NIMS Core Drill Press Skills 241

adjustable hand reamer

A type of hand reamer that expands and contracts slightly to sizes within a small range. Adjustable reamers are often used for oddly sized holes.

assembly

The process of joining objects. Assembly can include use of fasteners, adhesives, or welding.

ball peen hammer

A type of hammer with a round end and a flat end used to tap the center punch into the workpiece. Ball peen hammers are also known as machinists' hammers.

base

The foundation of a machine that supports all the other machine components. Bases provide both stability and rigidity.

benchwork operations

Any additional process performed on a workpiece before or after it is machined. Benchwork operations are generally manual, such as hand tapping and hand reaming.

bill of materials

BOM. A report that lists the materials required to make a particular product and the cost of each individual component. A bill of materials includes all project materials, including any accessories and fasteners.

blind hole

A hole that begins on one side of a workpiece and ends inside the workpiece. Blind holes do not extend through the entire thickness of a workpiece, so they only have one opening.

blocks

A rectangular piece of metal used to reinforce a machining operation. Blocks provide a large locating and support area but must be precisely machined.

blueprint

A document containing all the instructions necessary to manufacture a part. A blueprint includes a part drawing, dimensions, and notes.

bonded abrasive wheel

A grinding tool made of grits that are held together with chemical bonding into a circular shape. A bonded abrasive wheel rotates along the surface of a part to remove material.

bottoming tap

A type of hand tap that has 1 to 1 1/2 tapered threads. Bottoming taps are the last tap used when hand tapping blind holes.

bushing

A hardened steel tube that guides drills, reamers, and other cutting tools. Bushings ensure a cutting tool enters a drilled hole at the correct angle.

buttons

A fixture component with a flat, circular head. Buttons fit in the holes on fixtures and provide both external locating and support.

carbon tool steel

A type of steel designed with improved wear resistance, toughness, and strength. Hand reamers are commonly made of carbon tool steel.

center drill

A type of drill with a wide shank and a 60° angle tip. The center drill is used to start a hole and can be used to align the cutting tool to a center punch mark to ensure that the hole is machined in the right location.

center punch

A tool used to mark small, sharp points along layout lines. Center punches create small indentations that indicate the centers of holes when preparing for drilling operations.

chamfer

An angled surface that eliminates a sharp corner, removes burrs, and/or aids in assembly. Chamfers generally replace a 90° angled surface with a 45° angled surface.

chamfer tool

A tool that creates an angled surface which eliminates a sharp corner on a workpiece. Chamfer tools are available in a range of angles.

clamped

Securely held against locators. Clamping a workpiece helps it resist the cutting forces that occur during machining.

clamps

A workholding device component that tightens to hold a workpiece in place when it is exposed to the manufacturing forces of cutting. Clamps include strap clamps, screw clamps, and toggle clamps.

coatings

A finish used for protective and decorative purposes. Coatings like paint or varnish are applied to products at the end of the part creation process.

column

The rigid, vertical support section of the machine. Columns suspend components and tools over the workpiece and also support components.

countersinking

The cutting of a beveled edge at the end of a hole. Countersinking allows the head of a screw to rest level with the workpiece surface.

cutting fluid

A type of coolant used to cool or lubricate a metal cutting process. Cutting fluids are typically oil- or water-based liquids.

datum

A point of reference for machine tools, programs, and fixtures from which measurements are taken or positions are located. A datum can be a hole, a line, or any three-dimensional shape.

depth factor

A set of pre-calculated values used to determine the proper depth for common countersink angles. The depth factor for the angle multiplied by the fastener head diameter determines the depth.

drill bit

A multi-point cutting tool used to machine round holes into workpieces. Drill bits have spiral cutting edges and are usually mounted in drill presses.

drill press

A machining tool that uses a drill to penetrate the surface of a workpiece and make a round hole. Drill presses can be used for a variety of holemaking operations.

edge finder

A rod shaped tool used to find the exact edge of a part. Edge finders are commonly used in drilling to find the exact location of a hole.

electrical discharge machining

EDM. A nontraditional machining process that erodes unwanted material from a workpiece using a rapid series of electrical sparks. Electrical discharge machining can be used to remove a tap that has broken inside a hole.

expansion reamer

A type of hand reamer that expands slightly with a screw. Expansion reamers only expand and do not contract; the diameter expansion is permanent.

fasteners

A device that holds objects together or locates them in relation to one another. Common fasteners include screws, bolts, and rivets.

feed handle

A handle attached to a machine that controls the movement of the cutting tool . On an upright drill press, the feed handle is located on the head.

feeds

The rate at which the cutting tool and the workpiece move in relation to one another. Feed is typically a linear movement.

finishing

A cutting pass that emphasizes tight tolerances and smooth surface finish. Finishing is usually the last step in the machining process.

fixture

A customizable, modular workholding device created by configuring locators, supports, and clamps on a base plate or worktable. Fixtures are useful when holding irregularly shaped workpieces or when holding multiple workpieces for a single operation.

flutes

A helical recess that winds up the length of the body of a drill, end mill, and tap. Flutes allow for the removal of chips and the entrance of cutting fluids.

grinding

The use of an abrasive tool to remove material from a workpiece. Grinding operations commonly use abrasive grains bonded into a wheel shape.

hand reamer

A manual cutting tool that smooths or enlarges existing holes. Hand reamers have a straight shank and a square tang, or peg, that can be gripped with a tap wrench.

hand reaming

A type of benchwork operation that involves manually removing small amounts of workpiece material to enlarge an existing hole. Hand reaming is performed on holes that require tight tolerances.

hand tap

A manual cutting tool that cuts internal threads into a drilled hole. Hand taps are typically held and driven into a hole by a tap wrench.

hand tapping

A type of benchwork operation that involves manually cutting an internal thread. Hand tapping is performed without the use of a machine tool.

head

The part of a drill press that contains the spindle and the motor. The head of an upright drill press is located at the top of the column and extends over the worktable.

heat treatment

Controlled heating and cooling processes used to change the structure of a material and alter its physical and mechanical properties. Heat treating is often used to adjust a material's hardness.

helical-fluted hand reamer

A type of hand reamer with spiral-shaped flutes. Helical-fluted hand reamers are often used to ream holes with keyways or interruptions.

high-speed steel

HSS. A common cutting tool material that is relatively inexpensive and offers excellent toughness. High-speed steel tools are often heat treated and coated.

insert

A replaceable cutting tool with a geometric shape that has multiple cutting surfaces and is mechanically held in a toolholder. Inserts must sit flat in the insert pockets of a toolholder when properly installed.

insert pockets

An interior recess on a milling holder into which cutting inserts are affixed. Insert pockets must be free of chips and scratches that could cause the insert to sit uneven in the pocket.

keyways

A rectangular slot or groove that is machined down the length of a hole. Keyways make up the specific design of a keyhole.

knurling

A machining operation that displaces material rather than cutting it. Knurling embeds a textured, rough pattern into a part's surface.

layout

A type of benchwork operation that involves manually marking a workpiece with lines, centers, or circles prior to a machining process. Layout shows the size, shape, and location of features to be machined.

layout dye

A colored fluid that a machinist brushes or sprays on a workpiece at the beginning of layout. Layout dye allows surface marks to be seen more clearly.

located

Established in a set position. A correctly located workpiece ensures it will be machined or otherwise manufactured to the correct specifications and tolerance.

locators

A fixture component that positions the workpiece and restricts its movement. Locators must be used in combination with clamping in workholding.

machining

The process of removing material to form an object. Machining methods include milling, turning, and drilling.

major diameter

The distance from crest to crest of an external thread or from root to root of an internal thread. Major diameter is also called thread diameter.

manual bench tap

A device that aligns a hand tap with a hole for a hand tapping operation. Manual bench taps ensure the tap enters the hole straight.

manufacturer’s technical data references

Documents provided by a manufacturer that provide specific information about the products they manufacture. Machinists use manufacturer’s technical data references to help them select the proper cutting tool for a given operation.

minor diameter

The distance from root to root of an external thread or from crest to crest of an internal thread. Minor diameter of a tap measures the farthest distance from root to root on opposite sides of the tool.

mounting stops

A solid component that prevents the movement of another object. Mounting stops on fixtures are the locators and supports.

