What Are Helical & Bickford Drill Points?

Drill Point Features

• All drill points, including Helical and Bickford, have four primary features: point angle, cutting lips, lip relief and chisel edge. Point angle refers to the angle of the actual front of the drill bit, with higher angle points better for hard materials and low angle points for softer materials. Cutting lips are the beginning of the flutes which extend form the point; typically these are straight. Lip relief typically refers to the angle at which the cutting lips move away from the point of the bit. The chisel edge is the connection between the cutting lips, the most forward point of the drill bit.

Helical Drill Point

• A Helical drill point has a slight protrusion at the very front of the bit, and uses an S-shaped chisel edge. The chisel edge and protruding point serve as a self-centering element by allowing the front of the drill to penetrate the surface and stick before drilling begins. Helical drill points also have a continuous cutting edge, beginning at the center of the drill and blending into a curving cutting edge. This feature distributes the energy of the drill more evenly than conventional drill points (which use a straight chisel edge) and is known to reduce chipping.

Bickford Drill Points

• Bickford drill points use an S-shaped chisel edge for self-centering purposes, similar to a Helical drill. Unlike Helical points, which have a short, straight edge from the cutting lips back, Bickford uses a feature similar to the Racon drill point, a longer radius from the cutting lips, created to reduce grabbing material when exiting a hole. Bickford drill points use a structure similar to Helical points, but place a greater emphasis on reducing wear on outer corners and exiting curved or angled materials cleanly.

Advantages

• Both Helical and Bickford drill points demonstrate an advantage over conventional points, which have a straight chisel edge. The S-shaped chisel edge plate forces equally across the point, rather than beginning in the center and moving outward, which reduces burr when first drilling into a material. Similarly, Bickford drill points in particular are known for minimizing burrs at breakthrough points, unlike conventional points, which require manual removal of burrs once the drilling is done. The self-center feature of Helical and Bickford drill points also makes for an extremely accurate hole.