Scalpels Oil Paints British Police Helmets Ice Axes
Today on "how it's made"... Scalpels... Oil paints... British police helmets... And ice axes. The scalpel is the surgeon's trademark tool. Its short blade is razor-sharp and designed to slice swiftly and cleanly. This little knife may seem like a simple instrument, but its incredible precision, along with a surgeon's steady hands, is key to a safe and accurate medical procedure. Scalpel handles are made from rods of stainless steel. The blades are made of either carbon steel or stainless steel. They're sterile and designed for one-time use only. The blade steel is extremely thin, less than . 02 of an inch. It arrives at the scalpel factory in coiled strips. The first machine feeds the strips into a press. A die inside punches out unfinished blades, called blanks. Blades will vary in size and contour, but they all have the same center slot for attaching the handle. When you flex a blank, it bends entirely out of shape. That's because the steel still needs to be tempered. The blanks pass through a furnace for about 30 seconds. The heat alters the molecular structure of the metal, hardening it. Now the blank has the flexibility a scalpel blade requires. Next, the blanks move through a punching tool that pops them from the strip... And stacks them on a peg. A worker threads a metal ring through the slots to keep them together, then sends the whole set of blanks for surface polishing. This process will restore the metal's original sheen, which was dulled by the heat treatment. Next, workers visually inspect every blank, discarding any defective ones. They transfer the blanks from the ring to a metal rod using a gauge to measure out the right number. From here, the rods are mounted onto grinding machines. Each one picks up a blank with a magnet, then places it in a holder. The holder runs the blank against a wheel coated with diamond particles. This powerful abrasive shapes and sharpens a cutting angle, transforming the blank into a blade. As the blades come off the grinder, they cling together because the magnet that fed them into the machine magnetized them. To cancel this effect, a demagnetizing machine passes an electromagnet behind the stacks of blades. After a thorough washing in an ultrasonic cleaning tank, the blades move on to final inspection. Wearing protective rubber gear, workers carefully scrutinize the cutting edges, discarding any blade that's less than perfect. Each and every blade passes through two different inspectors. In the packaging department, a machine covers each blade with a brown paper strip that contains an anti-corrosion chemical. This provides extra protection against rust. A second machine slips each blade into a foil packet, then cuts the packets apart. Each packet bears the blade model number and tracking code. As the blades come off the packing machine, an inspector does one last quality check. Then he counts the blades and boxes them. Of course, it's critical that surgical blades be sterile, so the boxes go into a cobalt radiation chamber for about six hours. This obliterates any lingering contaminants. When the boxes exit the chamber, they're hospital-ready. In the operating room, it's simply a matter of sliding the blade onto the protruding part of the handle, called the bayonet. Surgeons make the most of their dexterity by choosing a handle that best fits their hands and best suits the procedure their hands will be performing. Coming up, mixing up a wide palette of colors at an oil-paint factory. Oil paint dates back to ancient times when artists mixed minerals and other elements with wax or oil. In the 1400s, they discovered that linseed oil was ideal as a pigment binder because it allowed blending and glazing in layers. Centuries later, the colors in those paintings are still vibrant. Today, many oil paint pigments still come from natural sources, though most are synthetically made. Factories buy both types of pigments in powdered form to make their paints. Cuttlefish ink yields brown pigment, lead produces a specific yellow, and mercury ore makes red. In the past, pigments have also come from stones, tree bark, plant gum, ground up glass, and even arsenic. This company's research laboratory spends about two years developing a color recipe. A chemist mixes specific amounts of linseed oil and pigment into a machine called an automatic mueller. It rubs the ingredients together, dispersing the pigment particles throughout the oil. For each sample, the formulation is altered slightly in search of the perfect result. The research team compares the resulting colors and selects the best one. To produce a color on a large scale, workers start by pumping a specified amount of linseed oil into a mixer. Then they add the precise amount of pigment. Most colors are made with just one pigment. The precise mixing time and speed depends on the kind of pigment formulation being created. Next, the mixture is spooned into a mill. Three dispersion rollers rub the ingredients, separating pigment particles and coating them in oil. The recipe specifies how much pressure the rollers apply, how fast they turn, and how long they work the mixture. Milling can take hours or even days, depending on the texture of the pigment. The quality-control lab takes samples from each batch coming off the mill and subjects them to a series of tests. Technicians scrutinize paint from both sides of the mill to ensure the mixture is being processed evenly. First, a spread test. A heavy brass weight goes onto a blob of paint for a prescribed period of time. Then, inspectors evaluate the volume of color and measure the distance it spread. If it doesn't spread far enough, it needs more milling. Next, a dispersion test. The markings on this gauge indicate the size of the paint's particles in microns, millionths of a meter. If the particles are too big, the paint hasn't been milled enough. Finally, inspectors time how long it takes the paint to dry to the touch. Each color has a specified drying time, ranging from two days to two weeks. The factory produces a chart that displays its 120 paint colors. Workers brush each color onto a primer-coated paper. When the paint dries, they cut each bar into rectangular swatches called chips. The chart is assembled using this mounting machine. The bottom has a section