integral with the movable jaw and a portion of a pinion meshing with it at the end of the handle. Pulling on the handle tightens the wrench on the nut and the harder one pulls, the more securely the nut is gripped. As moving the handle in the opposite direction spreads the jaws apart, a sort of a ratchet action is possible if the

handle is alternately pulled and pushed, rendering it unnecessary to take the wrench off and secure a new hold on the nut or bolt head for each turn. The wrench is composed of only three pieces and the smallest size will fit nuts varying from 1/4-inch to 3/4-inch. In order to unscrew a nut it is necessary to turn the wrench over so the handle will be pulled in the opposite direction to that used in screwing the nut down. This insures a secure grip in either case and permits of a ratchet motion without setting any trip or pawl. The hacksaw frame shown at Fig. 51, is a solid type adapted only to take one length of blade. As hacksaw blades are made in varying lengths it may be possible that a longer one than that frame was made for would be the only thing available. In such a case the adjustable hacksaw frame shown at Fig. 52, F, would permit of using a longer saw blade by merely extending the frame as far as is necessary.

Wrenches have been made in infinite variety and there are a score or more patterns of different types of adjustable socket and off-set wrenches. The various wrench types that differ from the more conventional monkey wrenches or those of the Stillson pattern are shown at Fig. 53. The "perfect handle" is a drop forged open end form provided with a wooden handle similar to that used. on a monkey wrench in order to provide a better grip for the hand. The "Saxon" wrench is a double alligator form, so called because the jaws are in the form of a V-groove having one size of the V plain, while the other is serrated in order to secure a tight grip on round objects. In the form shown, two jaws of varying sizes are provided, one for large work, the other to handle the smaller rods. One of the novel features in connection with this wrench is the provision of a triple die block in the centre of the handle which is provided with three most commonly used of the standard threads including 5/16-inch-18, 3-inch-16, and 11⁄2-inch13. This is useful in cleaning up burred threads on bolts before they are replaced, as burring is unavoidable if it has been necessary to drive them out with a hammer. The "Lakeside" wrench has an adjustable pawl engaging with one of a series of notches by which the opening may be held in any desired position.

Ever since the socket wrench was invented it has been a popular form because it can be used in many places where the ordinary open end or monkey wrench cannot be applied owing to lack of room for the head of the wrench. A typical set which has been made to fit in a very small space is shown at D. It consists of a handle, which is nickel plated and highly polished, a long extension bar, a universal joint and a number of case hardened cold drawn steel sockets to fit all commonly used standard nuts and bolt heads. Two screw driver bits, one small and the other large to fit the handle and a long socket to fit spark plugs are also included in this outfit. The universal joint permits one to remove nuts in a position that would be inaccessible to any other form of wrench, as it enables the socket to be turned even if the handle is at one side of an intervening obstruction.

The "Pick-up" wrench shown at E, is used for spark plugs and the upper end of the socket is provided with a series of grooves

into which a suitable blade carried by the handle can be dropped. The handle is pivoted to the top of the socket in such a way that the blades may be picked up out of the grooves by lifting on the end of the handle and dropped in again when the handle is swung around to the proper point to get another hold on the socket. The "Miller" wrench shown at F, is a combination socket and open end type, made especially for use with spark plugs. Both the open end and the socket are the same size and either may be used as is the most convenient. The "Handy" set shown at G, consists of a number of thin stamped wrenches of steel held together in a group by a simple clamp fitting, which enables either end of any one of the four double wrenches to be brought into play according to the size of the nut to be turned. The "Cronk" wrench shown at II, is a simple stamping having an alligator opening at one end and a stepped opening capable of handling four different sizes of standard nuts or bolt heads at the other. Such wrenches are very cheap and are worth many times their small cost, especially for fitting nuts where there is not sufficient room to admit the more conventional pattern. The "Starrett" wrench set, which is shown at I, consists of a ratchet handle together with an extension bar and universal joint, a spark plug socket, a drilling attachment which takes standard square shank drills from 1-inch to 1/2-inch in diameter, a double ended screw driver bit and several adjustments to go with the drilling attachment. Twenty-eight assorted cold drawn steel sockets similar in design to those shown at D, to fit all standard sizes of square and hexagonal headed nuts are also included. The reversible ratchet handle, which may be slipped over the extension bar or the universal joint and which is also adapted to take the squared end of any one of the sockets is exceptionally useful in permitting, as it does, the instant release of pressure when it is desired to swing the handle back to get another hold on the nut. The socket wrench sets are usually supplied in hard wood cases or in leather bags so that they may be kept together and protected against loss or damage. With a properly selected socket wrench set, either of the ratchet handle or T-handle form, any nut on the car may be reached and end wrenches will not be necessary.

Mention has been previously made of the importance of providing a complete set of files and suitable handles. These should be in various grades or degrees of fineness and three of each kind should be provided. In the flat and half round files three grades

are necessary, one with coarse teeth for roughing, and others with medium and fine teeth for the finishing cuts. The round or rat tail file is necessary in filing out small holes, the half round for finishing the interior of large ones. Half round files are also well adapted for finishing surfaces of peculiar contour, such as the inside of bearing boxes, connecting rod and main bearing caps, etc. Square files are useful in finishing keyways or cleaning out burred splines, while the triangular section or three-cornered file is of value in cleaning out burred threads and sharp corners. Flat files are used on all plane surfaces.

The file brush shown at 54, A, consists of a large number of wire bristles attached to a substantial wood back having a handle of convenient form so that the bristles may be drawn through the interstices between the teeth of the file to remove dirt and grease. If the teeth are filled with pieces of soft metal, such as solder or babbitt, it may be necessary to remove this accumulation with a piece of sheet metal as indicated at Fig. 54, B. The method of holding a file for working on plain surfaces when it is fitted with the regular form of wooden handle is shown at C, while two types of handles enabling the mechanic to use the flat file on plain surfaces of such size that the handle type indicated at C, could not be used on account of interfering with the surface finished are shown at D. The method of using a file when surfaces are finished by draw filing is shown at E. This differs from the usual method of filing and is only used when surfaces are to be polished and very little metal removed.

One of the most widely used of the locking means to prevent nuts or bolts from becoming loose is the simple split pin, sometimes called a "cotter pin." These can be handled very easily if the special pliers shown at Fig. 55, A, are used. These have a curved jaw that permits of grasping the pin firmly and inserting it in the hole ready to receive it. It is not easy to insert these split pins by other means because the ends are usually spread out and it is hard to enter the pin in the hole. With the cotter pin pliers the ends may be brought close together and as the plier jaws are small the pin may be easily pushed in place. Another use of this plier, also indicated, is to bend over the ends of the split pin in order to