Treated Hardwood Plugs 3/4" x 4". 1 Box/500 Plugs per Box. For Drill Bit size 11/16". Poles, Inc. offers a large variety of treated hardwood plugs for sealing inspection and treatment holes. We package our plugs in convenient 1 gallon and 5 gallon containers. Treated hardwood plugs are generally 1/16” larger in diameter than the drill bit size that was used when drilling the hole. Note plug packages are filled by weight and volume calculations and counts should be considered to be estimates. Special Order Only.