SonexBuilders.net

Just noticed in the new Yard Store www.yardstore.com catalog that they have double margin piloted drill bits in size 3/8" with 1/4' pilot # 17966, and 5/16" pilot # 17967 at $10 each. Not familiar with use of double margin bits, and cannot say they are good for drilling the wing bolts or not, and no length is listed so may not be long enough, but at only $10 anyone looking for bit for this might want to check it out.

David A.

Have used this type of drill bit to do the wing rigging, we had a drill kit that we sent around the country but unfortunately the kit got lost in the mail.
The 4 cutting bits make a beautiful finished hole, perfectly round and almost like it was reamed. No problems with wallowing the hole like a standard 2 flute pilot drill.