A round tenon on your pole or arm points you toward a slip-fitter mount, while a documented flat wall or structural surface points toward a trunnion mount. Understanding the slip-fitter vs trunnion mount flood light difference ensures you specify the right hardware the first time. Neither path is final until the exact fixture receiver, mount geometry, and complete-assembly load documentation actually line up.
When any of those details is still unresolved, hold the order and verify before you buy.
Key Takeaways
- A compatible round tenon is the entry condition for a slip-fitter; a documented flat surface is the entry condition for a trunnion.
- The two mounts use different physical connections: a slip-fitter slides over a vertical tenon, while a trunnion is a two-point, pivoting bracket built for surface mounting.
- Aiming range depends on the exact fixture and mount configuration, not the mount category alone.
- EPA and wind-load approval must cover the whole assembly, fixture, mount, accessories, support, and orientation, together against the project's wind basis.
- Confirm the receiver, dimensions, fasteners, aiming path, and load documentation before ordering, and hold the purchase if any of them conflicts with what is on site.
Which Mount Fits Your Commercial Floodlight Installation?
The right starting point is your existing support interface, not the mount name on a spec sheet. A compatible round tenon makes a slip-fitter the relevant path; a documented flat surface makes a trunnion the relevant path. If the receiver, dimensions, or load documentation are still unclear, the correct answer is to verify first rather than force a choice.
| Mount path | Eligible support condition | Order decision |
|---|---|---|
| Slip-fitter | Round tenon confirmed, fixture receiver and tenon dimensions match | Proceed once documented |
| Trunnion | Flat surface confirmed, bracket bolt pattern and structural support documented | Proceed once documented |
| Verify first | Tenon or surface type, receiver, or load basis unresolved | Hold order, request review |
Browsing the mount adapter collection can help you compare adapter styles once you know which support interface you actually have on site.
How Slip-Fitter and Trunnion Attachments Differ
The two mounts transfer load to your support in different ways, which changes what you need to measure before buying. A slip-fitter is built to slide over a vertical, round tenon on a pole or arm, so the fixture's tenon-side opening has to match that tenon's diameter and height. A trunnion, by contrast, is a U-shaped bracket that attaches at two points on a flat surface and lets the fixture pivot on a single axis, according to the slip-fitter and trunnion attachment guide.
That difference decides which measurements matter. For a slip-fitter, you need the tenon diameter, wall thickness, and fixture receiver opening. For a trunnion, you need the bolt pattern, bracket footprint, and the flat surface's structural capacity. Neither category description alone proves that a specific product fits your fixture; the receiver, dimensions, and fastener access on your current drawing still have to match what's physically on site.
How Aiming Adjustment Changes the Choice
Aiming needs should be defined by the direction and orientation your project requires, not by which mount sounds more adjustable. In the reviewed configuration, the slip-fitter mount offers 180 degrees of vertical tilt, which is a useful example of what a tenon-mounted fixture can achieve, but that figure applies to that configuration only, not to every slip-fitter on the market, per the reviewed 180-degree slip-fitter tilt example.
A trunnion pivots along a single axis in the reviewed description, so its practical range and how it locks in place depend on the specific bracket and fixture pairing. If your project needs a particular beam angle, confirm the allowable tilt, locking hardware, and orientation limits in the current fixture instructions before you commit to either mount type. Skipping that step is how a fixture ends up aimed correctly on paper but wrong once it's actually installed.
How to Verify EPA and Wind-Load Requirements
Do not approve a mount from its category name or a generic EPA reference alone. Wind load has to be evaluated for the complete supported assembly, meaning the fixture, the mount, any accessories, the support structure, and the fixture's final orientation, checked together against the project's wind basis.
Pull current documentation for each of those pieces before you finalize the order. If the fixture, mount, and support were specified separately, or if any of the load paperwork is missing or conflicts with the physical installation, that is a documentation gap, not a minor formality. Do not proceed with mount approval or installation planning until the complete fixture-mount-accessory-support assembly can be reconciled with the project's required wind-load documentation. A mount that looks correct in a catalog description is not the same thing as an engineered, project-specific load approval.
Pre-Buying Checklist for a Commercial Floodlight Mount
Turn the comparison above into a pass or hold decision using these six checks before you release the order.
- Support surface and structure. Confirm whether you have a round tenon, wall, facade, or another documented structural surface, and confirm it can carry the fixture's weight and wind load.
- Fixture receiver and product variant. Record the exact fixture model and mounting variant, since receiver geometry can differ between otherwise similar fixtures.
- Tenon dimensions, bolt pattern, or bracket geometry. Match the tenon diameter and height, or the trunnion's bolt pattern and bracket footprint, against your current product drawing, following the fixture receiver and fastener checks used for tenon and bracket sizing.
- Required aiming direction. Confirm the fixture's documented tilt range and locking method against the beam direction your project actually needs.
- Fastener access and support details. Verify that the fasteners specified for the mount are accessible on site and match the support material.
- Load documentation and project wind basis. Confirm that current load documentation covers the complete fixture-mount-accessory-support assembly and matches your project's wind requirements.
If any single check fails or the documentation conflicts with what's on site, hold the order and request a technical compatibility review instead of substituting a nominally similar mount.
FAQs
How do I evaluate reusing an existing mount with a replacement fixture?
Do not assume mechanical fit simply because the mounting style is identical. A replacement fixture may feature a different receiver bore, bolt pattern spacing, or fastener size than the original unit. Before mounting, verify the replacement fixture receiver against the existing mount dimensions, check the intended tilt range, and confirm that the complete assembly load rating satisfies your project's wind basis.
What information should I provide when the mount fit is unclear?
Assemble the exact fixture model and variant, photos or drawings of the receiver and support, tenon dimensions or bolt pattern, fastener details, the intended mounting orientation, any accessories, and your project's wind-load requirements. With that packet in hand, the practical next step is to request a compatibility review rather than order based on the mount category name alone. Our team can review that documentation before you commit to a purchase.
Can a trunnion bracket be installed on a round pole or curved surface?
Not without a documented transition plate or curved-surface adapter engineered for that specific pole diameter. Standard trunnion brackets require continuous contact against a flat plane to distribute mechanical tension evenly across both mounting points. Fastening a flat trunnion bracket directly across a curved face distorts the bracket arms, compromises fastener seating, and invalidates complete-assembly wind-load documentation.
