Bow eye (U-bolt) | A4 | M8230
Bow eye for boats and mooring in A4 / AISI 316 stainless steel is intended for use in demanding marine environments where high corrosion resistance and mechanical strength are required. The product is used as a fixed attachment point in a boat's bow for mooring lines, chains, or hooks. The design is adapted to absorb tensile forces from mooring and towing, as well as to distribute the load against the surface. It is suitable for installations where a long service life and reliable function under varying loads are essential. To obtain internal dimensions, you can use the center-to-center (cc) measurement on the drawing and subtract the thickness of the material (D).
APPLICATION AREA
The product is used in marine equipment, boats, docks, and trailer installations. It is intended for applications where a fixed and secure attachment point is required in the bow, for example for mooring, winching, or transporting a boat. The bow eye allows for secure connection to shackles, hooks, or straps and is dimensioned to handle tensile loads in the longitudinal direction. The choice of material provides resistance to salt water, moisture, and chemically aggressive environments.
TECHNICAL SPECIFICATIONS
Product type: Fitting
Product family: Bow eye
Material class: A4
Strength class: Not specified
Standard: Not specified
Diameter: Not specified
Execution: Eye with mounting plate or threaded attachment
Surface finish: Untreated
Environment: Marine
Delivery unit: Piece
FREQUENTLY ASKED QUESTIONS (FAQ)
What characterizes a bow eye in acid-proof stainless steel (A4 / AISI 316)?
A bow eye (bow eye bolt) is a heavy-duty attachment point specifically designed for marine loads and fixed mounting in the boat's hull:
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Secure anchoring in the bow: Serves as the boat's primary attachment point for mooring lines, locking chains, winch cables from boat trailers, or tow lines.
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Even force distribution: The construction passes through the hull and is secured on the inside with washers and nuts. This distributes high tensile forces over a larger hull area and prevents point loading in fiberglass or wood.
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Calculating internal dimensions: To quickly calculate the eye's free internal dimension, take the center-to-center measurement (cc) from the drawing and subtract the material thickness.
Why is acid-proof stainless steel A4 (AISI 316) the only correct choice in a marine environment?
Hull-mounted fittings are constantly exposed to harsh conditions where material failure can lead to serious incidents:
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Maximum protection against salt water: A4 steel (1.4401 / AISI 316) contains molybdenum, which provides superior protection against corrosion, crevice corrosion, and pitting in brackish water, harsh salt water, and humid marine environments.
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High mechanical strength: Withstands powerful and sudden pulling forces from waves, wind, or jerks in the mooring without deforming or suffering from fatigue cracks.
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Long service life without maintenance: Retains its strength and shiny surface for decades without the risk of rust stains on the hull.
How to correctly mount a bow eye for a watertight and strong installation?
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Drill and countersink holes: Drill the holes in the bow with exact precision based on the eye's cc-dimension. Lightly countersink the hole edges in the gelcoat/fiberglass to prevent stress cracks in the surface layer.
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Seal carefully: Apply plenty of marine sealant (e.g., polyurethane or MS polymer) around the threads and under the external contact surface to guarantee a completely watertight seal.
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Use reinforcement washers on the inside: Install heavy-duty A4 hull washers or a backing steel plate on the inside of the hull along with acid-proof locking nuts (A4) to provide maximum contact surface against the hull.