3/8" Thick 4.5" OD Round Aluminum Countersunk Pad | 3 Countersunk Holes + 1.5" Center Passthrough | Marine Grade 6061-T6
Part Number: 0156
4.5" Round Deck Pad with 1.5" Center Passthrough — Flush-Mount Hardware Mounting
Precision CNC-machined 6061-T6 aluminum round countersunk pad with three countersunk mounting holes and a 1.5" center passthrough for cable, hose, or wire routing. Designed for flush-mount fastening on fiberglass deck surfaces in saltwater marine environments. Three countersunk outer holes let flat-head screws sit flush with the pad surface, while the 1.5" center passthrough accommodates through-deck cable runs or antenna leads without drilling additional holes in the deck. Commonly used on top or through the side of a deck pedestal, as well as through the fiberglass skin of a hardtop or T-top.
| Material | Marine Grade 6061-T6 Aluminum |
| Outside Diameter | 4.5" (114 mm) |
| Thickness | 3/8" (0.375") |
| Mounting Holes | 3 countersunk (5/16" dia. for 1/4" fasteners) |
| Center | 1.5" passthrough (cable / hose / wire routing) |
| Shape | Round |
| Finish | Matte — tumbled, deburred, paint/powder coat ready |
| Weight | 0.5 lb |
Common Applications
T-tops, tuna towers, hard tops, radar arches, leaning posts, grab bars, bow rails, outrigger mounts, rod holders, antenna mounts — any fiberglass or aluminum deck surface requiring flush-mount hardware with a cable/hose routing path.
Frequently Asked Questions
What is the 1.5" center passthrough used for?
The 1.5" center hole lets you route cables, wiring, antenna leads, or small hoses through the pad for a cleaner finished install — no lines, wires, or hoses visible on the deck or exposed to the elements. It also serves as a weld vent during fabrication mounting.
What does "countersunk" mean for this pad?
Countersunk means the three outer mounting holes are chamfered so flat-head screws sit flush with the pad surface — no protruding screw heads that could snag lines or cause injury.
Can this pad be used on a fiberglass deck?
Yes — this pad is designed for fiberglass deck installations. The countersunk holes accommodate flat-head screws, and the pad distributes fastener loads over a wider surface area to prevent deck damage.
What size screws do I need?
The three countersunk holes are sized for 1/4" fasteners (5/16" hole diameter). Use 1/4"-20 stainless flat-head screws for best results in marine environments.
Is a backing plate required for installation?
For through-deck or pedestal-wall installations, Welding World recommends pairing this countersunk pad with a matching backing plate (grommet pad) on the opposite side. A backing plate spreads the clamping load, prevents the fiberglass from being crushed by the fastener heads, and provides galvanic isolation between stainless fasteners and the aluminum substrate.
- Local pickup available
- One Business Day Shipping
- Call us Mon.-Fri. 9:00 a.m. to 4:00 p.m. if in any doubt.
Due to this item's size and weight we can only ship it in an economical way via Less Than Truckload (LTL) consolidated land shipping, and only to the contiguous 48 States.
For shipping inquiries to AK, HI, PR, US-VI, and international shipping, please contact us first at sales@weldingworldinc.com.
All of the destinations above we can only serve as a Free Carrier (or FCA) modality, that requires the customer to contract and pay for their carrier service of choice. We can still ship the item, but only to a warehouse/receiving office within the 48-contiguous States.
In plain terms what this means is that if you want to ship your product to any non-contiguous US territory or internationally, you, the customer, has to provide us with the warehouse address of the carrier that serves your locality with an address within the contiguous 48-US States, as we do not ship overseas on our own.
