Benchwork and Layout Operations 210

This class describes common benchwork operations performed on the mill before and after machining a part and describes common layout tools and procedures.

Class Details

Class Name:
Benchwork and Layout Operations 210
This class describes common benchwork operations performed on the mill before and after machining a part and describes common layout tools and procedures.
Number of Lessons:
Additional Language:
Related 2.0 Class:
Benchwork and Layout Operations 241

Class Outline

  • Objectives
  • The Importance of Benchwork and Layout on the Mill
  • Common Benchwork Operations
  • What Is Layout?
  • Common Layout Tools
  • Sample Part: Layout
  • Hand Tapping
  • Basic Hand Taps
  • Hand Tapping Tools
  • Hand Reaming
  • Types of Hand Reamers
  • Hand Filing
  • Sample Part: Hand Tapping Operation
  • Sample Part: Hand Tapping
  • Summary


  • Describe the purpose of layout and benchwork operations.
  • List common benchwork operations.
  • Describe the advantages of layout.
  • Match the type of layout tools with their descriptions.
  • Describe the layout procedure for the sample part.
  • Describe hand tapping.
  • Explain the purpose of the sequence of hand taps.
  • Identify common types of hand tapping tools.
  • Describe the steps necessary to prepare the sample workpiece for a hand tapping operation.
  • Describe how to hand tap a hole.
  • Describe hand reaming.
  • Match the types of hand reamers with their descriptions.
  • Describe hand filing operations.


  • MSSC Manufacturing Processes and Production


Vocabulary Term Definition
adjustable hand reamer A type of hand reamer that can be adjusted to any size within the range of the reamer. Adjustable reamers are often used for oddly sized holes.
ball peen hammer A type of hammer with a round end and a flat end used to tap the prick punch into the workpiece.
benchwork operation Any operation performed before or after cutting a part. Blueprint reading and hand tapping are benchwork operations.
blind hole A hole that does not pass through a component and has only one opening.
bottoming tap A type of hand tap that has 1 to 1 1/2 tapered threads and is used to tap to the very bottom of the hole. The bottoming tap is the last tap used in the sequence for blind holes.
bushing A hardened steel tube used to guide cutting tools such as drills and reamers.
caliper rule A type of layout tool used to roughly measure inner and outer dimensions. A caliper rule is not as accurate as precision calipers.
chamfer A beveled surface that eliminates a sharp corner, removes burrs, and aids in assembly.
chamfering Machining an angled edge around the end of a workpiece.
combination set A tool that includes a steel rule, center head, square head, and protractor head. The blade of the tool and square head forms a combination square, which is used to lay out angles.
dividers A layout tool used for spacing distances and scribing circles.
edge finder A device used on a machining center to locate the exact position of a part edge along the X-axis or Y-axis.
Electrical Discharge Machining EDM uses a rapid series of electrical sparks to vaporize and remove metal.
engraving A process that cuts thin lines into metal to represent a design or phrase. Companies often require identification numbers to be engraved into parts.
expansion reamer A type of hand reamer that can be expanded with a screw depending on the diameter of the hole.
file card A tool that helps remove chips from a hand file. Chips caught in a file can cause scratches to form on the surface of a workpiece.
filing Using a file with small, sharp teeth to smooth out the surface of metal by abrasion. Filing removes sharpness and can also add a chamfer to the workpiece.
flute A groove cut into the body of a drill, tap, or end mill that aids in chip removal and provides a path for cutting fluids to reach the cutting edges.
graduation line A line on a measuring device that indicates a unit of measurement.
hand reamer A reaming tool with a straight shank and a square tang that can be gripped with a tap wrench.
hand reaming Performing a reaming process manually to enlarge an existing hole by removing a small amount of material.
hand stamping A process that impresses a shape or design into a workpiece.
hand tap The manual tap used in a hand tapping operation.
hand tapping Performing a tapping process manually to cut an internal thread, without using a machine that is externally powered.
helical-fluted reamer A type of hand reamer with spiral flutes often used to ream holes with interruptions.
internal thread A thread that spirals around the interior surface of a hole.
layout The marking of lines, centers, or circles on metal workpieces. Layout work shows size, shape, hole locations, or areas to be machined.
layout dye A fluid that is brushed or sprayed on a metal workpiece before layout. Layout dye allows lines to be seen more clearly.
manual bench tap A device used to ensure the alignment of the tap and the hole in a hand tapping operation.
pipe tap A type of tap used to add an internal thread to a pipe or tube. The tapered portion of the pipe tap helps sealing capabilities.
pitch diameter The measured distance between the pitch points taken in the groove between the threads.
plug tap A type of hand tap that has 3 to 5 tapered threads and is often used second in the sequence of hand taps used to tap blind holes. Plug taps can be used in place of taper taps.
precision steel square A layout tool with two sides that form a 90° angle. Precision steel squares check the squareness of two surfaces to each other.
prick punch A tool used to mark small, sharp points along layout lines to prepare a part for a drilling operation.
protractor head A part of the combination set used to measure angles.
scriber A pen-like tool that creates fine lines on the surface of a workpiece.
steel rule A simple measuring instrument consisting of a long, thin metal strip with a marked scale of unit divisions.
straight-fluted hand reamer A type of hand reamer with straight flutes. Straight-fluted reamers are the most common types of hand reamers.
straight-handle tap wrench A type of tap wrench often used to hold taps with larger diameters. A straight-handle tap wrench gives more leverage and is easier to turn.
tang An extension on the end of a reamer that is used to secure a tap wrench.
tap drill size The size of the drill required for a given threaded hole. The hole is drilled to this size before it is tapped.
tap extractor A tool used to remove broken taps from inside a hole. A tap extractor is held by a tap wrench and grabs the flutes of the tap to remove it.
tap wrench A type of wrench that holds the square end of a tap in order to turn it. Tap wrenches are also used with hand reamers.
taper tap A type of hand tap that has 8 to 10 tapered threads and is often used to tap through holes. A taper tap is the first tap used in a tapping sequence when tapping blind holes.
T-handle tap wrench A type of tap wrench often used to hold taps with smaller diameters. A T-handle tap wrench is turned with the palm of the hand and often requires more pressure.
thread plug gage A cylinder of heavy metal with threaded ends used to check ID threads. A plug gage is also used to calibrate thread ring gages.
through hole A hole that begins on one side of a workpiece and extends through and exits another surface of the workpiece.
tolerance A blueprint specification indicating an unwanted but acceptable deviation from a given dimension.
vise A workholding device with two jaws that grip and hold a workpiece in place.