{"product_id":"gpt-airsoft-hook-castle-nut-wrench","title":"GPT Airsoft Hook Castle Nut Wrench","description":"\u003cdiv style=\"background:#edfaf1;border-left:4px solid #27ae60;padding:12px 16px;border-radius:0 6px 6px 0;margin:0 0 16px;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#1a6b3a;\"\u003eGPT Airsoft Hook Castle Nut Wrench — \u003c\/strong\u003e Forged chrome vanadium steel castle nut hook wrench, manganese phosphate finished. Made for AR\/M4\/HK416 buffer extension nuts (including HK416 round-hole nuts) and works on the DD MK18 barrel nut too.\n\u003c\/div\u003e\n\u003cp\u003eCastle nut work comes up every time you change a buffer tube, swap a stock, or service the rear wiring on an M4-pattern AEG or GBBR. Most generic spanners either don't fit the castle-nut notches properly or slip off under load. A purpose-made hook wrench like this one engages two notches at once, locks in cleanly, and won't round off the nut when you put real torque through it.\u003c\/p\u003e\n\u003cp\u003eForged chrome vanadium steel is the material that matters here — significantly stronger than stamped or pressed-steel wrenches, and the forging process produces a tighter grain structure that won't deform under repeated use. The manganese phosphate surface finish is the same protective treatment used on real-steel firearm parts: corrosion resistant, oil-retaining, and tough enough that it doesn't flake off even if the wrench gets thrown in a tool bag with everything else.\u003c\/p\u003e\n\u003cp\u003eWorks on AR-15\/M4 buffer extension nuts (the standard castle nut found behind nearly every M4-pattern stock), HK416-pattern round-hole nuts, and the Daniel Defense MK18 barrel nut. If you're servicing your own rifles or working on builds, this is one of those tools you need exactly once per build but absolutely have to have when you do.\u003c\/p\u003e\n\u003ch2 style=\"font-size:16px;color:#1B3A6B;margin:18px 0 8px;\"\u003eSpecifications\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;font-size:13px;margin:0 0 18px;\"\u003e\n  \u003ctr style=\"background:#1B3A6B;color:#fff;\"\u003e\n    \u003cth style=\"padding:7px 12px;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n    \u003cth style=\"padding:7px 12px;text-align:left;\"\u003eDetail\u003c\/th\u003e\n  \u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eMaterial\u003c\/td\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eForged chrome vanadium steel (CRV)\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eSurface Finish\u003c\/td\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eManganese phosphate\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eFits\u003c\/td\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eAR \/ M4 \/ HK416 buffer extension nuts\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eAlso Fits\u003c\/td\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eHK416 round-hole nut, DD MK18 barrel nut\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eApplication\u003c\/td\u003e\n    \u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eBuffer tube installation, stock swaps, MK18 barrel work\u003c\/td\u003e\n  \u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cdiv style=\"background:#1B3A6B;color:#fff;padding:12px 16px;border-radius:6px;margin:18px 0 0;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#fff;\"\u003e💡 Titan Forge Airsoft tip:\u003c\/strong\u003e When tightening a castle nut, finger-tight first to make sure the threads are clean, then torque it down with the wrench. Forcing a cross-threaded castle nut with this wrench will damage both the nut and the buffer tube threads — and those threads are aluminium on most M4 platforms, which won't recover.\n\u003c\/div\u003e","brand":"Gun Power Tools","offers":[{"title":"Default Title","offer_id":55559287144824,"sku":"1166392725","price":12.95,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0562\/8097\/3450\/files\/GPTAirsoftHookCastleNutWrench-1.png?v=1778779425","url":"https:\/\/www.titanforgeairsoft.com\/products\/gpt-airsoft-hook-castle-nut-wrench","provider":"Titan Forge Airsoft","version":"1.0","type":"link"}