Pallet Rack Load Capacity & Design Criteria
Unarco Racking pallet rack beams and upright frames are engineered to current Rack Manufacturers Institute (RMI) specifications (ANSI MH16.1) and AISI Cold-Formed Steel Design Manual standards. All capacities represent uniformly distributed gravity loads taking into consideration deflection limits and material stress.
ANSI MH16.1 / RMI Specification Regarding Frame Tables
Standard upright load tables represent column capacity under purely axial, symmetrical gravity loading. In real-world installations, slab thickness, seismic design categories (Ss > 25%g), beam elevation spacing, and impact factors require site-specific PE engineering review. Contact Unarco Racking engineers at [email protected] to obtain certified calculations for your project.
Roll-Formed Step Beam Capacities (Pounds Per Pair)
Deflection Limit: L/180| Beam Length | Part Number Example | Profile & Gauge | RMI Capacity (Lbs/Pair) |
|---|---|---|---|
| 48" (4 ft) | F2 6356 04800SSS000 | 3.56" Height – 16 Gauge | 7,991 lbs |
| 60" (5 ft) | F2 6356 06000SSS000 | 3.56" Height – 16 Gauge | 6,544 lbs |
| 72" (6 ft) | F2 6356 07200SSS000 | 3.56" Height – 16 Gauge | 5,573 lbs |
| 96" (8 ft) | F2 6250 09600SSS000 | 2.50" Height – 16 Gauge | 2,126 lbs |
| F2 6331 09600SSS000 | 3.31" Height – 16 Gauge | 3,452 lbs | |
| F2 6356 09600SSS000 | 3.56" Height – 16 Gauge | 3,972 lbs | |
| F2 6400 09600SSS000 | 4.00" Height – 16 Gauge | 5,009 lbs | |
| F2 6450 09600SSS000 | 4.50" Height – 16 Gauge | 5,832 lbs | |
| F2 6500 09600SSS000 | 5.00" Height – 16 Gauge | 6,730 lbs | |
| F2 4600 09600SSS000 | 6.00" Height – 14 Gauge | 9,897 lbs | |
| 108" (9 ft) | F2 6356 10800SSS000 | 3.56" Height – 16 Gauge | 3,206 lbs |
| F2 6400 10800SSS000 | 4.00" Height – 16 Gauge | 4,044 lbs | |
| F2 6450 10800SSS000 | 4.50" Height – 16 Gauge | 5,184 lbs | |
| F2 6500 10800SSS000 | 5.00" Height – 16 Gauge | 6,038 lbs | |
| F2 4600 10800SSS000 | 6.00" Height – 14 Gauge | 8,842 lbs | |
| 120" (10 ft) | F2 6356 12000SSS000 | 3.56" Height – 16 Gauge | 2,649 lbs |
| F2 6400 12000SSS000 | 4.00" Height – 16 Gauge | 3,329 lbs | |
| F2 6450 12000SSS000 | 4.50" Height – 16 Gauge | 4,254 lbs | |
| F2 6500 12000SSS000 | 5.00" Height – 16 Gauge | 5,353 lbs | |
| F2 4600 12000SSS000 | 6.00" Height – 14 Gauge | 7,997 lbs | |
| 144" (12 ft) | F2 6400 14400SSS000 | 4.00" Height – 16 Gauge | 2,377 lbs |
| F2 6450 14400SSS000 | 4.50" Height – 16 Gauge | 3,021 lbs | |
| F2 6500 14400SSS000 | 5.00" Height – 16 Gauge | 3,785 lbs | |
| F2 4600 14400SSS000 | 6.00" Height – 14 Gauge | 6,369 lbs | |
| F2 2600 14400SSS000 | 6.00" Height – 12 Gauge | 8,979 lbs |
Structural Channel Beam Capacities (Pounds Per Pair)
Hot-Rolled Structural Steel| Length | C3 x 3.5# | C4 x 4.5# | C4 x 5.4# | C5 x 6.7# | ||||
|---|---|---|---|---|---|---|---|---|
| W/O Tie | W/ Tie | W/O Tie | W/ Tie | W/O Tie | W/ Tie | W/O Tie | W/ Tie | |
| 48" | 12,593 | 12,858 | 16,000 | 16,000 | 16,000 | 16,000 | 16,000 | 16,000 |
| 72" | 7,577 | 8,680 | 10,801 | 14,074 | 12,917 | 15,132 | 16,000 | 16,000 |
| 96" | 4,777 | 5,068 | 6,904 | 10,263 | 7,908 | 11,048 | 11,676 | 16,000 |
| 108" | 3,821 | 4,070 | 5,541 | 8,493 | 6,246 | 8,903 | 9,155 | 14,577 |
| 120" | 3,132 | 3,345 | 4,417 | 6,928 | 5,062 | 7,255 | 7,373 | 12,867 |
| 144" | 2,220 | 2,379 | 3,070 | 4,865 | 3,517 | 5,084 | 5,072 | 9,395 |
All rated values assume two uniformly distributed pallet loads across each shelf pair, with 50% load supported by each beam.
Maximum allowable vertical deflection for industrial beams is specified as beam length divided by 180 (L/180) under design load.
Values include 12.5% impact for 2 pallets side-by-side. For 3 pallets per pair, multiply by 0.95. For 1 concentrated pallet, multiply by 0.90.
Roll-formed beams longer than 150" require lateral ties. Structural channels exceeding 108" span mandate approved lateral ties to maintain rated capacity.
Upright Frame Capacities – Open C-Section & SuperPost Closed-Tube
Upright frame load carrying ability is governed by the maximum unsupported length — measured as the vertical clear distance from the floor to the top of the first shelf level, or the maximum vertical spacing between beam elevations (whichever is greater).
| Unsupported Length | Standard 3"x3" 14 Ga. | Standard 3"x3" 12 Ga. | SuperPost 3"x3" Closed Tube | SuperPost 4"x3" Heavy-Duty |
|---|---|---|---|---|
| 36" Beam Spacing | 23,323 lbs | 42,237 lbs | 51,476 lbs | 84,401 lbs |
| 48" Beam Spacing | 19,030 lbs | 32,983 lbs | 46,644 lbs | 76,108 lbs |
| 60" Beam Spacing | 15,902 lbs | 26,684 lbs | 34,747 lbs | 66,632 lbs |
| 72" Beam Spacing | 12,927 lbs | 21,007 lbs | 26,519 lbs | 56,637 lbs |
| 84" Beam Spacing | 10,249 lbs | 16,263 lbs | 19,582 lbs | 46,740 lbs |
| 96" Beam Spacing | 8,269 lbs | 12,893 lbs | 14,993 lbs | 37,424 lbs |
Note: Frame capacities apply to plumb, undamaged columns anchored to concrete with minimum compressive strength of 3,000 PSI. Applications exceeding 31,000 lbs frame load or subject to seismic design require certified review by Unarco Racking engineering.
Key Factors That Affect Pallet Rack Load Ratings
- First Beam Elevation: Increasing the distance between the warehouse floor and the bottom beam significantly reduces total upright carrying capacity by extending unsupported column length.
- Concrete Slab Strength & Embedment: Upright base plates require adequate anchor bolt embedment into qualified concrete slabs to resist overturning and seismic lateral forces.
- Configuration Alterations: Removing or adjusting beam levels in existing racking changes column unbraced lengths, which can void original engineered capacity ratings.
- Accidental Forklift Impact: Dented or bent upright legs must be inspected immediately; structural upright damage compromises rated safety factors.