Abstract: A twist drill having a longitudinal axis, a shank portion sized and shaped to be grasped by a twisting tool, and a barrel portion for cutting a workpiece. The barrel portion has a number of flutes formed therein spiraling about the axis and terminating at a point end of the barrel portion. The point end has a number of point surfaces including an inner flank surface, an outer flank surface, a groove surface positioned between the inner and outer flank surfaces and a split surface. The inner flank surface extends from the center of the point end to the inner extent of the groove surface and the outer flank surface extends from the outer diameter of the point end to the outer extent of the groove surface.
Abstract: A stand for a bicycle that supports it at an angle. The stand includes a single elongated member which attaches to the bicycle at two locations by means of a slotted member which encircles the crank spindle and a yokeless shoulder member which supports a chain stay to support the bicycle. The opposite end of the elongated member serves to contact the ground. The stand is readily installed and removed, and is stored in a second location on the bicycle when the bicycle is in use.
Abstract: A twist drill having a longitudinal axis, a shank portion sized and shaped to be grasped by a twisting tool, and a barrel portion for cutting a workpiece. The barrel portion has a number of flutes formed therein spiraling about the axis and terminating at a point end of the barrel portion. The point end has a number of point surfaces including an inner flank surface, an outer flank surface, a groove surface positioned between the inner and outer flank surfaces and a split surface. The inner flank surface extends from the center of the point end to the inner extent of the groove surface and the outer flank surface extends from the outer diameter of the point end to the outer extent of the groove surface.
Abstract: An improved tap has a thread cutting portion over which there is a Titanium nitride coating. The Titanium nitride coating has a Rockwell C hardness of at least 70. The body portion of the tap underlying the Titanium nitride coating has a Rockwell C surface hardness of at least 65. This enables the body portion of the tap to provide a rigid support for the Titanium nitride coating. Due to the interaction between the Titanium nitride coating, the relatively hard body portion of the tap, the number of flutes and the cutting face hook angle, the number of holes which can be tapped with a straight fluted tap is increased from 114 to 1,461. On a spiral pointed type tap having a relatively hard body portion interacting with the Titanium nitride, number of flutes and cutting face hook angle, the number of holes increases from 1,662 to 4,758.