com/catalog/2007/Main/514
Bj
