Unistrut dimensions are the foundation of every metal framing decision an engineer or contractor makes on an industrial project. The standard P1000 channel measures 1-5/8″ wide by 1-5/8″ deep, with a 7/8″ slot opening and a 12-gauge (0.109″) wall thickness. Those four numbers define which hardware fits, what loads the channel can carry, and whether a design will pass inspection in the field.
Knowing the correct unistrut dimensions across every series keeps a project on schedule and within budget. This guide covers the full Unistrut channel lineup, so every specifier works from verified numbers. Each section provides the key measurements needed to confirm specs before submitting a bill of materials.
Why Getting Channel Dimensions Right Matters Before You Order
Ordering a channel with the wrong slot width results in spring nuts being seated incorrectly, compromising the connection. A wall thickness at a lighter gauge than required will fall short of a span’s allowable load rating. Selecting a back-to-back channel when a single slot was specified doubles the material cost with no structural benefit.
Mis-specification in strut channel carries real consequences, including fitting incompatibilities, failed load calculations, code rejections, and costly rework. Engineers and contractors specifying Unistrut for industrial installations need verified numbers before submitting a bill of materials. The guide below covers every major channel series, so specifications are confirmed before the order is placed.
Unistrut Dimensions at a Glance: Channel Series Overview
The table below provides a side-by-side comparison of the key unistrut dimensions across all major series. Use it as a quick reference before diving into the series-specific sections below.
| Series | Width | Depth | Slot Opening | Standard Wall (Gauge) | Heavy Duty Wall (Gauge) |
| P1000 | 1-5/8″ | 1-5/8″ | 7/8″ | 12 ga (0.109″) | 10 ga (0.134″) |
| P3300 | 1-5/8″ | 3-1/4″ | 7/8″ | 12 ga (0.109″) | 10 ga (0.134″) |
| P5000 (Half Slot) | 1-5/8″ | 1-5/8″ | 7/16″ | 12 ga (0.109″) | N/A |
| P6000 / P7000 | 13/16″ | 13/16″ | 7/16″ | 14 ga (0.083″) | 12 ga (0.109″) |
| A1000 / A1200 | 1-1/4″ | 1-1/4″ | 9/16″ | 12 ga (0.109″) | N/A |
Each series section below provides full-dimensional detail and application context. Confirming the right series from this overview helps narrow the hardware selection faster.
For a practical guide to matching each Unistrut channel size to your load capacity and project requirements, see our Unistrut channel sizes comparison.
P1000 Series Channel Specifications
The P1000 is the industry standard, and the channel most engineers specify when a project sheet references Unistrut without further detail. Understanding these unistrut dimensions is the starting point for most industrial support installations. Its 1-5/8″ by 1-5/8″ profile serves as the benchmark for the entire metal framing channel system.
Key P1000 Dimensions:
- Width: 1-5/8″ (41.3 mm)
- Depth: 1-5/8″ (41.3 mm)
- Slot Opening: 7/8″ (22.2 mm)
- Standard Wall Thickness: 12 gauge / 0.109″
- Heavy Duty Wall Thickness: 10 gauge / 0.134″
The 12-gauge version handles the majority of industrial support applications, while the 10-gauge variant is selected when span lengths are longer or seismic code compliance requires increased section modulus. Spring nuts, channel nuts, and standard fittings are fully interchangeable across gauges within the P1000 series. Steinco stocks the full P1000 lineup, including solid back, slotted, double slot, pierced, and back-to-back configurations.
P3300 Series Channel Specifications
The P3300 is a back-to-back double-slot channel designed for applications requiring greater span or load capacity. Its double-depth profile gives it a significantly higher moment of inertia for demanding structural conditions. This series is a go-to selection for long-span horizontal runs and overhead mechanical support grids.
Key P3300 Dimensions:
- Width: 1-5/8″ (41.3 mm)
- Depth: 3-1/4″ (82.6 mm)
- Slot Opening: 7/8″ per face (22.2 mm)
- Standard Wall Thickness: 12 gauge / 0.109″
- Heavy Duty Wall Thickness: 10 gauge / 0.134″
The slot opening and hardware interface remain consistent with the P1000 series, allowing engineers to combine P3300 and P1000 within the same framing system. Fastener and fitting specs stay the same across both series in that configuration. Reviewing unistrut dimensions for both series before ordering confirms hardware compatibility across the full installation.
P5000 Half Slot Series Channel Specifications
The P5000 uses a half-slot profile with a narrower opening that changes how hardware interfaces with the channel. This design is selected for specific installation environments where a reduced slot is a functional advantage. Rooftop walkway systems and exposed exterior installations are the most common applications for this series.
Key P5000 Dimensions:
- Width: 1-5/8″ (41.3 mm)
- Depth: 1-5/8″ (41.3 mm)
- Slot Opening: 7/16″ (11.1 mm)
- Standard Wall Thickness: 12 gauge / 0.109″
A narrower slot reduces debris accumulation and limits water entry into the channel profile in outdoor settings. The P5500 is the back-to-back variant of this series for added rigidity. P5000 hardware requires half-slot channel nuts and compatible fittings sized for the 7/16″ slot opening.
P6000 and P7000 (13/16″) Series Specifications
The P6000 and P7000 series provide a compact 13/16″ profile designed for lighter-duty support work where a smaller footprint is required. This series is well-suited for interior applications with tight clearance constraints. Light conduit support, interior architectural framing, and low-load mechanical supports are the primary use cases.
Key P6000 and P7000 Dimensions:
- Width: 13/16″ (20.6 mm)
- Depth: 13/16″ (20.6 mm)
- Slot Opening: 7/16″ (11.1 mm)
- Standard Wall Thickness: 14 gauge / 0.083″
- Heavy Duty Wall Thickness: 12 gauge / 0.109″
The P7000 is the back-to-back version for applications that require additional rigidity within the same narrow-profile family. Always consult the Unistrut load table for the specific series and gauge in use to confirm load ratings. Applying P1000 series load tables to the P6000/P7000 will overstate the allowable load due to their thinner walls and smaller cross-sections.
A1000 and A1200 (1-1/4″) Series Channel Specifications
The A-series fills the dimensional gap between the 13/16″ P6000 and the 1-5/8″ P1000, making it the mid-range channel for projects that need a profile between the two. The 1-1/4″ by 1-1/4″ form factor is well-suited for commercial interior framing and moderate mechanical support work. Interior support framing, light mechanical supports in commercial buildings, and architectural framing are the most common applications.
Key A1000 and A1200 Dimensions:
- Width: 1-1/4″ (31.75 mm)
- Depth: 1-1/4″ (31.75 mm)
- Slot Opening: 9/16″ (14.3 mm)
- Standard Wall Thickness: 12 gauge / 0.109″
The A1200 is the back-to-back version for increased depth and higher load capacity. The 9/16″ slot opening requires A-series specific channel nuts and fittings, which are sized exclusively for this profile. Standard P1000 or P6000 hardware is sized for different slot openings and will seat incorrectly in the A-series channel.
How Wall Thickness and Gauge Affect Load Ratings
Gauge and wall thickness are the primary variables controlling how much load a given channel length can carry across a span. Selecting the correct gauge at the start of a project protects the structural integrity of the entire installation. Reviewing unistrut dimensions alongside the applicable load table before finalizing a design eliminates the need for field modifications during installation.
Standard Gauge vs. Heavy Duty in P1000:
- 12-gauge (standard): suited for most mechanical, electrical, and plumbing supports under typical span conditions
- 10-gauge (heavy duty): selected when loads are concentrated, spans are long, or seismic bracing requirements call for a higher section modulus
The outer profile dimensions and slot opening stay the same across standard and heavy-duty within the same series, so hardware remains interchangeable when upgrading gauge. Always pull the allowable load from Unistrut’s published load tables for the specific series, gauge, and span before finalizing a design. Confirming these values at the design stage eliminates the need for field modifications during installation.
Slot Opening Dimensions and Hardware Compatibility
The slot opening is the dimension that controls which nuts, fittings, and accessories function correctly in a given channel. Confirming slot compatibility as part of a full review of unistrut dimensions prevents unusable hardware from arriving on the job site. The table below maps each slot opening to its compatible channel series and hardware types.
| Slot Opening | Compatible Series | Compatible Hardware |
| 7/8″ | P1000, P2000, P3300, P4000 | Standard spring nuts, channel nuts, and all standard fittings |
| 7/16″ | P5000 (half slot), P6000, P7000 | Half slot channel nuts, 13/16″ series fittings |
| 9/16″ | A1000, A1200 | A-series channel nuts and fittings |
Spring nuts, channel nuts, and fittings are series-specific, and mixing components from different slot families on the same channel run can create loose connections that may work loose under vibration or load cycling. Verifying that slot engagement dimensions match is a required step before installation, whether sourcing hardware from a single supplier or multiple manufacturers. For federal, defense, and seismic applications, Steinco’s engineering team can confirm that the fitting selections are appropriate for the channel series and the specified load condition.
