{"product_id":"3-8-in-x-4-1-2-in-carriage-bolt-kit-ceramic-black-25-pack","title":"3\/8 in x 4-1\/2 in Carriage Bolt Kit - Ceramic Black, 25 Pack","description":"\u003cp\u003eIn this review of the 3\/8 in x 4-1\/2 in carriage bolt kit the bottom line is simple: this is a heavy-duty exterior fastener pack for projects that need a neat semi-flush finish and better-than-galvanized corrosion resistance. The kit bundles 25 Grade 307A carriage bolts with USS flat washers and grade 2 hex nuts, all finished in a 5-layer ceramic black ruspert coat that the maker says gives roughly 2X the rust resistance of standard galvanized hardware. For anyone building decks, pergolas, gazebos or bolting down small structures, the consistent dimensions and the washer and nut matching make installation straightforward.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e5-layer ceramic ruspert coating:\u003c\/strong\u003e Provides a durable black finish and enhanced rust resistance for exterior exposure compared to basic galvanized options.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrade 307A carriage bolts:\u003c\/strong\u003e Offer reliable shear strength suitable for heavy duty outdoor framing and structural connections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComplete kit:\u003c\/strong\u003e Comes with 25 carriage bolts, 25 USS thick washers and 25 hex nuts so installers have matching hardware for each bolt without extra shopping trips.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSemi-flush flat head:\u003c\/strong\u003e The flat head design leaves a tidy, semi-flush appearance ideal for decks, pavilions and visible timber work.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConsistent sizing:\u003c\/strong\u003e The 3\/8 in diameter, 4-1\/2 in length and 0.813 in head diameter simplify planning and ensure a predictable fit with common lumber thicknesses.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWho It's For\u003c\/h2\u003e\u003cp\u003eThis kit is aimed at homeowners, contractors and hobby builders who need reliable carriage bolts for outdoor structures where appearance matters as much as function. The black ceramic finish looks intentional on exposed beams and pavilion rails while the included washers and nuts save time during installation.\u003c\/p\u003e\u003cp\u003eThose who need stainless fasteners for coastal installations with extreme salt exposure or who require higher-grade nuts than grade 2 should consider alternatives; this kit prioritizes value and a coated corrosion barrier rather than premium stainless alloys.\u003c\/p\u003e\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eSolid build and consistent dimensions make installation predictable and fast.\u003c\/li\u003e\n\u003cli\u003eThe 5-layer ceramic black ruspert coating gives a clean aesthetic and improved rust resistance over plain galvanized parts.\u003c\/li\u003e\n\u003cli\u003eComplete set of washers and nuts included provides good value for deck and pergola projects.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\u003cli\u003eSome customers report mixed results on long-term rust resistance compared with higher-end stainless options.\u003c\/li\u003e\u003c\/ul\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e3\/8 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003e4-1\/2 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHead diameter\u003c\/td\u003e\n\u003ctd\u003e0.813 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNut wrench size\u003c\/td\u003e\n\u003ctd\u003e9\/16 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWasher outside diameter\u003c\/td\u003e\n\u003ctd\u003e1 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKit contents\u003c\/td\u003e\n\u003ctd\u003e25 carriage bolts, 25 USS thick washers, 25 hex nuts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinish and grade\u003c\/td\u003e\n\u003ctd\u003e5-layer ceramic black ruspert coat; Grade 307A bolts; Grade 2 nuts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2\u003eOur Verdict\u003c\/h2\u003e\u003cp\u003eThe 3\/8 in x 4-1\/2 in carriage bolt kit represents a pragmatic choice for outdoor builders who want a tidy black finish and a corrosion-resistant upgrade over plain galvanized hardware. It is good value for decks, gazebos and similar projects where matching washers and nuts and consistent bolt sizing save time. For extreme coastal environments, consider stainless fasteners instead.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eAre the bolts fully threaded?\u003c\/strong\u003e\u003cbr\u003eThe kit includes standard carriage bolts with a smooth shank under the rounded head and threading at the end for the supplied hex nuts.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the black coating durable for exterior use?\u003c\/strong\u003e\u003cbr\u003eThe 5-layer ceramic ruspert coating is intended for exterior use and offers about 2X the rust resistance of galvanized parts, though stainless is still superior in very corrosive settings.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat tools are required for installation?\u003c\/strong\u003e\u003cbr\u003eInstallation typically requires a 9\/16 in wrench for the hex nuts plus appropriate drilling or countersinking tools for the 3\/8 in shank and a hammer to seat the carriage head if needed.\u003c\/p\u003e","brand":"Makers Bolt","offers":[{"title":"Default Title","offer_id":48660456046811,"sku":"B0DH75BMGG","price":39.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/61IzHh8DmOL._SL1500.jpg?v=1778637549","url":"https:\/\/gearmusthave.com\/products\/3-8-in-x-4-1-2-in-carriage-bolt-kit-ceramic-black-25-pack","provider":"GearMustHave","version":"1.0","type":"link"}