Sheet Metal Hand Tools, Materials, Machines, Safety, and Pattern Development

Comprehensive flashcard deck covering sheet metal hand tools, materials, machines, safety guidelines, and geometric pattern development methods (parallel-line, radial-line, and triangulation).

What gauge range generally defines standard sheet metal working with hand tools and simple machines?

Working metal from $16\,SWG$ down to $30\,SWG$.

At what thickness threshold is a metal piece considered plate rather than sheet or foil?

Pieces thicker than $6\,mm$ ($0.25\,in$) are considered plate, while extremely thin pieces are foil or leaf.

What is the accuracy of a standard steel rule used in sheet metal work?

It measures and lays out small work with an accuracy up to $0.5\,mm$.

What is the accuracy of a folding rule?

It measures and lays out larger workpieces with an accuracy up to $0.5\,mm$.

What is the function and design of a circumference rule?

It is used to find directly the circumference of a cylinder; one edge is marked with diameters and the corresponding circumference values are marked on the other edge.

What is the measuring precision of a vernier caliper?

It measures dimensions up to $0.02\,mm$.

What is the measuring precision of a micrometer caliper?

It measures sheet metal thickness accurately up to $0.01\,mm$.

What is the primary function of a sheet metal gage?

It is used to measure the thickness of the metal sheet.

What is a straight edge and how is it used in layout?

It is a steel bar with one long edge beveled, coming in a variety of lengths, used for drawing long straight lines.

What is a scriber and how is it designed?

It is a steel wire with one sharply pointed and hardened end, used to mark layout lines on sheet metal.

What are dividers used for in sheet metal layout?

Dividers are used to draw circles or arcs on sheet metal and to divide lines into two equal parts.

What is the purpose of trammel points?

They are used to describe large circles and arcs beyond the limits of dividers.

What is the difference in function between a prick punch and a centre punch?

A prick punch is used for making small dots, whereas a centre punch is used for making location points and centers of holes to be drilled.

What is the general application of a ball peen hammer in sheet metal work?

It is a general-purpose hammer used for forming shapes by hollowing, stretching, or throwing off.

What is a rivet hammer used for?

It is specifically used for spreading rivets.

What is the function of a setting hammer?

Its flat face is used for flattening seams without causing damage to the sheet metal.

What is the purpose of a raising hammer?

It is used for denting the metal down to shape.

What materials are mallets constructed from, and when are they applied?

Mallets may be made of fiber, plastic, wood, or rubber, and are used wherever light blows are required.

What maximum material thickness can hand snips or shears cut?

Snips are used only to cut $20\,gage$ or thinner metals.

How do straight snips and bent snips differ in application?

Straight snips are used for straight cuts, while bent snips are used to make curved cuts.

How do flat nose pliers differ from round nose pliers?

Flat nose pliers are used for forming and holding work, while round nose pliers are used for holding and forming into various round shapes.

What are stakes in sheet metal work?

They act as a sheet metal worker's anvil and work-supporting tool used for bending, seaming, and forming using a hammer or mallet.

What is the function of a double seaming stake?

It is used specifically to make double seams.

What operations are performed using a break horn stake?

It is used for riveting, forming round and square surfaces, bending straight edges, and making corners.

What is the function of a hatchet stake?

It is used to make straight and sharp bends.

What is a groover used for?

It is used for grooving and flattening a seam.

How is a rivet set constructed to perform its function?

It has a deep hole in the bottom to draw a rivet through metal and a cup-shaped hole to form the finished head of a rivet.

What is soft solder and how is it applied in joining sheet metal?

It is an alloy of tin and lead, transferred to the joint by means of a soldering iron.

What maximum thickness separates sheet metal from metal plate?

A metal plate of thickness less than $4\,mm$ is considered sheet metal.

What are the two general categories of sheets used in a sheet metal shop?

Solid sheets (made of the same metal throughout, like stainless steel) and Coated sheets (parent metal covered with a thin coating of another metal, like galvanized iron).

What are the key properties and applications of black iron sheets?

It is uncoated mild steel with a bluish black appearance, cheapest sheet metal, corrodes rapidly, and is limited to articles to be painted like tanks, pans, and stove pipes.

What is galvanized iron (GI) and why is it zinc-coated?

It is black iron coated with zinc to resist rusting, improve appearance, and permit soldering with greater ease.

What is terne plate and what is its primary application?

It is iron sheet coated with lead, combining iron's rigidity with lead's durability, most commonly used for roofing.

What is the composition and defining feature of stainless steel sheet metal?

It is an alloy of steel with a minimum of $10\text{--}12\%$ chromium, nickel, and other metals; it is a solid sheet that retains luster and has excellent corrosion resistance.

How are copper and lead sheets specified rather than by gauge?

They are specified by their weight per given area in ounces per square foot (e.g., $16\text{-oz.}$ copper weighs $16\,oz$ per sq. ft.).

What is the compositional difference between brass and bronze?

Brass is an alloy of copper and zinc, while bronze is an alloy of copper and tin.

What are the physical properties and density comparison of aluminum?

It is a grayish-white, non-corrosive, malleable, and light metal that is about $\approx 1/3$ as dense as iron.

What is the composition of the aluminum alloy Duralumin (AA 2024)?

It contains $4.5\%$ copper, $1.5\%$ magnesium, and $0.6\%$ manganese.

What is pewter composed of and used for?

It is an alloy of tin and antimony used to produce paint.

What is white metal (Babbit metal) composed of and used for?

It is an alloy of lead, tin, copper, and antimony used as a bearing metal.

