304 Stainless Steel

The Whitecap shear pins in the S-1000 series (including the ones you listed: S-1009, S-1008, S-1007, S-1005, S-1004, S-1003) are all very similar in design and purpose. They are marine-grade shear pins (also called breakaway or sacrificial pins) made from 304 stainless steel for corrosion resistance in freshwater and saltwater environments. They are sold individually (or sometimes in packs like 4-packs at retailers such as West Marine), and their primary function is to act as a deliberate weak point in mechanical systems — they shear/break under excessive force or overload to protect more expensive or critical components from damage (e.g., in propellers, outboard motor shear pins, trolling motor mounts, or other boat hardware where impact or overload could occur).

Key Similarities Across All These SKUs

• Material: 304 stainless steel (durable, rust-resistant, suitable for marine use).
• Design: Plain, straight cylindrical shear pins (no threads, no detents, no handles/lanyards — unlike the quick-release detent pin from your previous query). They are simple, solid pins meant to be inserted through aligned holes and secured (often with a cotter pin, clip, or nut on the end, depending on the application).
• Primary Function: Sacrificial/shear protection — they break at a predetermined shear strength to prevent damage to engines, mounts, or assemblies.
• For Use In: Explicitly rated for both freshwater and saltwater.
• Quantity: Individual (though bulk/packs available elsewhere).
• No major functional differences beyond dimensions — they don't have varying head styles, materials (all 304SS), coatings, or mechanisms. Whitecap doesn't indicate different shear strengths, grades, or tolerances per SKU in their listings.

Differences: Primarily Size Only

The only consistent variation across Whitecap's product pages and retailer descriptions (e.g., whitecapmarineproducts.com, West Marine, Opentip) is the diameter × length:

• S-1003: 5/32" diameter × 1" length
• S-1004: 5/32" diameter × 1-3/16" length
• S-1005: 1/8" diameter × 1" length
• S-1007: 3/16" diameter × 1-3/16" (or sometimes listed as 1-1/16" in packs, but core listings match your 1-3/16")
• S-1008: 3/16" diameter × 1-5/16" length
• S-1009: 3/16" diameter × 1-3/8" length
• Diameter affects shear strength (thicker = higher force needed to break) and fit in holes.
• Length determines how much material engages or protrudes (for grip/thickness of the assembly it's pinning).

These sizes allow matching to specific equipment requirements (e.g., smaller diameters for lighter-duty applications like small trolling motors; larger for outboards or heavier loads). Shear strength scales roughly with cross-sectional area (diameter), but Whitecap doesn't publish exact shear ratings per model — it's assumed to be proportional to size, and users select based on OEM recommendations for their motor or mount.

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