Single Point Cutting Tool

Single point cutting fits in the category of machining as a manufacturing process. It involves the removal of metal from a workpiece using cutting tools that only have one primary cutting edge. Single point cutting using standard tools and equipment is a good option for the production of small batches and 1 off items such as prototypes. Machines are flexible and can be used for the production of a large range of components without the need for dedicated tooling. Basic set up costs are relatively low.

Characteristics of Single Point Cutting Tools

• Hardness even at high temperatures
• Toughness
• Chemical
• Resistant to wear

These characteristics have traditionally been found through the adoption of carbon and low alloy steels, although they did have a tendency to wear a little too easily. Being relatively easy to sharpen offset this problem to an extent but there was a clear need for further development  of tooling which could perform better.
High speed steels provided an initial solution to the wear problem, which was mainly brought about as a result of high temperatures being present while machining that would have an adverse affect on the low alloy steels. The high speed steels are still considered to be an affordable and effective choice for cutting most materials, but more recently there has been an adoption of cemented carbide inserts.
Cemented carbide tips are used in conjunction with tool holders and are normally supplied in a triangular geometry which can now be rotated in the holder to provide a new cutting tip when it does wear simply by loosening a retaining screw and clamp. Early designs used brazing to secure the carbide tip in its holder which, for obvious reasons, made continued use of the tip after wear impractical.
Further improvements in wear resistance came in the form of ceramic coatings that could be used on both high speed steels and cemented carbide tools. Diamond is another cutting tool material but is pretty much limited to low temperature applications, despite it being the hardest known material available.

Nomenclature of Single Point Cutting Tool

The single point cutting tool has only one cutting point or edge. These tools used for turning, boring, shaping or planning operations. These tools used on lathe, boring and shaper machines.

A single point cutting tool consists of a sharpened cutting part and the shank and main parts or elements which are:
1: Shank
It is the main body of the tool.
2: Flank:
The surface or surfaces below the adjacent to the cutting edge is called flank of the tool.
3: Face
The surface on which the chip slides is called the face of the tool.
4: Heel
It is the intersection of the flank and the base of the tool.
5: Nose
It is the point where the side cutting edge and end cutting edge intersect.
6: Cutting Edge
It is the edge on the face of the tool which removes the material from the work piece. The cutting edge consists of the side cutting edge(major cutting edge) and cutting edge(minor cutting edge) and the nose.

Single Point Cutting Tool Angles

The single point cutting tool mainly focus at their angles. The angle in cutting tool is following

• Side rake angle :This angle has major effect on the power efficiency as well as on the tool life. The value of this angle lies between 15° to 25°.
• Back rake angle : This angle controls the flow of chips, thrust force of the cut and the power of cutting tool edge. The value of this angle lies between 4° to 8°.
• Side cutting edge angle :This angle can reduce the thickness of chips. The value of this angle lies between 10° to 15° and is also called as lead angle.
• True rake angle :This angle has prime importance in metal removal process. All three angles which are discussed above are directly affected by this angle. If we have high positive true rake angle then less force, power and heat generate. The value of true rake angle can either be positive or negative but it totally depends upon the cutting tool material, machine rigidity and some other variables.
• End cutting edge angle :This angle provides us some clearance between cutter and finished surface of the work piece. If the value of angle is very close to zero then the tool strength will increase and if we take a larger value then it weakens the tool. The value of this angle lies between 8° to 15°.
• Nose radius:This angle gives us the strength to cutting edge, improves finish and also put some stress on the life factor of the tool. If we take a large value then it produces large radial force .But if we take too small value then it stops proper distribution of heat and reduces cutting tool material properties.
• Primary clearance angle :This angle is below cutting edge angle and is used to prevent tool from rubbing.
• Secondary clearance angle :This angle is on the tooth forms of shank and has a large value so it can permit chips to escape easily. But if we take too large value then it weakens the tool, so to avoid this problem we take economical value.

