The two classes of angle-gauges now mentioned are those which are made of only one piece of steel, and those which are jointed and consist of two or three pieces for each gauge. To make one of a single piece of steel, the tool may be formed either by bending or by cutting the gauge from a piece of sheet steel. If it is to be made by bending, the piece selected is a small bar which is thicker than the intended arms of the gauge, and bent while thick; it is next reduced in order to thin and lengthen the arms to the proper length. When the gauge is to be made of a piece of sheet steel, the metal is marked while cold, and next heated to redness a few times to be cut out with chiselling on an iron block.

The angle-gauges termed hexagon gauges subtend an angle of one hundred and twenty degrees, and to adjust the arms of a gauge to this angle a circumference should be scribed and intersected in three places. A circle's circumference for this purpose is indicated by Fig. 507. In order to indicate the required angle, a circumference is scribed upon a plane surface, and with the same radius the circular line is cut in three places, which may be those shown in the Figure; a straight-edge is next put near to the point P and to the next place of intersection and a straight line marked, after which the adjoining straight line is marked by placing the straight-edge to the next point of intersection; these two lines are made of any length to suit the work and subtend the required angle of one hundred and twenty degrees.

Those gauges that are jointed are represented by Fig. 508, and are made with a thick shoulder-piece or pedestal, in one end of which is a joint-gap containing one end of a thin piece, which is the blade. The joint-gap is made with drilling and filing, the drilling being commenced at that place which is to be the bottom of the gap. The joint-pin for attaching the blade to its place may be either a rivet which is riveted tight enough to prevent unintentional shifting of the blade, or a small bolt, nut, and washer, the nut being a thumb-nut, that it may be easily worked with a finger and thumb. Of these two fastenings the rivet is most effective and simple, although not ornamental. The rivet-holes in such a gauge should both be coned, and the rivet while in its place should extend an eighth of an inch from each side of the pedestal; such a length will allow the blade to be tightened at a future time after becoming loose, and allow the burs made with riveting to be filed off. The only adjustment which jointed gauges require consists in making the blades and pedestals straight and rectangular, and filing the gap-sides parallel to the pedestal; if this is done, the broad sides of the blade will be parallel to the broad sides of the pedestal when both are riveted together.