Thread Rolling 101

Thread Rolling Definitions

  • Class of Thread: An alphanumerical designation to indicate the standard grade of tolerance and allowance specified for a thread.
  • Crest: The top surface joining the two sides of the thread.
  • Depth of Thread Engagement: The radial distance, crest to crest, by which the thread forms overlap between two assembled mating threads.
  • Helix Angle: The angle made by the helix, or conical spiral. Of the thread at the pitch diameter with a plane perpendicular to the axis.
  • Major Diameter: The major diameter is that of the major cylinder-distance across the crests of the thread.
  • Minor Diameter: The minor diameter is that of the minor cylinder-root diameter of the thread.
  • Nominal Size: The designation that is used for general identification of a thread based on the major diameter.
  • Pitch: The axial distance from a point on one screw thread to the corresponding point on the next screw thread. Pitch is equal to the lead divided by the number of thread starts.
  • Pitch Diameter: On a straight screw thread, the diameter of an imaginary cylinder the surface of which would pass through the threads at such points as to make equal the width of the threads and the width of the spaces cut by the surface of the cylinder. On a taper screw thread, the diameter, at a given distance from a reference plane perpendicular to the axis of an imaginary cone, the surface of which would pass through the threads at such points as to make equal the width of the threads and the width of the spaces cut by the surface of the cone.
  • Profile of Thread: The contour of a screw thread ridge and groove delineated by a cutting plane passing through the thread axis, also called form of thread.
  • Root: The bottom surface joining the two sides of the thread.
  • Root Diameter: The diameter of an imaginary cylinder bounding the bottom of the roots of a screw thread (minor diameter of the thread).
  • Thread Series: Groups of diameter/pitch combinations distinguished from each other by the number of threads per unit of measurement. 

View Our Capabilities >

Take a Tour of our Parts Gallery >

 

How Can We Help You?

We’ve got the process, team and capabilities to bring your project within time & budget. Let’s start a conversation.

 

REQUEST A QUOTE