Blade Grip Bolts and Nuts Torque Specifications – November 27, 2012
GRIP BOLTS AND NUTS TORQUE SPECIFICATIONS:
There are two types of nuts that have been supplied to secure the 3/8-24 blade grip bolts. The torque applied to the nuts is dependent on which nut you are using. The first type which was supplied is a non-locking nut which is identified by two six sided shapes on the flange of the nut. The second type is a lock nut that can be identified by an “L” shape on the flange of the nut and three crimped areas it the head of the nut.
The non-locking nut will be torqued to 50 foot-pounds while the locking nut will be torqued to 34 foot-pounds. This may seem unusual as one would assume that the locking nut would have more prevailing torque but this is not the case. The high quality finish and thread lubrication of the locking nut allow it to thread tighter with less drag and hence, less torque. The clamping force generated using either nut exceeds 9,000 pounds.
The bolts are more prone to failure if they are over-torqued. Locking type nuts are not to be re-used once removed as the thread lubrication will be degraded and alter the torque required in ways that can not be accurately measured and compensated.
PHOTOS OF THE NUTS FOLLOW: