Fig. 397.
When it is desirable to provide that bolts may be quickly removed, the flanges may be furnished with slots, as in [Fig. 396], so that the bolts may be passed in from the outside, and in this case it is simply necessary to slacken back the nut only. It is preferable, however, in this case to have the bolt square under the head, as in [Fig. 397], so as to prevent the bolt from turning when screwing up or unscrewing the nut. The bolt is squared at a, which fits easily into the flange. The flanges, however, should in this case be of ample depth or thickness to prevent their breakage, twice the depth of the nut being a common proportion.
Fig. 398.
Fig. 399.