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Marine Fasteners RP-81 5/16-18 x 2in 18-8 Stainless Steel Hex Cap Screw 25-Pack

Manufacturer

Marine Fasteners

<h3>About Marine Fasteners</h3><p>For decades, <strong>Marine Fasteners</strong> has built its reputation on a straightforward promise: stock quality hardware, keep plenty of it on the shelf, and back every order with knowledgeable customer service. Recognized as America's leading supplier of marine, solar, and industrial fasteners, the company has followed this philosophy since 1975. That long track record of reliability has made Marine Fasteners a go-to source for boatbuilders, solar installers, contractors, and industrial maintenance crews alike.</p><h3>A Specialist in Corrosion-Resistant Hardware</h3><p>What sets Marine Fasteners apart is its deep focus on materials engineered to survive punishing environments. The brand carries a full line of 304 and 316 stainless steel bolts, socket products, screws, nuts, washers, pins, and specialty fasteners, and also offers multiple secondary processes along with a proprietary line of chrome-plated inventory. This breadth of material options means customers can match the exact alloy grade to their application — whether that's a saltwater-exposed through-bolt on a boat deck or a structural anchor in a solar panel array.</p><p>With more than 35 years of thriving in demanding conditions and a team boasting over 700 years of combined experience, Marine Fasteners understands the nuances of stainless steel fastener requirements across a wide range of industries. That institutional knowledge translates directly into better product selection guidance and fewer costly specification mistakes.</p><h3>A Comprehensive Catalog Under One Roof</h3><p>The Marine Fasteners catalog spans an impressive range of hardware categories. Core product lines include bolts, nuts, screws and threaded products, washers, U-bolts, anchors, socket products, cable ties, rivets, rods and studs, snaps, hose cable and cushion clamps, clips and retaining rings, drill bits, pins, driver bits, hex keys, and kits and assortments. This single-source approach simplifies procurement for professionals who need a wide variety of fastener types without juggling multiple suppliers.</p><p>The brand also distributes specialty sub-lines to meet niche demands. The <strong>Fasco Fastener</strong> division — a proprietary Marine Fasteners line — covers packaged cable ties, packaged chrome fasteners, packaged cushion clamps, and packaged hose clamps, making it easy for retailers and distributors to merchandise pre-packaged hardware. For self-drilling applications, Marine Fasteners stocks the <strong>Elco</strong> product line, which includes 18-8 and bi-metal steel self-drilling screws in a range of diameters and lengths with Stalgard finish for superior corrosion protection.</p><h3>Materials Built for the Elements</h3><p>Choosing the right fastener material is critical in marine and outdoor environments. Stainless steel grades such as AISI 304 and AISI 316 are common choices due to their strength and corrosion resistance, with 316 offering superior resistance to chlorides found in seawater and deck hardware exposed to spray. Marine Fasteners stocks both grades across its full product range, along with silicon bronze, brass, nylon, aluminum, and hot-dip galvanized options to suit every substrate and exposure level.</p><p>Whether you're sourcing a few hundred bolts for a dock repair or placing a large industrial order for a manufacturing facility, Marine Fasteners has the inventory depth, material expertise, and product variety to get the job done right.</p>

Part Number

RP-81
05/31/2036 8:54 PM
Sale Price

$15.34

In Stock (10+)

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Usually delivered within 2 days

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Product Details

The Marine Fasteners RP-81 is a 5/16-18 x 2-inch hex head cap screw manufactured from 18-8 stainless steel, sold in a convenient 25-piece pack. Engineered for corrosion resistance in demanding marine, coastal, and outdoor environments, these fasteners deliver reliable clamping strength wherever exposure to moisture, salt air, or the elements is a concern.

Hex cap screws differ from standard hex bolts in two important ways: they feature a machined washer bearing surface on the underside of the head and a chamfered thread end, and they are held to tighter dimensional tolerances per ASME B18.2.1. This makes them the preferred choice for precision assemblies and applications where joint integrity matters.

Key Features:

  • Material: 18-8 (304) stainless steel — excellent resistance to rust, corrosion, and oxidation
  • Size: 5/16-18 UNC (Unified National Coarse) x 2 inches
  • Head Style: Hex head cap screw with machined bearing surface
  • Drive: 1/2-inch hex wrench or socket
  • Thread: 18 threads per inch, coarse pitch
  • Quantity: 25 pieces per pack
  • Standard: Dimensionally conforming to ASME B18.2.1

18-8 stainless steel provides an excellent balance of strength and corrosion resistance, making these screws well-suited for boat building, dock hardware, marine equipment assembly, and any outdoor fastening application where longevity and appearance are important. The coarse 5/16-18 thread engages quickly and is highly resistant to cross-threading, making installation straightforward in the field.

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