Expansion bolts are also made with all the parts entirely of brass or bronze, with either plain, capped, or fancy heads, or nuts, and in any finish desired.
11. Screw Anchors.—The device known as a screw anchor can be used in place of an expansion bolt for securing light materials. Several kinds of screw anchors are in the market at present. The star anchor, which is made in one piece of composition metal that is slotted about seven-eighths of its length, may be obtained in various diameters and lengths. The exterior has two star-like projections, to prevent the anchor from turning, while the interior is constructed of ridges projecting from the tube, with the hole reduced toward the slotted end. This internal construction permits the star anchor to be used in combination with trade wood or machine screws of any length. The screw used engages with the ridges in the interior, cutting its own thread and expanding the anchor in its passage. These composition anchors are very cheap, the price ranging from 1 to 3 cents, according to the size. They are made in different lengths, from ½ inch to 1½ inches, and for Nos. 6, 10, 14, and 18 wood screws.
Fig. 9
12. Special Bolts.—In [Fig. 9] is shown a toggle bolt. This device is a recent production for fastening materials to surfaces having a hollow interior that will not admit the use of expansion or tap bolts because of its frail character, as, for instance, sheet metal, hollow fireproofing, etc. The toggle bolt shown in the figure is constructed with long, fine-pitch threads cut nearly to the head, so as to allow for securing thin materials. The T-shaped head a is constructed either hollow, as shown in the figure, or of flat strip metal, and is riveted loosely to the end of the bolt, allowing the head to pivot and fold over the bolt, and thus permitting the head to pass through a small opening. The head is then tipped into its proper position, when the bolt is ready for securing in place the work to be fastened. The construction of the bolt is shown in [Fig. 9 (a)], while the process of affixing it is illustrated at (b) and (c). These toggle bolts are generally made with ³/₁₆-, ¼-, and ⁵/₁₆-inch bolts, from 2½ to 6 inches long, and of either iron, steel, or brass.
SASH WEIGHTS
13. Cast-Iron Weights.—The term sash weight is applied to a counterweight used for balancing double-hung, or sliding, sash. These weights are generally very rough, being made from either the poorest iron or waste iron. The stock sizes are usually long and cylindrical in form—from 1⅜ to 2¼ inches in diameter—have an eye cast in the upper end, as shown in [Fig. 10], and weigh from 2 to 30 pounds, the weight determining the length of the sash weight. In [Table V] are given the weight, diameter, and length of sash weights as they are generally furnished to the trade, although it is almost impossible to give this data with any degree of accuracy, as the different manufacturers vary the diameters of the weights slightly, and this changes the length measurement. Square weights or special weights can be easily procured at small additional cost.
Fig. 10
