Engraving tips

Cutters is an all-inclusive term used to describe  the rotating cutting tools used in the engraving operation. Cutters can be  manufactured from high speed steel or carbide and are available in a  variety of configurations for specific applications.

Most standard cutters are available with either a stainless steel  shaft or a micrograin carbide shaft (see below). The stainless steel  shank is less expensive than the solid carbide shaft. The solid carbide  shaft provides more rigidity and is better for engraving in harder  materials such as stainless steel. Both of these types of cutters have  micrograin carbide tips. Therefore, the cutting edge is of the same  quality. All of these cutters are available with a threaded brass knob for  top-loading engraving machines. The knob has a set screw to allow  adjustment of the vertical position of the cutter and to hold it in  place.

Typically, engraving cutters are single-flute tools. This  means they have only one cutting edge. The cutting edge is highlighted in  the picture at right. Note the direction of rotation of the cutter.

While there is a seemingly infinite number of cutter  sizes and shapes, engraving tools fall into two basic categories - conical  and parallel. Conical cutters have an angled cutting  edge and produce a "vee" shaped, flat-bottomed cut. Parallel  cutters have a straight cutting edge that is parallel to the cutter's  axis of rotation and produce a cut with straight walls and a flat bottom.  The width of the cut can be as large as the diameter of the shaft (i.e.  11/64" parallel tool can be made to cut up to .171" wide)

Conical vs. Parallel

Half Round Section Quarter Round Section

Cutters also can be classified as half-rounds or quarter-rounds.  This refers to how the blank carbide shafts are split during the  manufacturing process. Half-round cutters are made from blanks that have been "split"  or "halved" approximately on center through a grinding process. This tool  has a cross-section that is half of a cylinder and is the choice for most  engraving cutter applications. Quarter-round tools are  half-round tools that have a secondary split at 90 degrees to the original  flat producing a tool that has a cross-section that is one quarter of a  cylinder

Half vs. Quarter Round

The full spectrum of cutter types and their effect on  material can be seen below.

Cutting Angle and Included Angle The cutting angle is the angle formed between the cutter's axis of  rotation and its cutting edge. This determines the "V" shape of the groove  produced by conical cutters. The included angle is double  the cutting angle.

Clearance Angle The clearance  angle refers to the angle of the cutting edge with respect to the face  of the cutter. This angle allows for chip clearance, determines how fine  the cutting edge is and is selected based on material properties.

Tip Angle The tip angle is the angle  at the tip of the cutter. Sometimes called the tip-off. Determines the  width of the flat at the bottom of the cut. End Clearance Angle The end clearance  angle is the angle on the back side of the tip that provide clearance  for the tip.

Tip-Off or Tip Width The tip-off refers  to the flat on the tip of an engraving cutter that determines how wide the  cutter will cut. When we refer to tip width or tip size, we are describing  the width the cutter produces at the bottom of the cut. Tip widths  are most accurately .
	measured by doubling the dimension from the cutter's  centerline to the cutting edge. In the sharpening process, material is  removed from the back of the tool to provide clearance, therefore the  dimension across the tip will be smaller than the cut produced. For  example, a .030" cutter for flexible engraving stock will only measure  about .025"