What is the definition of "positive-negative rake angle"?
An insert and toolholder combination that creates an effective positive rake at the grooved cutting edge of the insert but an overall negative rake for the insert and toolholder.

Learn more about positive-negative rake angle in the class Toolholders for Turning 260 below.


Metal Cutting Training


Class Information
Tooling U classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:Toolholders for Turning 260
Description:This class explains the components and identification of OD and ID toolholders used on the lathe.
Prerequisites: 200240  200250 
Difficulty:Intermediate
Number of Lessons:14
Language:English, Spanish

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Below are all the competencies and job programs that contain the class Toolholders for Turning 260. Job programs are our traditional class lists organized according to common job functions. Competencies are our latest job-specific curricula that help tie online learning to practical, hands-on tasks.

Click on any title to view its details.

Competencies


Class Outline
  • Objectives
  • The Importance of the Toolholder
  • OD Toolholders
  • Parts of the OD Toolholder
  • Clamping Methods
  • Toolholder Rake Angles
  • Toolholder Lead and Cutting Edge Angles
  • OD Toolholder Designations
  • ID and OD Toolholder Similarities
  • ID Toolholder Deflection
  • ID Toolholder Chip Clearance
  • ID Toolholder Designations
  • Modular Toolholders
  • Summary
  
Class Objectives
  • Describe the role of the toolholder.
  • Describe OD toolholders.
  • Identify the parts of an OD toolholder.
  • Describe toolholder clamping methods.
  • Describe toolholder rake angles.
  • Identify lead and cutting edge angles.
  • Interpret OD toolholder designations.
  • Distinguish between ID and OD toolholders.
  • Describe ID toolholder deflection.
  • Describe chip clearance for an ID toolholder.
  • Interpret ID toolholder designations.
  • Describe the role of modular toolholders.

Class Vocabulary

Vocabulary TermDefinition
carbide A common tool material that is very hard and wear resistant. Indexable inserts, toolholder seats, and boring bars are all commonly made of carbide materials.
ceramic A hard, brittle material that can withstand high temperatures. Ceramic cutting tools require high cutting speeds and rigid machinery.
chipbreaker A feature designed to prevent chips from forming into long pieces. Chipbreakers are either indentations on the surface of the cutting insert or another wafer clamped above the insert in the toolholder.
cutting edge angle If viewed from above looking down on the cutting tool, it is the angle formed by the end flank of the tool and a line parallel to the workpiece centerline. Increasing the cutting edge angle tilts the far end of the cutting edge away from the workpiece.
facing An operation performed on a lathe that feeds a cutting tool across the end of a cylindrical workpiece to shorten its length.
ID operation An operation performed on a lathe that machines the interior of a cylindrical part. Drilling and boring are common ID operations.
indexable insert A cutting bit that has multiple cutting edges. Once a cutting edge is excessively worn, it can be indexed to another edge, or the insert can be replaced.
inscribed circle A circle that fits exactly within the boundaries of another shape.
lead angle If viewed from above looking down on the cutting tool, it is the angle formed by the side flank of the tool and a line perpendicular to the workpiece centerline. A positive lead angle moves the side flank into the cut, and a negative angle moves the side flank out of the cut.
left-hand tool If viewed behind the tool down the length of the toolholder, a tool designed to cut from left to right.
modular toolholder Specialized tooling consisting of a back end mounted in the turret and interchangeable front ends containing various cutting inserts. Modular tooling allows quick and accurate positioning of cutting tools on the lathe.
OD operation An operation performed on a lathe that machines the exterior of a cylindrical part. Turning and facing are common OD operations.
offset shank A toolholder shank with a head that is positioned off the centerline of the rest of the toolholder.
pocket The recessed section at the end of the toolholder into which the seat and cutting insert are clamped.
positive-negative rake angle An insert and toolholder combination that creates an effective positive rake at the grooved cutting edge of the insert but an overall negative rake for the insert and toolholder.
profiling An operation performed on a lathe that feeds a cutting tool along a non-linear path to create conical or curved features in a cylindrical workpiece.
rake angle If viewed from the side facing the end of the workpiece, it is the angle formed by the face of the tool and a line parallel to the floor. A positive rake angle tilts the tool face back, and a negative angle tilts it forward and up.
right-hand tool If viewed behind the tool down the length of the toolholder, a tool designed to cut from right to left.
seat The small wafer clamped underneath the insert in the pocket that supports the insert during machining.
shank The long, rectagonal section of the toolholder that is clamped into the turret.
straight shank A toolholder shank with a head that is symmetrical to the length of the entire toolholder.
tool geometry The collective angles formed by the dimensions of a cutting tool that make a tool unique.
toolholder A tool used to rigidly hold a cutting insert in place during machining. Toolholders are classified so that they can be paired with the correct style of insert.
turning An operation performed on a lathe that feeds a cutting tool along the length of a cylindrical part to reduce its diameter.
turret The component of a lathe that holds a number of cutting tools. The turret rotates to place tools in the cutting position.