Best Carbon Steel Hex Bolts in 2026

Premium grade bolt kit to facilitate installation of exhaust headers

Rated at 170,000 PSI, which is considerably stronger than Grade 8 hardware

Bolts are 3/8" in diameter and have a 1.000 under head length; 16 pieces

Mighty Grip: these bolt screws feature deep wood screw coarse threads for superior holding and prevent stripping in the material; Can be applied in even severe environment. Often using with washer which distribute the pressure of the head evenly so that to prevent pull through.

Standard and Various Sizes: the kit includes 5 different most common used sizes: 5/16 x 3-1/2", 5/16 x 1-1/2", 5/16 x 2", 5/16 x 2-1/2", 5/16 x 3"; Diameter are all 5/16"; Thread Type are all Coarse (standard); Quantity: 56 pieces screws and washers in total (28 sets)

Premiun Material: Heavy duty screw bolts are made from 18-8 (304) stainless steel and coated with black oxide, which is certified, good look, strength and corrosion resistant.

Material : High quality alloy steel class 10.9, provides great strength and corrosion resistant.

Screw Type : M6 metric flanged bolts

Specification : Full thread, Pitch: 1.0mm. Screw Length : 16mm (Excluding Head). Diameter of head: 13mm. Diameter of hex washer: 18mm. Height of head: 8.1mm.

Made from carbon steel

8mm-1.25 x 25mm

Compact hex head and flange ideal for space is tight

Flange bolts are fasteners with a hexagonal head for use with a wrench or a socket drive. Sometimes called Frame bolts, flange bolts are different from standard bolts as they are designed with a circular flange / skirt under the head that functions as a built-in washer, distributing force evenly across the surface to which it will be fastened. The flange also helps compensate for excess space in large or misaligned holes yeilding increased resistance to rotational loosening.

Made of Class 10.9 tempered medium carbon steel similar to US Grade 8 and possess strong wear resistance as well as high tensile strength. Mostly used for automotive and fastening applications such as steering and suspension parts, cylinder, and flywheels, and also for high strength mechanical applications and forged parts. The Yellow Zinc finish, aside from the golden aesthetic, provides a marginally better protection from rust and corrosion against water contact than clear zinc or black oxide.

M8 - M12 Diameter JIS (Japanese Industrial Standard) Flange bolts </b> have smaller head sizes than ISO and ANSI type bolts and are commonly used for truck, car, ATV, snowmobile, and motorcycle frames, exhaust, and for securing the outer casing protecting the engine and transmission. This type of bolt is suitable for any use that requires mounting surface protection.

Flange bolts are fully-threaded fasteners with a hexagonal head for use with a wrench or a socket drive. Sometimes called Frame bolts, flange bolts are different from standard bolts as they are designed with a circular flange or a skirt under the head that functions as a built-in washer and distributes the force evenly across the surface to which it will be fastened. The flange helps compensate for excess space in large or misaligned holes yielding increased resistance to rotational loosening.

Made of Class 10.9 tempered medium carbon steel similar to US Grade 8 and possess strong wear resistance as well as high tensile strength. Mostly used for automotive and fastening applications such as steering and suspension parts, cylinder, and flywheels, and also for high strength mechanical applications and forged parts. The Zinc finish provides a marginally better protection from rust and corrosion against water contact than clear zinc or black oxide.

<b> M8 - M12 Diameter JIS (Japanese Industrial Standard) Flange bolts </b> have smaller head sizes than ISO and ANSI type bolts and are commonly used for truck, car, ATV, snowmobile, and motorcycle frames, exhaust, and for securing the outer casing protecting the engine and transmission. This type of bolt is suitable for any use that requires mounting surface protection.