Order Unistrut Dimensions by Spec from Steinco
Steinco Industrial Solutions is a wholesale supplier of the complete Unistrut channel lineup, covering standard P1000 through heavy-duty 10-gauge, 13/16″ P6000, and A-series mid-range profiles. With over 30 years of experience in metal framing and industrial project management, Steinco’s team can verify unistrut dimensions against a project application, confirm hardware compatibility, and supply material cut to length, kitted, or ready for installation. Steinco holds a GSA MAS contract (47QSMS24D008D) active through 2029, which simplifies acquisition for government facility managers and prime contractors.
For large-scale seismic bracing installations or data center cable support grids, Steinco offers the channel series and gauges for immediate fulfillment. Contact Steinco directly at john@steincoindustrial.com or call 419.606.8512. The full channel section product pages are available at steincoindustrial.com/product-type/unistrut/.
Steinco also stocks the complete Flex-Strut product line for contractors sourcing cost-competitive metal framing channel wholesale.
Frequently Asked Questions
What is the standard Unistrut size?
The standard Unistrut channel is the P1000 series, which measures 1-5/8″ wide by 1-5/8″ deep with a 7/8″ slot opening and a 12-gauge (0.109″) wall thickness. These unistrut dimensions are the most widely specified in industrial, commercial, and government construction projects. The P1000 serves as the dimensional reference point for the entire Unistrut channel system.
What is the slot opening on the P1000 channel?
The P1000 has a 7/8″ (22.2 mm) slot opening. This dimension is consistent across the full P1000 family, including standard, heavy-duty, solid back, slotted, double slot, and pierced variants. All variants share the same 7/8″ slot, ensuring hardware interchangeability throughout the series.
What is the wall thickness of heavy-duty Unistrut?
Heavy-duty Unistrut P1000 channel has a 10-gauge wall thickness of 0.134″. The standard P1000 is 12 gauge at 0.109″. The heavier gauge increases the channel’s allowable load capacity and section modulus, making it the specified choice for longer spans, seismic bracing systems, and high-load applications.
What is the difference between P1000 and P3300?
Both series share the same 1-5/8″ width and 7/8″ slot opening, with the P3300 offering a depth of 3-1/4″ compared to the P1000’s 1-5/8″. The deeper P3300 profile is a back-to-back double-slot channel that provides significantly higher load capacity. It is used where longer spans or greater structural rigidity are required.
What is the difference between P1000 and P5000?
The P1000 and P5000 share the same 1-5/8″ by 1-5/8″ outer profile, with the P5000 featuring a half slot opening of 7/16″ in place of the P1000’s 7/8″. The narrower slot requires dedicated half-slot channel nuts and compatible fittings. The P5000 is commonly used for rooftop and exterior applications where a smaller slot opening is preferred.
Are P6000 and P1000 fittings interchangeable?
The P6000 has a 13/16″ profile with a 7/16″ slot opening, and the P1000 has a 1-5/8″ profile with a 7/8″ slot opening. The slot dimensions differ across the two series, so channel nuts and fittings are series-specific. Each series requires hardware matched to its own slot opening size.
What does the A1000 series channel measure?
The A1000 is a 1-1/4″ by 1-1/4″ channel with a 9/16″ slot opening and a 12-gauge (0.109″) wall thickness. It uses A-series specific channel nuts and fittings sized for the 9/16″ slot. Standard P1000 or P6000 hardware seats do not fit in the A-series channel due to differences in the slot openings.
How is the right Unistrut channel gauge selected?
The correct gauge is selected by starting with the applicable series and then applying the Unistrut load table for the span and load condition. Confirming unistrut dimensions against the load table ensures the standard 12-gauge option covers the support application, with the heavy-duty 10-gauge option selected when loads or spans push past the standard rating. For seismic applications, the governing code requirement determines the minimum acceptable wall thickness.
Can Unistrut channel series be mixed in the same framing system?
P1000 and P3300 are the most common combination, as they share the same 7/8″ slot and use the same hardware throughout. Mixing P1000 with P5000, P6000, or A-series channels requires separate hardware inventories for each slot family. Careful labeling on the job site keeps each hardware type matched to its correct channel series.
Does Steinco supply Unistrut channel by specific gauge and series?
Steinco stocks the full Unistrut channel lineup across the P1000, P3300, P5000, P6000/P7000, and A-series in standard and heavy-duty gauges. Available finishes include pre-galvanized, hot-dip galvanized, Perma-Green II, and stainless steel. Custom cutting, kitting, and pre-assembly are available, and Steinco’s team is ready to fulfill orders by spec for any project size.