Tool Engineering Elements and work Area

Tool engineering is a division of industrial engineering whose function is to plan the processes of manufacture, develop the tools and machines, and integrate the facilities required for producing particular products with minimal expenditure of time, labours, and materials.
Tool engineers can find job opportunities in Product Drafters, Entry - Level Tool Designers, CAD Operators and Other Technical - related positions. Well trained and qualified tool engineers occupy important positions of responsibility with good scope for career enhancement in manufacturing industries. Tool Engineering Graduates an opportunity to acquire advanced skills and knowledge relating to Tool Design and Manufacturing with extensive exposure to CAD / CAM / CAE and GD&T to meet the growing demands of the industries

Tool Engineering Elements:

The basic elements of tool engineering are single point cutting tool and multiple point
cutting tool.

• Single Point Cutting Tool

The cutting tool, which has only one cutting edge, is termed as single point cutting tool.
Single point cutting tools are generally used while performing turning, boring, shaping
and planing operation. The important elements in single point cutting tools are rake
angle, principle cutting edge, nose etc.

• Multi Point Cutting Tool

A cutting tool which has more than one cutting edge is multipoint cutting tool. Multi
point cutting tools are generally used while performing drilling, milling, broaching,
grinding etc. Important elements are cutting edge, helix angle, the number of teeth. The
cutting edge is the only element that comes in direct contact with the work. The axial 8
Fundamentals of CIM angle corresponds to side rake angle in single point tool and similar angle with respect to the cutting axis, i.e. the radial angle is same as the back rake angle.

Work Areas:

Some of the common job profiles for tool makers are as follows:

• Tool and die makers
• Mold maker
• Tool fitter
• Jig maker
• Designers

Tool and Die Maker Apprentice Training

From metal processing and grinding to forging and manufacturing, the Tool and Die Maker Apprentice Training curriculum offers a complete introduction for the professional tool and die maker.

Beginning with a systematic review of pre-technical skills in safety, drawings, and measurements, the curriculum takes students, step by step, through the fundamentals of tool grinding, metallurgy, and the manufacturing process.

Like many Penn Foster apprentice programs, this Machinist/Machinist Apprentice has been developed to meet Bureau of Apprenticeship and Training (BAT) standards. Be sure to offer your employees on-the-job training opportunities to supplement the skills learned here. Upon completion of this program, students will be able to:

Read working drawings.

Identify different types of cutting tools.

Explain the function of forming dies.

Select the proper machine tool for a job.

Explain how to recognize steel alloys.

Explain the use of a fixture.

Explain the function of forging dies.

Describe a layout procedure.

Discuss the hardening and tempering of steels.

Explain the various uses of a jig.

Discuss the use of drill bushings.

Explain how to lay out a casting.

Describe various press operations.

Career Advice on How to Become a Tool and Die Maker

Tool and die makers are among the most skilled of all tradesmen. The typical tool and die maker builds other tools that are then used in the manufacturing process. The tools which a tool and die maker creates are used to form metal into different shapes, whether this is done through cutting or bending. 

A die is a metal form that is used to shape metal, but tool and die makers also make molds as well. These molds can be used to produce parts made of almost any material, ranging from plastic to even composite materials. Due to the nature of the work, tool and die makers frequently work with engineers and need to have a detailed knowledge of machine operation, as well as an ability to read blueprints.

Career Facts:

Those engaged in career planning realize that tool and die makers often have several years of classroom training, usually at least four years. This training is in addition to their apprenticeships and additional course work often at technical schools. Tool and die makers with a college degree can also venture into engineering or tool design. The numbers for this skilled position are expected to decline.

Career Opportunities and Job Outlook-Fair:

While this occupation may be very skilled, there is an expected decrease in their numbers. In 2006, there were 101,000 tool and die makers. As of 2016, that number is expected to contract considerably to 91,000. This is a significant ten-percent reduction.  

