J-Arm Heavy-Duty Universal 18-inch Mount

Key Specs

Mast Length: 18 inches (~450–470 mm) total run, providing sufficient offset clearance to keep antennas away from overhangs, trim, and wall surfaces.
Outer Diameter (O.D.): Typically, 1.66 in (42 mm) or 2.0 in (50.8 mm), matching the clamp collars and U-bolt spacing of standard outdoor CPE radios and antenna brackets.
Material & Finish: Heavy-gauge galvanized carbon steel (base thickness typically 1.6 mm / 16-gauge; pipe wall ~1.2 mm to 1.5 mm / 0.060 in) with hot-dip galvanization or UV-stabilized powder-coat/E-coat finishes to prevent corrosion in harsh environments.
Reversibility: Most universal baseplates can attach to either end of the pipe, allowing the installer to orient the short or long end upright depending on required eaves clearance.
Integrated Hardware: 2 × 3″ fully threaded lag screws, 4 × 2″ fully threaded lag screws, 2 × heavy-duty hose clamps, 1 × grounding screw

Direct Fastener Penetration (Wood / Framing):
Secured into structural wood (studs, rafters, rim joists) using 5/16" or 1/4" hot-dipped galvanized lag screws (typically 2" to 3" in length) paired with weatherproofing mastic or pitch pads.
Masonry & Brick Anchor Mount:
Attached to brick, concrete block, or poured masonry using 1/4" or 5/16" concrete wedge anchors, sleeve anchors, or Tapcons through the corner holes of the baseplate.
Pole / Mast-to-Mast Strapping:
Fastened to existing vertical or horizontal structural pipes, fence uprights, or utility poles using heavy-duty stainless steel hose clamps (worm-gear) or 1/2" steel strapping run through the baseplate’s stamped slots.
Strut Channel (Unistrut) Mount:
Bolted directly to P1000/P3000 Unistrut channel systems via channel nuts and 3/8" bolts for parapet and rooftop equipment racks.

Exterior Building Walls & Siding: Fastened directly through exterior cladding into the building frame/studs to clear gutters and maintain clear line-of-sight (LOS).
Roof Fascia & Eaves: Attached to fascia boards or rafter tails. The 18-inch curve extends the equipment outward and upward past gutters and roof edges without penetrating roof shingles.
Sloped or Flat Roofs: Installed directly on roof decking over rafters. The pivoting base compensates for pitch angles up to 45° to ensure the antenna mast remains plumb.
Chimneys & Parapets: Anchored into masonry parapets on commercial flat roofs or strapped around brick structures to achieve height above rooftop obstructions.
Towers, Poles, & Pipe Risers: Clamped onto tower leg sections, rooftop non-penetrating sled masts, or satellite standoffs to host secondary CPE hardware.

Substrate Target: Verify fasteners hit structural wood framing, solid masonry, or unistrut—never rely solely on vinyl siding, stucco, or OSB roof decking without underlying framing support.
Mast Plumb Alignment: Loosen the pitch pivot bolts, level the upright mast tube vertically using a torpedo level, and torque locking bolts to 10–12 ft-lbs to prevent slippage during high wind loads.
Waterproofing: Ensure each lag penetration through siding or roofing is sealed with butyl mastic tape or polyurethane roofing sealant beneath the baseplate.
Grounding: Terminate a minimum #10 AWG solid copper ground wire to the baseplate grounding screw and bond it to the structure’s central intersystem bonding termination (IBT).