A tee-square which is made of two pieces, consists of the blade and its pedestal, and in this pedestal a gap is made in the mid-part to contain one end of the blade; such a gap is shown in Fig 488, and the blade is denoted by Fig. 489. The two pieces are first securely riveted together, previous to adjusting the tool, as in the making of other squares; and if the blade of a tee-square is straight and parallel, and the gap exactly at right angles to the length of the pedestal, both blade and pedestal may be reduced to very near their finished dimensions previous to riveting together.

To forge a solid tee-square of one piece, a piece of steel is provided which is twice as thick as the intended pedestal; the steel is first fullered and reduced at both ends to form a lump in the mid-portion, at which time the piece resembles Fig. 490; the lump in the middle is next fullered either at both sides or one side, to commence the reduction to form the blade; if fullered at both sides to cause the blade to extend from the middle of the pedestal, instead of from one side, the work appears as in Fig. 491, but if the blade is to be in the same plane with one side of the pedestal, the lump is fullered at only one side. After this operation, the fuller is also driven in at right angles to its former position, in order to make two other hollows at right angles to the two or one first made; and when thus hollowed, the piece for the blade appears to be united to the pedestal with a square neck, as seen in Fig. 492 ; while in this condition the thinning and lengthening of the lump is commenced, and when partly reduced to the required size, the fullers are again driven in a short distance, after which the thinning of the blade is again resumed, and by such reducing the blade is made of a sufficient length.

A tee-square may be forged also by using a thick bar and forming a stem at one end, as seen in Fig. 493. After this stem for the blade is produced, the entire «piece for the square is cut from the bar, and the thicker part is spread and lengthened at each side of the stem first made to form the two arms of the pedestal, this lengthening being effected with hammering on the anvil, and also by hammering the pedestal while the blade extends through the hole in a heading-tool having a square hole. By these means the pedestal is first formed; after which the stem for the blade is fullered and then lengthened to its dimensions.

A centre finder, which consists of a tee-square having two pins extending from one side of the pedestal, is made of either one or two pieces; and when roughly made into a square, the two pins are fixed by screwing them tight into two screwed holes made entirely through the pedestal. The screw-parts of these pins are larger in diameter than the straight-ends which are to project outside, and the holes are also tapered to allow the screws to be riveted after being screwed into their places. In order to place the pins at right angles to the length of the blade, and in their proper places, an arc is marked upon one side of the pedestal. When the centres of the pins are to be equi-distant from the centre length of the blade, an arc is exscribed from the centre shown by C, in Fig. 494; and when the centres of the pins are to be equi-distant from one side of the blade an arc is exscribed from the point denoted by P, in Fig. 495. In both these Figures the two places in the mid-line of the pedestal that are intersected by the arcs are the places for the holes, and indicated by H and H. These places are marked with a dotting punch, and from the dot a small circle is marked which is about a sixteenth larger in diameter than the hole to be drilled. This small circular line is a guide or sort of indicator during the entrance of the drill's point, and if the workman observes that the drill is nearer to one extremity of the circle than to the opposite extremity, he takes out the drill when it has entered only a short distance, and endeavours to put the drill point into its proper place. This is effected with a gouge chisel, which the operator drives in at that side of the recess towards which the drill's point should be brought; by this means the chisel cuts out sufficient metal to make the drilled recess concentric with the small circular line, at which time the drilling is resumed and watched, and, if necessary, the gouge is again applied as before. By this method the holes are made very near to their required places, and when drilled, screwed, and the pins are tightly riveted in, the entire tool is smoothed and adjusted to make the length of the blade exactly at right angles to a line which connects the centres of the two pins. This final adjustment is effected with filing and scraping both the pins, and also the blade and pedestal; for this reason the two pins are thicker when put into their places than they will be when finished, in order to avoid taking a large quantity from the blade or pedestal.

Cross-Squares

A cross-square is made by forging two separate pieces, one being the blade and the other being the thick shoulder-piece, or pedestal; this portion is forged solid, and with a flat-sided lump in the middle, in which the small slot is to be made for the blade. A piece of this form is shown by Fig. 496, and through the lump having a flat side instead of a curved one, the piece can be firmly placed while drilling the slot. The drilling is effected by advancing the drill to about half way through from both entrances ; and after the drilling and filing is performed, the lump is curved to a semicircular form, and the blade is tightly fitted to its plate. While the blade is thus fixed, both pedestal and blade are adjusted to place them at right angles with each other, and also to make the length of the pedestal at right angles to the slot; consequently, the slot and blade are finished previous to finishing the shoulder of the pedestal.