On the plus side, however, because of the vital nature of their work for industry at large, the tool and die maker is more protected from layoffs than many other workers involved in manufacturing. However, the overall picture is complicated, as there are not enough projected skilled tool and die workers to meet the demand. The job search for those looking for a career in tool and die should be a fruitful one.

A Day in The Life:

Tool and die makers are highly skilled, and, as a result, are often able to bypass some of the more dangerous jobs in manufacturing. Traditionally, their skill sets are sought after by the manufacturing industry. Increasingly, they are using computers in their work. Tool and die makers need to know how to work with engineers and read blueprints. This is vital to their job, for without the ability to read blueprints, tool and die makers can simply not build the machines necessary.

Tool and die makers spend most of their day literally building machines or tools and dies from the ground up. The end result is a serious contribution to the manufacturing process.

Average Salary:

Despite the very high level of skill that the job requires, tool and die makers do not enjoy a pay that is reflective of their overall skill. On average a tool and die maker earns about $21 per hour, with the top ten-percent of earners seeing about $32 per hour.

$40k - $67k

Career Training and Qualifications:

Several years of technical training and apprenticeship is quite common for this career’s training. Additional training at technical schools and community colleges is likewise common. Due to the skill level involved, constant on the job training is also the norm.

Cold Saw

Portable saws

These saws were primarily designed for sheet metal roofers in the building industry. Cold saws, as opposed to abrasive saws, are used so that protective coating is not damaged. They also have a heavy duty aluminium catcher which is useful for capturing the swarf.

They can cut up to 6mm (0.24in) thick mild steel. They use cermet tipped blades.

Blades

Cold saw blades are circular metal cutting saw blades categorized into two types: solid HSS or tungsten carbide-tipped (TCT). Both types of blades are resharpenable and may be used many times before being discarded. Cold saw blades are used to cut metal using a relatively slow rotational speed, usually less than 5000 surface feet per minute (SFM) (25m/s), and a high chip load per tooth, usually between .001" - .003" (0.025 - 0.08mm) per tooth. These blades are driven by a high power motor and high-torque gear reduction unit or an AC vector drive. During the cutting process, the metal is released in a shearing action by the teeth as the blade turns and the feed mechanism moves the blade forward. They are called "cold saw blades" because they transfer all the energy and heat created during the cutting process to the chip. This enables the blade and the work material to remain cold.

Classification

The first type of cold saw blade, solid HSS, may be made from either M2 tool steel or M35 tool steel, alloyed with additional cobalt. Solid HSS saw blades are heat treated and hardened to 64/65 HRC for ferrous cutting applications and 58/60 HRC for non-ferrous cutting applications. This high hardness gives the cutting edges of the teeth a high resistance to heat and wear. However, this increased hardness also makes the blades brittle and not very resistant to shock. In order to produce a high quality HSS cold saw blade, you must start with very flat and properly tensioned raw material. The blades must be press quenched after hardening to prevent them from being warped. The term HSS doesn't necessarily mean what it implies. These blades are usually never run at surface speeds higher than 350 SFM. Solid HSS cold saw blades may be used for cutting many different shapes and types of metal including: tubes, extrusions, structural sections, billets, bars, ingots, castings, forgings etc. These blades may also be coated with special wear resistant coatings such as titanium nitride (TiN) or titanium aluminum nitride (TiAlN).

