Answers to Common Product and Technical Questions
Find answers about MCL Hangers products, selection, installation planning, ordering, technical resources, distributor opportunities, and support.
ABOUT MCL HANGERS
General Questions About MCL Hangers
Learn what MCL Hangers makes, where the system is used, and the role the product plays within a project.
What are MCL Hangers used for?
MCL Hangers are designed to hang mechanical, electrical, plumbing, fire protection, gas piping, and HVAC systems concentrically from open web steel joists (top or bottom chord). They place the hanger and threaded rod directly between the joist chord angles.
What are the key product models and their differences?
M1 is designed for use on both top and bottom joist chords with a 1” chord gap, as well as strut bars. M2 features an elongated shank for cold-formed chords with either 1” or 1-1/8” gaps (not for use on strut bars). M3 is designed specifically for use with all-thread rod, standard bolts, or carriage bolts on Unistrut channels.
What rod sizes and gap dimensions are compatible?
MCL Hangers are designed to work on open web steel joists with chord gap widths ranging from 0.85” to 1.25”. They accommodate all-thread rod sizes of 1/4”, 3/8”, and 1/2” in any desired length.
Are MCL Hangers safety certified for fire protection and load capacity?
Yes. MCL Hangers for 3/8” and 1/2” rods meet UL standards for safety under UL 203, ULC/ORD C203, and NFPA-13 standards for pipe hanger equipment in fire protection service. They are UL-listed to support up to 4,050 lbs per hanger.
How do MCL Hangers help save on labor time and costs?
MCL Hangers can be pre-assembled with all-thread rods on the ground before being placed on the joists, speeding up overall installation. Their low-profile design allows for rapid attachment within 6” of panel points without requiring field welding or drilling.
Where are MCL Hangers manufactured, and how can they be ordered?
MCL Hangers are manufactured in the United States. You can order directly through MCL Hangers by submitting an online quote/order form, sending an email, or calling us to find a local distributor.
PRODUCT SELECTION
Choosing the Right Hanger and Hardware
Use the actual field condition and current technical documentation to select the appropriate hanger and hardware.
How do the M1, M2, and M3 models compare against each other?
The primary difference comes down to the mounting surface and joist construction. The M1 is the standard workhorse designed for narrow gap angle irons and standard strut bars, whereas the M2 features an elongated shank to drop deeper into the wider gaps typical of cold-formed steel joists. The M3 differs by being specifically engineered for Unistrut systems and versatile bolt connections — though unlike the M1 and M3, the M2 should never be used on strut bars.
When should I choose the M2 over the M1 for joist applications?
While the M1 is the go-to standard for hot-rolled steel joists, you should select the M2 when working on cold-formed (cold-rolled) steel joists. Cold-formed chords have a deeper profile, and the M2’s elongated shank ensures the hanger drops far enough down into the chord gap to achieve a secure, full concentric engagement.
Which MCL Hanger should I select if I am attaching to strut or Unistrut channels?
If you are mounting directly to standard strut bars or Unistrut framing, choose either the M1 or the M3. Both models are compatible with strut systems. Do not use the M2 on strut bars, as its elongated shank is engineered specifically for deep joist chord gaps rather than shallow strut channels.
How do I select the right thread size for my application?
MCL Hangers are available in 1/4”, 3/8”, and 1/2” thread sizes. 1/4” is best for lighter mechanical, electrical, or small conduit runs. 3/8” and 1/2” options are ieal for heavier installations such as fire sprinkler piping, HVAC ductwork, and heavy plumbing runs. Note: Only the 3/8” and 1/2” sizes are UL-Listed under UL 203 for fire protection service.
Should I order individual hangers or complete hanger sets?
Order individual hangers if you already have custom-length all-thread rod, washers, and hex nuts on site. Order complete sets (which include the hanger, a 5″ all-thread rod, heavy-duty washer, and hex nuts) for standard top/bottom chord installations where a complete out-of-the-box hanging kit speeds up field assembly.
M1 Hanger
Questions About the M1 Steel Joist Hanger
What types of joists and surfaces are compatible with the M1?
The M1 is designed for standard hot-rolled steel joist chords (both top and bottom) with chord gap widths between 0.85” and 1.0875”. It is also fully compatible for mounting directly onto standard strut bars.
Can the M1 be installed on both top and bottom joist chords
Yes. The low-profile geometry of the M1 allows it to sit flush and load concentrically directly between the angle irons on either the top chord or the bottom chord of open web steel joists.
Is the M1 hanger UL-listed for fire sprinkler installations?
Yes, provided you select the 3/8” or 1/2” thread size. The M1 in these sizes meets UL 203, ULC/ORD C203, and NFPA-13 requirements for fire protection systems. The 1/4” size is intended for lighter MEP trades and is not UL-listed for fire piping.
M2 Hanger
Questions About the M2 Steel Joist Hanger
Why do cold-formed joists require the M2 instead of the M1?
Cold-formed (cold-rolled) steel joist chords feature deeper internal return lips and wider gaps (0.96” to 1.20”). The M2 features an elongated shank engineered specifically to drop far enough down into those deeper profiles to ensure full, safe engagement.
Can I use the M2 hanger on standard strut bars or Unistrut?
No. You should never use the M2 on strut bars. Because of its elongated shank, the M2 will not sit flush or lock securely into shallow strut channels. Use the M1 or M3 for strut applications instead.
Does the M2 have the same weight load capacity as the M1?
Yes. When installed with 3/8” or 1/2” all-thread rod, the M2 carries the exact same UL-listed load capacity of up to 4,050 lbs per hanger as the M1.
M3 Hanger
Questions About the M3 Steel Joist Hanger
What hardware can I use with the M3 hanger inside Unistrut channels?
The M3 is engineered specifically for Unistrut framing and provides maximum fastener flexibility. It accepts standard all-thread rod, standard hex head bolts, and carriage bolts, allowing you to secure channel runs without relying on traditional spring-channel nuts.
How does the M3 differ from using standard Unistrut channel nuts?
Standard channel nuts rely on thread friction inside the channel track, whereas the M3 acts as a structural bracket that bridges across the channel, distributing mechanical loads more evenly and preventing slippage along the strut.
Is the M3 compatible with standard joist chords like the M1?
Yes. While the M3 excels in Unistrut framing, its top-plate geometry and chord clearance allow it to mount across standard open web steel joist gaps (0.85” to 1.0875”) using standard bolts or threaded rod.