FAQ - Elevator Bolts

How long of an elevator bolt do I need?  
  When installing buckets on an elevator belt, use this simple formula:  
  (belt thickness + bucket back thickness + washer thickness + nut thickness + 1/4 inch)  
     
What grade are 4B elevator bolts?  
  4B elevator bolts meet or exceed ISO Grade 5.8 / SAE Grade 2 standards.  The bolt grade guide below is for bolt diameters of 6mm (1/4") to 12mm (1/2"):  
     
BOLT GRADE GUIDE:

ISO Grade SAE Grade Min. Tensile Strenghth (psi)
5.8 2 74000
8.8 5 120000
10.9 8 150000


What torque setting should I use?  
  An ideal installation will result in the elevator bolt head fitting snuggly just below the surface of the belt after tightening (Image B).  However, never exceed the maximum recommended torque as shown in the tables below:  
     
MAXIMUM RECOMMENDED TORQUE FOR 4B ELEVATOR BOLTS METRIC ISO GRADE 5.8

Bolt Dia. in. lbs. ft. lbs. nm
M6 72 6 8
M7 115 10 13
M8 168 14 19
M10 336 28 38
M12 588 49 66


MAXIMUM RECOMMENDED TORQUE FOR 4B ELEVATOR BOLTS SAE GRADE 2 OR 302 STAINLESS STEEL

bolt dia. in. lbs. ft. lbs nm
1/4" 72 6 8
5/16" 156 13 18
3/8" 276 23 31
1/2" 684 57 77

 
How do you install an elevator bolt?  

  The head of the elevator bolt should lie against the inside surface of the elevator belt with the nuts and washers on the inside of the elevator bucket.  An ideal installation will result in the elevator bolt head fitting snuggly just below the surface of the elevator belt.    
     
           


     
  Do you have any maintenance recommendations?  
  After initial installation, it is recommended that the bucket elevator be run for approximately four hours.  After which the bolts should be re-tightened to ensure that there are no loose parts.  Periodic inspections are always recommended to  check for any issues that may occur during the life of the elevator, including checks for loose or damaged elevator bolts.