The second type of cold saw blade, tungsten carbide-tipped (TCT), are made with an alloy steel body and tungsten carbide inserts brazed to the tips of the teeth. These tips are ground on all surfaces to create tangential and radial clearance and provide the proper cutting and clearance angles on the teeth. The alloy body is generally made from a wear resistant material such as a chrome vanadium steel, heat treated to 38/42 HRC. The tungsten carbide tips are capable of operating at much higher temperatures than solid HSS, therefore, TCT saw blades are usually run at much higher surface speeds. This allows carbide-tipped blades to cut at faster rates and still maintain an acceptable chip load per tooth. These blades are commonly used for cutting non-ferrous alloys, but have gained significant popularity for ferrous metal cutting applications in the last 10 years. The tungsten carbide inserts are extremely hard (98 HRC) and capable of very long wear life. However, they are less resistant to shock than solid HSS cold saw blades. Any vibration during the cutting process may severely damage the teeth. These cold saw blades need to be driven by a backlash free gear box and a constant feed mechanism like a ball-screw feed.

Future

The popularity of cold saw blades is increasing due to the technological advancements in cold saw machines. They are the sawing method of choice when high production requirements are needed. They consistently produce the lowest cost per cut among all sawing methods: hot sawing, friction sawing, bandsawing and hacksawing.

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Metalworking

Tools

Cutting machines

Water jet cutter Band saw Cold saw Laser Miter saw Plasma

Cutting tools

Broach Burr Chisel Counterbore Countersink End mill File Guillotine shear Hand scraper Milling cutter Nibbler Reamer Throatless shear Tipped tool Tool bit

Forming tools

Brake Die English Wheel Flypress Hydraulic press Machine press Punch press Stamping press

Hand tools

Clamp Combination square Drift pin File card Hacksaw Hammer Hand scraper Machinist square Magnetic base Needlegun scaler Pipe and tube bender Pliers Punch Saw piercing Scriber Tap and die Tongs Vise Workbench Wrench

Machine tooling

Angle plate Chuck Collet Jig Fixture Indexing head Lathe center Machine taper Magnetic base Mandrel Rotary table Wiggler

Measuring instruments

Bore gauge Caliper Comparator Dial indicator Engineer's blue Feeler Center gauge and fishtail gauge Gauge block Gauge Go-NoGo Machinist square Marking blue Marking gauge Marking out Micrometer Radius gauge Scale Sine bar Spirit level Straightedge Surface plate Tape measure Thread pitch Height gauge Vernier scale Wiggler

Smithing tools

Anvil Forge Fuller Hardy hole Hardy tools Pritchel Slack tub Steam hammer Swage block Trip hammer

Casting Fabrication Forming Jewellery Machining Metallurgy Smithing Tools & Terminology Welding.

Tool

A tool is any physical item that can be used to achieve a goal, especially if the item is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tool use by humans dates back millions of years, and other animals are also known to employ simple tools.

Tools that are used in particular fields or activities may have different designations such as "instrument", "utensil", "implement", "machine", or "apparatus". The set of tools needed to achieve a goal is "equipment". The knowledge of constructing, obtaining and using tools is technology.

History

Prehistoric stone tools over 10,000 years old, found in Les Combarelles cave, France

Carpentry tools recovered from the wreck of a 16th century sailing ship, the Mary Rose. From the top, a mallet, brace, plane, handle of a T-auger, handle of a gimlet, handle of a hammer?, rule.

Stone and metal knives

An upholstery regulator

Anthropologists believe that the use of tools was an important step in the evolution of mankind. Humans evolved an opposable thumb — useful in holding tools — and increased dramatically in intelligence, which aided in the use of tools. Because tools are used extensively by both humans and wild chimpanzees, it is widely assumed that the first routine use of tools took place prior to the divergence between the two species. These early tools, however, were likely made of perishable materials such as sticks, or consisted of unmodified stones that cannot be distinguished from other stones as tools. The beginning of the Stone Age marks the era when hominins first began manufacturing stone tools, and evidence of these tools dates back at least 2.6 million years in Ethiopia. One of the earliest distinguishable stone tool forms is the hand axe.

Up until recently, weapons found in digs were the only tools of “early man” that were studied and given importance. Now, more tools are recognized as culturally and historically relevant. As well as hunting, other activities required tools such as preparing food, “…nutting, leather working, grain harvesting and woodworking…” Included in this group are “flake stone tools (which may or may not have been used more commonly by women).” This recognition in other tools used by early people is attributed to the addition of feminist perspective in anthropology and archaeology.

