Standard perimeter based pallet should normally overhang the front and rear beams by 50mm which ensures that the blocks of a pallet are always located over the beam. Thus:
· For a 900mm deep frame the required pallet depth is 1,000mm.
· For a 1,100mm deep frame the required pallet depth is 1,200 mm.
· For a 1,000mm deep pallet the frame should be 900mm.
· For a 1,200mm deep pallet the frame should be 1,100mm.
· The 50mm overhang is not necessary where suitable decking or pallet supports are fitted but the 50mm overhang must not be exceeded.
· For 2-way pallets the overhang and clearances are increased. (The 2010 SEMA guidelines make no distinction between 2 and 4-way entry pallets.)
The use of oversized pallets means that the blocks on the pallet are not supported over the beams with the bottom bearers taking the full load for which they are not designed and may easily fail as a consequence. Excessive pallet overhang can cause uneven weight distribution over beams, overload and damage the beam, or cause the pallet to become unstable and can also cause dislodgement of an adjacent pallet in back to back racking. The use of undersized pallets with inadequate overhang on the beam means there is greater risk of dislodgement.
For more information use this link: SEMA codes and tolerances explained.