Sheet Metal Hand Tools and Machinery 116- Trade Skills Sheet Metal Hand Tools and Machinery

Tools and Machines are an integral component of sheet metal work. They make it possible to lay out, form, bend, and join metal. Knowing when and how to use each item is an important responsibility of a sheet metal worker.

Hand Tools There are a variety of hand tools that are still important to the sheet metal worker. Hand tools tend to be used in specialized circumstances, to do custom and small run jobs. Important hand tools for sheet metal worker include: Hacksaw Files Chisels Hammers Mallets Screwdrivers Pliers Wrenches Hand punches

Hacksaw A hacksaw is used to saw metal. Hacksaws have either: A fixed frame An adjustable frame Adjustable frame hacksaws have several different blade lengths.

The can come in lengths of: 8”, 10” and 12” blades The number of teeth on the blades can also varies. They can range from 14 to 32 teeth per inch.

Files Files are categorized according to their: Shape Size Teeth Coarseness They come in two basic shapes. Blunt Tapered

There are two basic filing methods: Some considerations need to be made when selecting the proper file for the job: Type of metal being filed. Surface finish needed. Shape, location, and size of the part to be filed. Amount of material to be removed. There are two basic filing methods: Straight filing Draw filing

When straight filing, the file is pushed lengthwise straight ahead or at a slight diagonal across the work. The file cuts on the forward stroke and is raised of the work on the return stroke. Dragging the file on the back stoke causes the teeth to dull out.

Draw filing produces a finer finish than straight filing. It is a convenient method for making smooth square edges on small surfaces or for accurately finishing flat surfaces. When using the draw filing method: The file is held firmly in both hands, at a right angle to the work. The file is then pushed and pulled across the work. Single cut files are most commonly used for draw filing.

Chisels Chisels are used to cut, shear, or chip cold metal. Chisels are used with a hammer in a two handed operation. One hand holds the chisel against the work. The other hand taps the hammer against the chisel to make the cut.

There are four common chisels in use. Flat chisel Cape chisel Round nose chisel Diamond point chisel The flat chisel is used for general cutting work. Commonly used to chip metal Cut thin metal sheets Cut rivets and bolts Flat Chisel

The cape chisel tapers to a narrow cutting edge and is designed to cut grooves and keyways in corners. The round nose chisel is used to cut grooves and to chip inside corners Cape Chisel Round nose chisel

The diamond point chisel is used to cut grooves and to square corners. It is square at the point and ground at the angle across the diagonal corners, making the cutting face diamond shape Diamond-point chisel

Hammer and mallet Hammers and mallets are striking tools and are used with chisels, punches and for other general striking tasks. Hammers are classified by the weight of the head, without the handle. Hammers are commonly made of steel or alloys, while mallet heads are normally made of leather, plastic, rubber, or wood.

Commonly used metalworking hammers are: Machinist’s hammer Riveting hammer Setting hammer Mallet Machinist’s hammer comes with either: Ball peen Straight peen Cross peen Ball peen hammers are most commonly used. Ball peen hammer

Riveting hammers are used to flatten seams and rivets Normally has a smaller head to eliminate damage to the surrounding metal. Setting hammers are also used to flatten seams and to flatten or form metal. Riveting hammer AKA: “Sheet Metal Hammer”

The mallet is used to apply light blows to materials that might be damaged by a heavier blow from a hammer. Setting hammer Rubber mallet

Screwdrivers Screwdrivers are used to tighten or loosen screws. There are two types of screwdrivers Flat head Phillips screwdriver Flat head screwdrivers have a straight, flat tip.

Choose a screwdriver whose blade fits snugly in the screw slots. A poor fitting screwdriver can damage the screw and screwdriver blades.

Pliers The primary purpose of pliers is to grip, but they are also used to cut and form metal. Slip joint pliers have an adjustable hinge, useful for holding different sizes of work. Needle nose pliers are used to hold work in tight spaces and to shape light metal and wire.