Tools are the most important items that the ancient humans used to climb to the top of the food chain; by inventing tools, they were able to accomplish tasks that human bodies could not, such as using a spear or bow and arrow to kill prey, since their teeth were not sharp enough to pierce many animals' skins. “Man the hunter” as the catalyst for Hominin change has been questioned. Based on marks on the bones at archaeological sites, it is now more evident that pre-humans were scavenging off of other predator’s carcasses rather than killing their own food.

The transition from stone to metal tools roughly coincided with the development of agriculture. Mechanical devices experienced a major expansion in their use in Ancient Greece and Ancient Rome with the systematic employment of new energy sources.especially waterwheels. Their use expanded through the Dark Ages with the addition of windmills.

Machine tools occasioned a surge in producing new tools in the industrial revolution. Advocates of nanotechnology expect a similar surge as tools become microscopic in size.

Functions

One can classify tools according to their basic functions:

• Cutting tools, such as the knife, scythe or sickle, are wedge-shaped implements that produce a shearing force along a narrow face. Ideally, the edge of the tool needs to be harder than the material being cut or else the blade will become dulled with repeated use. But even resilient tools will require periodic sharpening, which is the process of removing deformation wear from the edge. Other examples of cutting tools include gouges and drill bits.
• Moving tools move large and tiny items. Most are levers which give the user a mechanical advantage. For example, concentrating-force tools: the hammer moves a nail, the maul moves a stake, or a whip moves flesh on a horse. These operate by applying physical compression to a surface. In the case of the screwdriver, the force is rotational and called torque. Writing implements deliver a fluid to a surface via compression to activate the ink cartridge. Also grabbing and twisting nuts and bolts with pliers, a glove, a wrench, etc. All these tools move items by some kind of force. Also trucks, rockets and airplanes move larger items and particle accelerators move very small items.
• Tools that enact chemical changes, including temperature and ignition, such as lighters and blowtorches.
• Guiding, measuring and perception tools include the ruler, glasses, set square, sensors, straightedge, theodolite, microscope, monitor, clock,phone, printer
• Shaping tools, such as molds, jigs, trowels.
• Fastening tools, such as welders, rivet guns, nail guns, or glue guns.
• Information and data manipulation tools, such as computers, middleware, IDE, spreadsheets

Some tools may be combinations of other tools. An alarm-clock is for example a combination of a measuring tool (the clock) and a perception tool (the alarm). This enables the alarm-clock to be a tool that falls outside of all the categories mentioned above.

There is some debate on whether to consider protective gear items as tools, because they do not directly help perform work, just protect the worker like ordinary clothing. They do meet the general definition of tools and in many cases are necessary for the completion of the work. Personal protective equipment includes such items as gloves, safety glasses, ear defenders and biohazard suits.

Tool substitution

Often, by design or coincidence, a tool may share key functional attributes with one or more other tools. In this case, some tools can substitute for other tools, either as a makeshift solution or as a matter of practical efficiency. "One tool does it all" is a motto of some importance for workers who cannot practically carry every specialized tool to the location of every work task; such as a carpenter who does not necessarily work in a shop all day and needs to do jobs in a customer's house. Tool substitution may be divided broadly into two classes: substitution "by-design", or "multi-purpose" use, and substitution as makeshift. Substitution "by-design" would be tools that are designed specifically to accomplish multiple tasks using only that one tool. Substitution as makeshift is when human ingenuity comes into play and a tool is used for its unintended purpose such as a mechanic using a long screw driver to separate a cars control arm from a ball joint instead of using a tuning fork. In many cases, the designed secondary functions of tools are not widely known. As an example of the former, many wood-cutting hand saws integrate a carpenter's square by incorporating a specially shaped handle that allows 90° and 45° angles to be marked by aligning the appropriate part of the handle with an edge and scribing along the back edge of the saw. The latter is illustrated by the saying "All tools can be used as hammers." Nearly all tools can be used to function as a hammer, even though very few tools are intentionally designed for it and even fewer work as well as the original.