for chips of each color. And the top contains a cardboard chart coated in glue. As the machine closes, each chip aligns perfectly with its designated spot on the chart. Back in the production line, the factory packages one color at a time in toothpaste-style tubes that will be finished off with twist caps. Once the labels go on, the tubes make their way to the filling machine. There, the tubes have their tops screwed on. A nozzle squirts in the paint. Then clamps flatten the edges shut. A roller folds over the edge to strengthen the seal against squeeze pressure. Now these oil paints are finally ready to meet the canvas. When we return, a new twist on the traditional british police helmet. British bobbies are used to standing tall because of their distinctive hats. These traditional police helmets are almost a foot high. That added height can't hurt when you're staring down a bad guy. Bobbies' helmets have looked the same way for a century and a half. Today, hatmakers use a metal mold to create that signature shape in fortified plastic. The mold descends into an oven. A worker places a sheet of plastic overhead. He lowers the lid and slides the heated cover over it. It takes a couple of minutes for the heat to soften the plastic. The mold rises. A vacuum below pulls the plastic into shape. It hardens almost instantly. A firm tap with a rubber mallet releases the shell from the mold. A band saw slices away the excess plastic along the brim. And now the helmet is ready to be covered. For that, the factory uses water-repellant wool. The helmet pattern is cut out in two pieces. These halves are stitched together, making a raised seam, which gives the helmet a smoother line. The insides of the fabric covers are covered with glue. Then they're steamed. A coating of glue is brushed all over the helmet's shell. The fabric cover has now reached the perfect dampness, making it easier to pull over the glued surface of the plastic helmet shell. The fabric gets stretched a bit so it'll fit tightly without buckling. Then, a wooden tool is used to smooth away any remaining air bubbles. The excess fabric is trimmed away. Then, rubber piping is sewn around the brim to reinforce it and give it a neater edge. The prong ends of the helmet's decorative metalwork are dipped in a chalky powder, which mark its positioning on the crown. Holes are drilled through the markings. Then the ornament is installed and its prongs are folded against the inside of the helmet. Next, workers stitch together strips of tape, plastic, and foam to make the helmet's harness and chinstrap. They fit the harness assembly inside the helmet, then secure it with an industrial stapler. Metal banding is wrapped around the helmet and pinned down. Not only does this banding hide the staples, it gives the helmet a snazzier look. An ornate helmet plate featuring the police department's insignia goes on the front. Next, a sponge liner is tucked inside the helmet to protect the officer in the event of a blow to the head. Ventilation holes are punched in the sides. Now it's time to size the helmet with a special gauge. Any excess fluff is tweezed away and the wool is brushed to bring up the pile. Finally, workers attach the label that assures the product meets all specifications. This police helmet is now ready to report for duty. It takes about half an hour to make one of these helmets, but it should keep a bobby on the beat safe and stylish for much, much longer. Up next, ice-axe production begins with a little heat. When it comes to mountain climbing, the ice axe is a fundamental tool. Ice axes were invented in the mid 19th century to help mountaineers get a grip on slippery slopes, pull themselves to the summit, and stop a fall. They're designed for peak performance. Talk about a steep learning curve. Climbing with an ice axe takes a bit of practice and a lot of courage. Production of an ice axe starts with an aluminum rod. A powerful press bends it into a curve, giving it the basic contour of an ice axe. It's flattened and shaped in two fiery dies. Each die has a top and a bottom half, which are lubricated between forgings. The hot forging transforms the metal rod. It starts to look a lot more like the shaft of an ice axe. The long ridges add strength to the metal while other indentations mark where the attachments are to go. The forging creates a lip around the perimeter of the shaft. They call this excess metal flash. This press takes care of it in a snap. Now, the ice-axe shaft has a cleaner edge and it's quite a bit lighter than the original rod, an advantage when you're toting it up a mountain. That aluminum rod has gone through quite a few stages, and now it has a whole new profile. This tub of vibrating ceramic cones will smooth the shaft's rough edges. Here, a computerized drill makes holes into recesses that were stamped into the shaft earlier. These holes will be used to attach other parts. The machine changes the drill bit to a circular blade. Then, guided by the computer, it cuts a slot for the ice-axe pick. Next, the saw moves to the other end and thins out the area where the handle will be attached. Using another drill bit, the saw carves out a hole for the adjustable finger rest. Here's a shaft that's already been milled and drilled compared with one yet to undergo the process. The shaft gets a protective coating. Then, it's time to bring all the pieces of the ice axe together. A worker applies epoxy to the inside of the rubber handle and slides it onto the shaft. The handle has an open end. He beads a little more epoxy onto it and inserts a steel spike. The spike is then riveted to the ice-axe shaft. This spike will come in very handy on the mountain side. Plunging it into a snowy slope can help a climber maintain his or her balance on a slippery uphill trek. Next, the adz slides into the slot at the head of the shaft. Climbers use this tool to chop steps in hard snow and ice. The worker secures the adz with nuts and bolts, and then he installs the pick. This hooked and jagged attachment will help get the climber up a mountain of hard ice. The bolts are tightened with a torque wrench. After all, a solid job here could be a lifesaver. And finally, the adjustable finger rest is screwed to the shaft just above the handle. And now you have a tool that can help you scale new heights.