Technical terms per letter "N"
Neck (of a hook) is a place where a hook shank goes to the thread (before the first threads). It is the usual place where a hook brakes and thus requires the most careful control during operation.
Non-drive crane wheel (driven) is a floating wheel which rotates about its axes
Non-standard crane wheels Non-standard wheels are those for the production of which forged blanks (forgings) are used. Such wheels include all crane wheels with the tread surface diameter (D) up to 300 mm (260Х70, 260Х80, 200х60, 250х70). Also a forging is used, if crane wheel parameters h and L1 are impossible to be entered into output settings of a stamping.
— h, hub wall thickness. This parameter of a finished wheel may not be less than it is regulated by GOST 28648-90. If the desired fitment bore size is larger than a stamping can allow without breaking GOST norm then a forging is used.
— L1, Fitment bore diameter - the diameter of the bore that the blank already has is taken into consideration while choosing a stamping for production of a specific dimension type of a crane wheel; you cannot produce a crane wheel with a fitment bore diameter smaller than the stamping already has. In this case when a wheel does not match to this stamping parameter, then a forging is used.
— h, hub wall thickness. This parameter of a finished wheel may not be less than it is regulated by GOST 28648-90. If the desired fitment bore size is larger than a stamping can allow without breaking GOST norm then a forging is used.
— L1, Fitment bore diameter - the diameter of the bore that the blank already has is taken into consideration while choosing a stamping for production of a specific dimension type of a crane wheel; you cannot produce a crane wheel with a fitment bore diameter smaller than the stamping already has. In this case when a wheel does not match to this stamping parameter, then a forging is used.