Tools are also often used to substitute for many mechanical apparatuses, especially in older mechanical devices. In many cases a cheap tool could be used to occupy the place of a missing mechanical part. A window roller in a car could easily be replaced with a pair of vise-grips or regular pliers. A transmission shifter or ignition switch would be able to be replaced with a screw-driver. Again, these would be considered tools that are being used for their unintended purposes, substitution as makeshift. Tools such as a Dremel would be considered the substitution "by-design", or "multi-purpose". This class of tools allows the use of one tool that has at least two different capabilities. "Multi-purpose" tools are basically multiple tools in one device/tool. Tools such as this are often power tools that come with many different attachments like a Dremel does, so you could say that a power drill is a "multi-purpose" tool because you can do more than just one thing with a power drill.

Multi-use tools

Bicycle multi-tool

A Multi-tool is a hand tool that incorporates several tools into a single, portable device; the Swiss army knife represents one of the earliest examples. Other tools have a primary purpose but also incorporate other functionality - for example, lineman's pliers incorporate a gripper and cutter, and are often used as a hammer; and some hand saws incorporate a carpenter's square in the right-angle between the blade's dull edge and the saw's handle. This would also be the category in which the "multi-purpose" tools since they are also multiple tools in one (multi-use and multi-purpose can be used interchangeably). These types of tools were specifically made to catch the eye of many different craftsman who traveled to do their work. To these workers these types of tools were revolutionary because they were one tool or one device that could do several different things. With this new revolution of tools the traveling craftsman would not have to carry so many tools with them to job sites, being that their space would be limited to the vehicle they were driving. The problem of having to deal with so many different tools was solved with the overtaking of multi-use tools.

Use by animals

A Bonobo at the San Diego Zoo "fishing" fortermites

Observation has confirmed that a number of species can use tools including monkeys, apes, elephants, several birds, and sea otters. Philosophers originally thought that only humans had the ability to make tools, until zoologists observed birds and monkeys making tools. Now the unique relationship of humans with tools is considered to be that we are the only species that uses tools to make other tools.

Tool metaphors                                          telephone is a communication tool that interfaces between two people engaged in conversation at one level. It also interfaces between each user and the communication network at another level. It is in the domain of media and communications technology that a counter-intuitive aspect of our relationships with our tools first began to gain popular recognition. Marshall McLuhan famously said "We shape our tools. And then our tools shape us." McLuhan was referring to the fact that our social practices co-evolve with our use of new tools and the refinements we make to existing tools.

In North American colloquialism, the word "tool" may be loosely used to describe an individual of low mental capacity (essentially, an "idiot") or someone who fails to realise that they are being taken advantage of by others.This metaphor is drawn from the understanding that tools (as understood by most of society) are objects that are used for specific tasks.

Eliminating slug pulling during piercing operations

Slug pulling is the tendency for a pierced-out slug to stick to the face of the pierce punch during withdrawal. If the slug pulls out of the matrix (button) and falls off the punch face, it may cause double metal to be introduced into the die, resulting in die shearing, broken punches, broken die steel, surface defects, and numerous other problems.

It's truly amazing (or amusing) just how many dies are designed and built with very little attention given to the problem of slug pulling. In an effort to reduce die cost, stampers often procure the cheapest possible punches and buttons, including punches without slug ejectors.

Slug pulling often can be a big problem with progressive dies, but it also can be a problem with larger single-station or transfer dies.

Slug pulling is caused by several factors:

• A small vacuum pocket is created during piercing between the face of the pierce punch and slug.
• Lubricants cause a "gluing" effect.
• Cutting clearance is excessive.
• Suction is created between the punch and matrix during punch withdrawal.