pins

A cylindrical device, sometimes with a shaped head, used on fixtures to restrict workpiece motion. Pins are the most commonly used fixture locating component.

pitch diameter

The distance that separates points located in the grooves between threads. Pitch diameter is the theoretical point where a fastener's threads meet a hole's threads.

plug tap

A type of hand tap that has 3 to 5 tapered threads. Plug taps are often used after taper taps but before bottoming taps when hand tapping blind holes.

positive stops

A solid component that prevents the movement of another object. Positive stops on fixtures are the locators and supports.

repeatably

Positioning a workpiece in the same place, part after part, for a part run. The ability to repeatably machine is crucial for the efficient, quality production of identical parts.

revolutions per minute

rpm. The number of revolutions that a spindle or cutting tool completes in one minute. Revolutions per minute is a measurement of speed in both English and metric systems.

roughing

A cutting pass that removes material without regard to surface finish. Roughing is often used to separate part pieces from a single sheet of material.

runs true

Having a common center or sharing the same axis with another object. If a cutting tool runs true, it shares a centerline with the drill press spindle.

sanding

A form of grinding that uses a fine grain abrasive to remove small amounts of surface material. Sanding improves the finish of a surface.

scriber

A pen-like layout tool. Scribers create fine lines on the surface of a workpiece.

setscrew

A type of screw with a rounded or cone-shaped end designed to fit into a matching recess. A setscrew is used to expand an expansion reamer.

shank

A long cylindrical part of a tool or device, such as a drill or a reamer. The shank of a reamer has flutes.

speeds

The rate at which the workpiece passes the cutting tool at the point of contact. Surface speed has the greatest effect on tool life.

spindle speed

The rate at which the machine spindle rotates. Spindle speed is typically measured in revolutions per minute.

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 with a long, straight handle that usually holds large-diameter taps. Straight-handle tap wrenches are easier to turn because they provide a machinist with more leverage than other tap wrenches.

surface finish

The degree of roughness and variation on the surface of a part after it has been manufactured. The surface finish of a part may need to be smooth or intentionally rough.

tang

A square extension on the end of a reamer. Tangs allow reamers to be secured in tap wrenches.

tap extractor

A tool that grabs the flutes of a broken tap to remove it from inside a hole. Tap extractors are held and turned by a tap wrench.

tap wrench

A manual tool that holds a hand tap's square end and allows a machinist to turn the hand tap. Tap wrenches can also be used with hand reamers.

taper tap

A type of hand tap that has 8 to 10 tapered threads. Taper taps are the first tap used when hand tapping blind holes, and they are also often used to tap through holes.

tapered

Gradually decreasing in size from one end of the object to the other. Tapered taps create a conical shape at the bottom of a hole to fit screws.

T-handle tap wrench

A type of tap wrench that is shaped like a 'T' and often used to hold smaller-diameter taps. T-handle tap wrenches require more force to manually rotate than other tap wrenches.

thread gage

A measuring instrument used to inspect the threads of a part. Thread gages are made for either internal or external thread inspection.

threads

A long, spiraling groove that may appear on a workpiece or tool surface. Threads help fasteners, such as screws, grip material and hold components together.

through hole

A hole that passes through the entire thickness of a workpiece. Through holes have no bottom because they pass through both sides of a workpiece.

tool crib attendant

A worker whose job involves the inventory of cutting tools. Tool crib attendants inspect tools for damage, store them for later use, and distribute them as needed.

upright drill press

A type of drill press on which the head extends over the worktable. On an upright drill press, the column supports both the head and the worktable.

vise

A workholding device with two jaws that grip and hold a workpiece in place. Vises used in benchwork operations have one fixed and one movable jaw.

visual inspection

A visual assessment of surface defects. Visual inspection involves closely examining with the naked eye to check for defects.

workbench

A flat structure, similar to a table, that is used to perform manual cutting operations. Workbenches provide the surface and support for performing benchwork operations.

workholding

A method or device for securing a workpiece for a machining operation. Workholding can include chucks, vises, and bolts.

worktable

The machine component that supports the workpiece and any workholding devices during machining. Worktables may provide the surface and support for performing benchwork operations.