Basic hand tools : screwdrivers, hammers, pliers and wrenches (1983)

foreign [Music] there is a growing need for workers with the skills to maintain and repair complex machines using basic hand tools this film will illustrate some of the most frequently used hand tools and demonstrate their correct usage let's begin with one of the most basic tools of all the screwdriver there are three common types the blade screwdriver fits screws having a single slot the Phillips type screwdriver fits screws which have two Crossing slots depositorx screwdriver fits screws that have slots that look like this each of these types of screwdrivers comes in an assortment of sizes it's important to choose the correct size for the job the blade should be the same width as the screw head and thick enough to fit the slot snugly if you use a poorly fitting screwdriver you may damage both the slot and the blade tip using the wrong size Phillips screwdriver produces equally damaging results it's just as important to use the right type of screwdriver if you use a positorx screwdriver on a Phillips screw this could happen so always use the type and size of screwdriver that fits the screw slot properly and to maintain the fit always keep the screwdriver vertical to the screw never try to drive the screw at an angle avoid using screwdrivers for prying you may bend the shank or break the blade making the tool useless for frying jobs use a pry bar it's made for such work and can take the strain the hammer is another basic and well-known hand tool the ball peen hammer is used for such jobs as riveting the claw hammer is used to drive and pull Nails in carpentry work special hammers with plastic rubber or Rawhide heads are available for use on surfaces which could be damaged by an ordinary hammer here you see the correct way to grip any Hammer the hand grasps the handle near the end this grip provides maximum Leverage and allows you to strike the object with the full face of the hammer avoid gripping the handle close to the hammer head this reduces the force of the blow and causes the hammer to strike at an improper angle you can increase the accuracy of your aim by resting the hammer on the object before drawing back for a strike never use the end of the handle for hammering this can split and ruin the wooden handle tools used to tighten or loosen nuts and bolts are called wrenches open end wrenches are commonly used on cable ends and hose connectors most open end wrenches have the head opening at a 15 degree angle to the body this makes the wrench more efficient in places where its space is limited you can turn the wrench over after each stroke this reverses the angle of the opening so it fits the next two sides of a six-sided nut thus you can keep turning the knot even though the swing of the wrench is limited always make sure an open end wrench fits tightly on the nut or bolt head if the wrench is even slightly too large it will slip off when you apply Force unlike the open end wrench the heads of the six point and 12 point box wrenches completely surround or box the nut or Bolt 12-point box wrenches are particularly useful in very small spaces because they're 12 Point opening allows you to continuously turn a knot with as little as 15 degrees of Arc one disadvantage of the Box wrench is that it must be lifted off the nut and repositioned after each stroke therefore many mechanics use the Box wrench only when they begin loosening or finish tightening a knot the rest of the time if there is working room they use an open end wrench because it can screw the nut much more quickly than the Box wrench for this reason some mechanics prefer combination wrenches which have a box wrench on one end and an open end wrench on the other of course when there is sufficient clearance to spin a box wrench in a full circle there's no advantage in switching to an open end wrench when you must tighten or loosen a number of knots you can usually save time by using a socket wrench a special mechanism inside the ratchet handle allows you to turn the knot in One Direction and Ratchet the handle back for another stroke without raising the socket off the nut for this reason you can turn the knot very rapidly a lever on the ratchet handle changes the direction of ratcheting so the tool can both loosen and tighten nuts socket wrenches are sturdy tools but never hammer on them or use a pipe to increase Leverage you could damage the ratcheting mechanism in addition the toolbox of a well-equipped mechanic will contain at least one or two adjustable wrenches for use on odd size Nuts and Bolts this tool is similar to an open end wrench but has an adjustable jaw the wrench is placed on the nut and the adjusting knurl is turned to tighten the jaw on the nut the wrench should always be placed on the nut so that the pulling force is applied to the fixed jaw as shown here no matter what kind of wrench you use remember this rule whenever possible pull on the wrench don't push pushing on a wrench to loosen a tight nut can be hazardous a lesson many novice mechanics have learned the hard way on those rare occasions when you must push on a wrench use the base of the Palm with your hand open Pliers are tools you will use on many mechanical and electrical repair jobs these are some of the most common types they're all simple and easy to use tools channel lock pliers can adjust to two or more positions for gripping small or large objects they are multi-purpose pliers often used for grasping clamps and cables and for turning round Fasteners such as hose couplings diagonal cutting Pliers are useful for pulling and installing cotter pins their sharp diagonal Jaws make it easy to spread the ends of the cotter pin and cut it to the right length long nose pliers are used for bending wire and for working with small objects in hard to reach places most long nose pliers have a side cutter which you can use to cut thin wires but to cut heavy gauge wire you will need to use lineman's pliers which are specially designed for this purpose one final point never use pliers to tighten or loosen nuts this can damage the pliers Jaws always use a wrench on nuts this film has demonstrated the correct usage of several basic hand tools what you have learned will make you more skillful at a variety of Maintenance and Repair jobs foreign