Figure 1 Pierce punches equipped with slug ejector spring pins are commercially available from most pierce punch providers.	Figure 2 The urethane must be ground flat on three sides to allow for expansion on sheet metal contact and then press-fit into the punch end.

How the stamper uses two basic items involved in piercing—the punch and the matrix—can help decrease or eliminate slug pulling. Of course, these solutions will not work for every application.

The Pierce Punch

Spring-loaded Slug Ejector Pins. Pierce punches equipped with slug ejector spring pins are commercially available from most pierce punch providers (see Figure 1). Most punches have some type of provision for locking the pin in its full depressed position. This allows for the punch to be sharpened while maintaining the same spring travel.

The small hole in the side of the punch allows for a spring retention pin to be inserted. It also should allow trapped air to travel around the pin and out the hole. Often the spring pin fits like a piston in the hole and does not allow for trapped suction to be relieved. An ideal spring ejector has a somewhat sloppy pin.

These types of ejectors work well in slower single-station operation but often fail in high-speed progressive dies.

Punches purchased without slug ejector pins can be jury-rigged later if time and financial resources are limited. This quick fix consists of a small piece of urethane inserted into the end of a punch that has had a hole burned or carbide drilled into its tip. The urethane must be ground flat on three sides to allow for expansion on sheet metal contact and then press-fit into the punch end (see Figure 2).

Figure 3 During piercing, the slug that's created has a natural curvature. It causes a vacuum pocket, which makes the slug stick to the face of the punch, resulting in slug pulling.	Figure 4 Rooftop shear, cone-shaped punch tip, and balled punch face all force the slug to deform into a longer length of line before most of the cutting takes place.

Slotted Punch Face. During piercing, the slug that's created has a natural curvature. It causes a vacuum pocket, which makes the slug stick to the face of the punch, resulting in slug pulling (see Figure 3). Slotting or grinding grooves in the punch face helps relieve the suction created between the face of the punch and the slug.

Rooftop Shear, Cone-shaped Punch Tip, and Balled Punch Face. All three of these methods force the slug to deform into a longer length of line before most of the cutting takes place. This allows the slug to expand in the matrix and resist pulling up with the punch (see Figure 4).

Air Blown Through the Punch. A timed blast of air through the pierce punch can remove the slug from the punch face. However, a continuous flow of air through the punch could cause vital lubricant to be blown away during the piercing process.

The Matrix

Slug-retention Matrix. A slug-retention button (see Figure 5) consists of two small slots machined at an angle in each side of the matrix. These slots cause a burr to be generated on the slug. The burr is forced downward at an angle, wedging the slug in the matrix.

With a slug-hugger button (see Figure 6), barbs in the matrix impale themselves into the slug. An industrial quick-fix alternative to the slug hugger is to place tiny weld spatter on the inside of the pierce hole.

Reverse-tapered Matrix. This method may look a little strange at first, but if the matrix is properly manufactured, it works pretty well.

Figure 5 A slug-retention button consists of two small slots machined at an angle in each side of the matrix. These slots cause a small burr to be generated on the slug.	Figure 6 With a slug-hugger button, barbs in the matrix impale themselves into the slug.	Figure 7 A reverse-tapered button allows for the slug to be held in compression in the matrix.

Most die buttons have a bell mouth taper machined into them, with the hole diameter increasing toward the bottom of the button. A reverse-tapered button gets smaller in diameter to a certain point and then increases in diameter. This reverse taper allows for the slug to be held in compression in the matrix (see Figure 7).

Vacuum Slug Removal. Vacuum units are available to pull slugs from the punch face. While these work well, they can be expensive.

Slug pulling is a serious and costly problem in cutting and piercing operations and should not be taken lightly. There are many more methods to prevent it than those discussed here, and spending a little extra time and a little money addressing this problem will save stampers even more in the end.