Product Description

The Benchmade Full Immunity 290BK-1 is the FDE (Flat Dark Earth) aluminum variant of the Full Immunity automatic platform — the same M4 high-speed tool steel, black coating, 2.49-inch drop point, and push-button automatic mechanism as the 290BK-2, in a flat dark earth anodized aluminum handle for buyers who prefer an earth-tone carry profile over the green of the -2 variant.

The blade is M4, an ANSI high-speed tool steel with high vanadium and tungsten content. M4 is not stainless — it delivers extreme wear resistance and edge retention significantly exceeding standard stainless production steels, at the cost of requiring regular oiling and drying to prevent surface oxidation. The black coating reduces corrosion exposure between maintenance cycles. At 2.49 inches, the Full Immunity clears the sub-2.5-inch threshold used in some automatic knife statutes. FDE anodized 6061-T6 aluminum handle scales are rigid, corrosion-proof, and provide a neutral earth-tone carry aesthetic popular in duty, hunting, and outdoor carry environments.

Note: Automatic knives are subject to federal and state restrictions. Verify your local laws before purchasing. Ships same or next business day from Knifeworks in Columbia, Louisiana.

• Blade Steel: M4 high-speed tool steel, black coated — extreme wear resistance and edge retention; NOT stainless — requires regular oiling; will surface-oxidize without maintenance
• Blade: 2.49" drop point, plain edge — sub-2.5" automatic format; same blade spec as 290BK-2 green variant
• Handle: FDE (Flat Dark Earth) anodized 6061-T6 aluminum — earth-tone carry aesthetic; rigid, corrosion-proof; neutral color for duty, hunting, and outdoor carry
• 290BK-1 vs. 290BK-2: Same blade, steel, and mechanism — FDE aluminum (290BK-1) for earth-tone carry; green aluminum (290BK-2) for field carry
• Mechanism: Automatic (push-button) — confirm single-action vs. double-action at benchmade.com/products/290bk-1
• Dimensions: 5.55" overall, 3.06" closed, 2.20" edge length, 0.110" blade thickness, ~2.40 oz
• Blade Range: 1–2.49 in — sub-2.5" automatic format
• Warranty: Benchmade LifeSharp warranty — free lifetime sharpening, blade replacement, and mechanical repair