Fig. 40...........Fig 41.
Figs. 40 and 41 make this point and its object clear. The saw, in Fig. 40, being stopped by A, naturally leads to the inference that A B is the timber's thickness. By running down the timber, as in Fig. 41, the saw's point sticking at a acts as a sure detector. This precaution should be taken on both sides (B and A) of the timber, and then, when the lags are screwed in, they can be sent home safe and true in the center of the timber.
It often happens that in boring for the lag screws the bit strikes a nail and further progress at that point seems out of the question. When so situated, take your bit out, and running the lag screw up as far as it will go, by sheer force swing it three or four turns up further than the point where your bit struck. Removing the lag and replacing the bit, it will be found that the nail has been forced aside and the way is now clear.
Fig. 42.
Hook bolts (Fig. 42) or—as our across-the-sea cousins call them—"elbow bolts," despite all assertions to the contrary, are an easy, safe and economical stringer fastener or suspending device.
Figs. 43 and 44 illustrate two very common abuses of the hook bolt. In the one (Fig. 43), instead of the bolt proper lying snug up against the beam flange with the whole of its hook resting squarely upon the beam's flange, its supporting countershaft is turned into a menace to limb and life by this "chance it" kind of erection. In the other (Fig. 44), though the bolts do lie snug against the flange, the hook being out of sight and no means being provided for telling whether the hook lies, as it should, at right angles to the web of the beam, even if properly placed at installation, timber shrinkage, vibration or a slight turn of the bolt when tightening the nut, all constitute dangerous factors tending to loosen or entirely loosen the hook's grip upon the beam flange.
Fig. 43.