What is tin plate?

It is a thin sheet of iron coated with tin to prevent rusting, presenting a very bright silvery appearance.

What is Monel metal composed of?

It is an alloy of copper and nickel used to produce coins.

What is the primary function of a Burring Machine?

It is used to turn burrs on circular disks such as bottoms and covers, and for preparing edges for double seaming cylindrical pieces.

How does a Turning Machine differ from a Burring Machine?

It differs in the sharpness of the edge, making a rounded edge for wiring operations for cylindrical bodies and double seaming.

What is the function of a Wiring Machine?

It is used to complete the edge around the wire after the seat to receive the wire has been prepared.

What operations are performed by a Crimping Machine?

It performs crimping and bending in one pass, and crimps the small ends of pipes and flanges.

What is the function of a Setting Down Machine?

It is used for setting down seams on containers of various shapes to facilitate double seaming operations.

What is the function of a Grooving Machine?

It is used for grooving longitudinal seams in cylinders, completing grooving and flattening of seams in one operation.

What is a Double Seaming Machine used for?

It is used for double seaming flat bottoms to straight or flared cylindrical pieces.

What is the function of a Beading Machine?

It is used for ornamenting and stiffening sheet metal bodies using interchangeable single, ogee, or special rolls.

What is the purpose of a Pipe Folder?

It is used for folding the edges of longitudinal seams of pipes after they have been formed to shape.

What is a Bar Folder used for?

It is used for rapid production of clips and drive cleats, forming sharp locks on sheet edges for wired edges, flanges of various degrees, and single or double hems.

What are the cutting capabilities and operating speed of a Nibbler?

It operates at $1750\,strokes/min$ to cut contours from several directions in sheet metal up to gage $20$, and aluminum, copper, or brass up to gage $16$.

What is a Foot Squaring Shear used for?

It is used for shearing straight cuts on sheet metal and other materials, equipped with front, back, and side bevel gages.

What are the features and angle adjustment range of a Box and Pan Brake?

It is a bench-mounted brake for small work up to $16\,gage$, equipped with an adjustable stop collar from $0^\circ$ to $350^\circ$ for precise duplication.

What feature on a Cornice Brake regulates angle bending for duplicate work?

It features an adjusting stop used for regulating the angle of a bend when duplicate work is to be produced.

What specific rule applies to using compressed air on clothing in the shop?

Compressed air or other gases must never be used to blow dirt, chips, or dust from clothing or protective equipment while it is being worn.

What is the maximum allowable opening size for treadle guards on foot-controlled presses?

Openings in treadle guards must not be more than twice the width of the foot, except for the long bar extending across the machine.

What is a Development in sheet metal pattern work?

It is a flat representation or pattern that, when folded together, creates a 3D object.

What is a Stretch-out Line?

It is the direction of development (unfolding or unrolling) which must be perpendicular to the line of intersection.

What is a Generatrix?

It is a straight line that, when swept along a straight or curved path, generates a ruled surface.

What defines a Ruled Surface?

It is a surface generated by sweeping a straight line (generatrix) along a path; any position of the generatrix is an element of the surface.

What is a Single-Curved Surface?

It is a developable ruled surface that can be unrolled to coincide with a plane, such as a cylinder or a cone.

What is a Warped Surface?

It is a ruled surface that is not developable because no two adjacent positions of the generatrix lie in a flat plane.

What are five common examples of warped surfaces?

Cylindroid, conoid, helicoid, hyperboloid, and hyperbolic paraboloid.

What is a Double-Curved Surface of Revolution?

It is a surface generated by revolving a curved line about a straight line in the plane of the curve (e.g., sphere, torus, ellipsoid, hyperboloid).

What is a Template in pattern development?

It is a guide or pattern made of light metal, stiff cardboard, or thin sheet plastic.

What are the four primary methods of pattern development?

1. Straight-line (angular) development, 2. Parallel-line (cylindrical) development, 3. Radial-line (conical) development, 4. Triangulation (transition piece) development.

When is Parallel-Line Development used?

It is used for articles having parallel sides such as squares, cylinders, rectangles, elbows, offsets, and T-joints.

What is a Girth Line?

It is a line formed from the measurement around the middle/perimeter of an object, drawn to set out the stretch-out length.

How is the perimeter length calculated for a rectangular prism pattern?

$$\text{Perimeter} = (\text{length} + \text{width}) \times 2$$

How is the circumference calculated for a cylindrical prism pattern?

$$\text{Circumference} = \pi \times \text{diameter}$$

Into how many equal divisions is a circular view standardly divided for parallel and radial line development?

It is divided into $12$ equal divisions.

What defines Radial Line Development?

It is a pattern development method where a series of lines radiate from a central point called the apex.

What defines a Right Cone?

It is a cone that has its apex aligned directly above the center of its base.

What dimension determines the pattern radius when laying out a right cone?

The slant height of the side view (from apex to base) equals the pattern radius.

How is $1/12\text{th}$ of a cone's base circumference calculated mathematically?

$$1/12\text{th circumference} = (\pi \times \text{diameter}) / 12$$

When is a right cone identified as truncated?

When it is cut or intersected at an angle other than $90^\circ$ to its axis.

What formula calculates the Apex Height ($H$) for a cone frustum?

$H = \frac{h \times R}{R - r}$ where $h$ is frustum height, $R$ is base radius, and $r$ is top radius.

What is the Golden Rule of Triangulation?

The true length of a line is obtained by placing the top view length of a line at right angles to its vertical height.