1. Field of the Invention
The present invention relates generally to hole saws and more specifically to a method of treating a hole saw to provide efficient slug removal, which allows a slug to be removed from the hole saw without the use of additional tools.
2. Discussion of the Prior Art
The most common type of hole saw is a cup with teeth formed on an open end, a shank attached to the other end of the cup, and a drill retained in the shank. The drill starts the hole cutting process by providing a pivotal anchor for cutting the hole with the cup. However, an aggravating problem encountered with hole saws is the removal of a hole slug from the cup. Depending upon the material of the hole slug, removal of the slug can be a major challenge. If the material is plastic, the plastic hole slug will heat bond to the inside surface of the cup. There are numerous solutions proposed for removal of the hole slug. The simplest method of slug removal is to form openings in the top and/or side of the hole saw to allow the slug to be pushed or pried out with a tool.
U.S. Pat. No. 5,205,685 to Herbert discloses a hole saw. The hole saw includes an annular ring surrounding a body of the hole saw. The annular ring includes a teflon coating. However, neither the cylindrical body of the hole saw or the cutting teeth are coated with teflon. U.S. Pat. No. 6,857,831 to Davis discloses an I-joist hole cutting apparatus. The cutting apparatus includes a ring and a chord. The outer surface of the ring is treated with a low friction material, such as teflon. However, the groove cutting member is not coated with teflon.
Durability of a saw cup of a hole saw may be tested by cutting a hole in metal, such as steel plate. If the temper of the hole saw cutting teeth is proper, the cutting teeth will survive forming a hole in the steel plate. If the temper of the cutting teeth is not proper, the cutting teeth will fail. It has been found that high temperature baking of a fluoropolymer resin coating spray on a saw cup will result in the temper of the cutting teeth being compromised for use on any type of material.
Accordingly, there is a clearly felt need in the art for a method of treating a hole saw to provide efficient slug removal, which includes a low friction treatment of inside and outside surfaces of the hole saw body, which has been set, but not cured by the manufacturer.