There are quite a few factors that go into determining which Unistrut channel is right for your application, things like finish requirements, how it will be installed, and of course, weight capacity. 

The weight limit of a single channel profile can vary by over 1000 lbs depending on factors like the span of the channel and how it is supported, how many slots and holes are in the channel, and the position of the load. To find the Unistrut channel that can support your requirements, you need to complete a few calculations.

How to Find the Weight Limit of Unistrut Channel

To find out how much weight a specific profile of Unistrut channel can hold, you first need to gather some information.

Each Unistrut channel has a beam loading table that can be found in the General Engineering Catalog. That table will tell you the maximum allowable uniform load (in pounds) of a specific span of that channel. To find the weight limit of a channel in your specific application, you will need to know the following information: 

• The type of Unistrut channel being used
• The desired span of the channel in inches
• If the channel is pierced and if so, which series
• If the channel will be adequately laterally braced and if it is unbraced, the span of the unbraced sections in either feet or inches
• If your design calls for a concentrated midspan point load
• The weight of your applicable Unistrut channel

Following the instructions laid out by Unistrut, you can use the above information alongside the appropriate beam loading table to find out the weight capacity of your Unistrut channel.

Tips for Reading Unistrut Beam Loading Tables

Unistrut provides beam loading tables for all channel profiles in the General Engineering Catalog. Be sure you’re referring to the correct table when making your calculations. 

When calculating your beam load, remember that the provided tables help calculate the total uniform load (W Lbs), not uniform load (w lbs/ft or w lbs/in). To find the uniform load (w lbs/ft or w lbs/in), divide the load by the span. 

The table also includes columns with values for uniform loading at deflection for structures that require limited deflection or sag. These columns utilize standard engineering practice ratios of span/180, span/240, and span/360. If your build requires designing to one of these deflection limits, use the appropriate value in place of the maximum allowable uniform load measurement.

How to Calculate How Much Weight a Unistrut Channel Can Support

Step One:

Determine the maximum allowable uniform load from the load table based on your desired span in inches and if you are designing to deflection limit

Step Two:

If your channel is pierced, multiply the maximum allowable uniform load found in Step One by the following factor:

• “KO” Series: 95%
• “T” Series:85%
• “HS” Series: 90%
• “SL” Series: 85%
• “H3” Series: 90%
• “DS” Series: 70%
• “WT” Series: 85%

Step Three:

If your channel is unbraced, use the Lateral Bracing Load Reduction Chart from page 62 of the General Engineering Catalog to multiply your maximum allowable uniform load by the applicable unbraced length factor.

Step Four:

Subtract the channel weight from your calculated maximum allowable uniform load

• This result is the net allowed total uniform load in pounds

Step Five:

If you have a concentrated midspan point load, multiply the beam load by 50%

• This result is the allowed midspan point load 

Unistrut Channel Weight Limits

P1000 Weight Limits

Based on the numbers in the P1000 beam loading chart, the maximum allowable uniform load for a P1000 channel is anywhere from 170 lbs to 1690 lbs. To figure out the actual weight limit of your P1000 channel, we have to do the above calculations.

As an example, let’s say we’re looking to find out how much weight a 120-inch span of unpierced P1000 channel with no concentrated midspan point load can hold.

Step One:
Determine the maximum allowable uniform load from the load table based on your desired span in inches and if you are designing to deflection limit.

• 340 lbs

Step Two:
Our channel is unpierced so we do not need to multiply by any factor

Step Three:
Our channel is appropriately braced, so we do not need to multiply by the unbraced length factor.

Step Four:
Subtract the channel weight (189 lbs/100 ft) from your calculated maximum allowable uniform load.

• 340 lbs - 18.9 lbs = 321.1 lbs
• 321.1 lbs is our net allowed total uniform load

P1001 Weight Limits

Based on the P1001 beam loading chart, the maximum allowable uniform load for a P1001 channel (prior to any additional calculations) is 480 lbs to 3500 lbs. The actual weight limit for your channel will depend on completing the above calculations.

P5500 Weight Limits

Based on the P5500 beam loading chart, the maximum allowable uniform load for a P5500 channel is between 330 and 3270 lbs. Complete the required calculations to determine the weight limit of your specific P5500 channel.

P5501 Weight Limits

Based on the P5501 beam loading chart, the maximum allowable uniform load for P5501 channel is 960 to 5220 lbs. To find the weight limit for your application, complete the required calculations. 

P5000 Weight Limits

Based on the P5000 beam loading chart, the maximum allowable uniform load for P5000 channel ranges from 530 lbs to 5260 lbs. The weight limit for your specific application is dependent on the required calculations. 

P5001 Weight Limits

Based on the P5001 beam loading chart, the maximum allowable uniform load for P5001 channel is between 1610 lbs and 6890 lbs. Complete the required calculations to determine the weight limit of your P5001 channel application.

P3300 Weight Limits

Based on the P3300 beam loading chart, the maximum allowable uniform load for P3300 channel is 120-600 lbs. The weight limit of your application of the P3300 channel can be calculated using the above steps. 

P3301 Weight Limits

Based on the P3301 beam loading chart, the maximum allowable uniform load for P3301 channel ranges from 280 lbs to 1690 lbs, depending on the span. You can determine the weight limit of your P3301 channel using the provided calculations. 

P4100 Weight Limits

Based on the P4100 beam loading chart, the maximum allowable uniform load for P4100 channel is 50-450 lbs, depending on the span. To find the weight limit for your P4100 application, complete the required calculations.

P4101 Weight Limits

Based on the P4101 beam loading chart, the maximum allowable uniform load for P4101 channel is 120 lbs to 1090 lbs. To find the weight limit for your P4101 application, complete the required calculations. 

Below is a high-level reference chart for calculating the weight Unistrut channels can hold.

Turn to Unistrut Midwest’s Engineering Support 

The margin for error is practically nonexistent when it comes to determining the weight limits of a Unistrut channel, but the Unistrut Midwest team has years of experience making the required calculations and designing Unistrut systems. Whether you want another set of eyes on your calculations or you want to hand the entire process over, our team is happy to help you determine the weight limit of the Unistrut channel for your desired application. To get started, gather the necessary information and then contact our team. 

These standard details are not site specific, and need to be reviewed by a qualified professional once actual loading and site conditions have been determined. Unistrut Midwest is not responsible for any misuse of any information or details presented.