A drill has a first main body portion and a second main body portion. The first main body includes a chip discharging surface, a flank face, and an outer peripheral surface. A ridgeline between the chip discharging surface and the flank face constitutes a cutting edge. The chip discharging surface has an auxiliary flute surface provided in a form of a helix around a center axis, the auxiliary flute surface being contiguous to the cutting edge, the auxiliary flute surface being recessed in a direction opposite to a rotation direction of the drill. An auxiliary cutting edge portion has a first end portion and a second end portion. When viewed in a direction along the center axis, a value obtained by dividing the maximum value of the diameter of the second main body portion by the diameter of the first main body portion is 1.5 or more.

The present invention provides a twist drill. A cone portion is provided at a front end of the operating portion, and an exterior surface of the operating portion is provided with a spiral flute for shunting cutting chips. The exterior surface of the cone portion is provided with a plurality of composite cutting blade groups which are sequentially enlarged in diameter from the front end to the rear end of the cone portion. The cone portion is provided with a top blade on the tip. In use, the top blade is used for positioning, and the cutting process is carried out by the top blade and the composite cutting blade groups.

A step drill bit includes a shank and a body having a proximal end adjacent the shank and a distal end opposite the proximal end. The body defines a plurality of axially stacked, progressively sized steps including a first step at the distal end, a terminal step at the proximal end, and a plurality of intermediate steps having incrementally increasing diameters disposed between the first and terminal steps. The step drill bit also includes a plurality of cutting edges each disposed along one of the plurality of steps. Each edge defines a helix angle and a radial rake angle. The radial rake angle and the helix angle of the cutting edge at the terminal step is greater than the radial rake angle and the helix angle of the cutting edge at the first step.

A step drill bit includes a body with a plurality of cylindrical steps of increasing diameter from a front end toward a rear end, a flute extending from the front end toward the rear end, and cutting edges at junctions between each step and the flute. A cutting insert with a hardness greater than the hardness of the body is coupled to the front end portion and at least partially defines a cutting head portion. The cutting head portion includes a center cutting tip, a cutting edge extending radially outward from the cutting tip, a rake face extending from the cutting edge toward the rear end portion, a relief face extending from the cutting edge in a circumferential direction opposite a rotational cutting direction of the drill bit, and a chip clearing recess in communication with the flute, with the rake face facing the chip clearing recess.

A pocket hole jig system is formed of a plurality of jig segments, wherein each jig segment includes a main body having a drill guide and a lock feature that protrudes outward on a first side of the main body and a recess that protrudes inward on a second side of the main body. The system also includes one or more spacers that have a main body of varying width and a lock feature that protrudes outward on a first side of the main body and a recess that protrudes inward on a second side of the main body. Jig segments and spacers may be connected together by inserting the lock feature of a jig segment or spacer into the recess of an adjacent jig segment or spacer. In one arrangement opposing jig segments and/or spacers lock together with a combination of rotational movement as well as sliding movement.

A drilling tool includes a drive assembly with a shank that is configured to couple to a power tool and a step drill bit. The step drill bit includes a body having a proximal end adjacent the shank, a distal end opposite the proximal end, and a bit axis extending centrally through the body between the proximal end and the distal end. The body is defined by a wall extending around the bit axis to define a hollow interior cavity of the body. The step drill bit also includes a plurality of axially stacked, progressively sized steps with a first step at the proximal end and a terminal step at the distal end and a flute extending from the proximal end to the distal end. The flute defines a cutting edge.

A spiral step twist drill bit, including a shank and a cutting portion. The cutting portion is provided with a spiral flute and a body clearance. A tip of the cutting portion is provided with a chisel edge and a cutting edge. A flank face is connected to the cutting edge, and is provided with a spiral cutting groove. A spiral direction of the spiral cutting groove is the same as that of the spiral flute. A slope of the spiral cutting groove is the same as that of the flank face. The spiral cutting groove is configured to divide the cutting edge into multiple segments to form multiple first edges and second edges.

A hole forming device is provided and includes a base platform with a machining area and at least one hole forming component displaceably disposed on the machining area for performing a hole forming machining on a target object, thereby speeding up the production, improving the production efficiency and reducing the labor cost.

Twist drill bit having a cutting tip (3) with a stepped structure, consisting of a shank (1), a guide region (2) and the adjoining cutting tip (3) with a stepped structure, the stepped structure of which is interrupted by two flutes (5) winding about a drill bit axis (0), wherein the cutting tip (3) with a stepped structure has a drill bit tip (3.1) with a radius (r.sub.o), at which a pair of first main lips (4.1) are formed, and a multiplicity of coaxially arranged cutting steps (3.2), which each have a conical step portion (3.2.1), in which in each case a pair of further main lips (4.2.sub.a-4.2.sub.m) are formed, and a cylindrical step portion (3.2.2), wherein the cylindrical step portions (3.2.2) have, towards the shank (1) , an increasingly large radius (ra.sup.-rm), wherein the difference between in each case one of the radii and the next one of the radii (Ar) is chosen such that, upon rotation about the drill bit axis (0), the pair of further main lips (4.2.sub.a-4.2.sub.m) arranged therebetween sweep in each case over an annular face (A.sub.a-A.sub.m), coaxial with the drill bit axis (0), on an imaginary plane (E) arranged perpendicularly to the drill bit axis (0), and the annular faces (A.sub.a-A.sub.m) have an identical surface area, such that, during drilling, an identical chip volume is carried away with each pair of the further main lips (4.2.sub.a-4.2m).

A drill may include a base. The base may be extended from a first end to a second end. The base may include a first part, a second part, a step, a first cutting edge, a first flute, a second cutting edge and a second flute. The step may be located between the first part and the second part, and may have a larger outer diameter as coming closer to the second part. The first flute may be extended from the first cutting edge. The second flute may be extended from the second cutting edge. The step may include a first step and a second step. The first step may connect to the first flute. The second step may connect to the second flute. A first end part in the first step may be located further away from the first end than a second end part in the second step.