Fig. 382.
Fig. 383.
[Figs. 382] and [383] represent two forms of hook bolt for use in cases where it is not desired to have bolt holes through both pieces of the work. In [Fig. 382] the head projects under the work and for some distance beneath and beyond the washer, as is denoted by the dotted line, hence it would suspend piece a from b or piece b from a. But in [Fig. 383] the nut pressure is not beneath the part where the hook d grips the work, hence the nut would exert a pressure to pull piece b in the direction of the arrow; hence if b were a fixed piece the bolt would suspend a from it, but it could not suspend b from a.
Fig. 384.
In woodwork the pressure of the nut is apt to compress the wood, causing the bolt head and nut to sink into the wood, and to obviate this, anchor plates are used to increase the area receiving the pressure; thus in [Fig. 384] a plate is tapped to serve instead of a nut, and a similar plate may of course be placed under the bolt head.