Diagonal pliers are used to cut wires, nails, pins, and screws. Utility pliers can hold large work in their parallel jaws and are ideal for heavy duty work.

Wrenches There are two common types: Adjustable Non Adjustable Adjustable wrenches have an adjustable jaw to accommodate different size nuts and bolts. Nonadjustable wrenches have a fixed opening.

Hand Punch The hand punch has either a point or blunt type. It is normally used to make: Indentations Mark locations of holes Knock out rivets Loosen pins Drive objects through metal

Punches used in metal work are: Solid punch Pin punch Prick punch Center punch The solid punch is used to make small diameter holes in light gage metal. It also can be used to knock out rivets after their heads have been cut off and to loosen pins.

The pin punch is used to drive the pins out of the holes in the metal. The prick punch is used to transfer measurements onto sheet metal. The center punch is used to start a hole to be drilled. The center punch will create a slight indentation in the metal to prevent the drill from wandering during the drilling process. The center punch point has a 90 degree angle.

Hand Snips Hand snips or “shears”, work much like scissors but cut metal. The blades on snips are either straight cut or combination cut. Sheet metal snips are usually color coded.

Red handled snips will cut metal with a right handed curve. Yellow handled snips will cut straight. Green handled snips will cut metal with a left handed curve.

Sheet metal snips are strictly used for cutting sheet metal only! They should not be used to cut bolts, wire, or anything else. This will ruin the blades and they are pretty much destroyed.

Shears After a layout is complete, the material is cut out of the metal sheet. In addition to the hand snips, several other hand operated machines are available for cutting sheet metal.

Throatless Shears Throatless shears are used extensively in sheet metal shops. This machine can be used to cut irregular and circular patterns.

Foot operated metal cutting shears These shears are a necessity in most sheet metal shops. They can cut up to 15 gage sheet metal. This machine is based on the maximum width of sheet metal the machine can handle.

Do not cut band iron, wire, or heavy gage metal on this machine. Sizes range from 30” and 36”. Do not cut band iron, wire, or heavy gage metal on this machine. Doing so will nick the blade, causing irregularities in the cut edge.

Forming Machines In addition to cutting and punching operations performed with snips, shears, and punches, metal can be formed into arcs, spirals, circles, cylinders and cones These machines vary from small hand operated forming rolls to larges motor driven bending rolls and forming presses.

Slip rolls forming machine This machine is used to bend sheet metal into a curved form. The sheet metal is formed by all three rollers. The front rollers grip the metal sheet and force it against the rear roller. This action bends the metal around the front upper roller, forming a cylinder.

The standard forming rolls are 18” wide. The distance between the geared rollers depends on the thickness of the metal. The distance can be adjusted by adjusting the adjustment screw on the lower front roller. Raising the rear roller will create a smaller radius and lowering it will from a larger radius. The standard forming rolls are 18” wide.

Powered slip rolls forming machine This machine is used for large production shops to perform the same function as the hand operated machine. It is used on 16 gage and lighter sheet metal

The roll drive is controlled by a toggle control. The covered foot pedal provides instant forward and reverse action. All three rolls are gear driven to ensure even starting and feeding of material.

Bar fold The bar fold bends sheet metal to make formed edges, seams, and hems. The machine clamps and folds in one motion. It is also used to form edges to hold wire. 45 degree and 90 degree bends can be made on bar folds.

Rotary Machine This machine is used to make edges on round and cylindrical objects. It contains rollers of different shapes. The rollers pull the metal piece through them, forming the edge. Very similar to using a hand operated can opener.

Crimpers The crimpers are used to reduce, or crimp the end diameter of one piece, allowing it to slide into another piece of pipe of the same diameter.

Brakes Sheet metal is usually bent to desired shapes using a brake. It is another important tool in sheet metal shops. It is used to straight bending on large pieces of sheet metal.

The press brake is a machine found in large shops that performs a wide variety of forming and bending operations. Metal is formed by pressing it into dies. They are not hand operated, but run on hydraulic or electric power.