Bolts

Compared with other fastening systems, nuts and bolts have the advantage that they can be disassembled as needed, while other fasteners such as rivets are designed for permanent installation. Bolts are often used with nuts and washers, where the washer provides an increase in surface area over which the attachment force is applied. There are a variety of different types of nuts that can be used with a bolt, the most common one being hex nuts. Other nut types include:

• Prevailing Torque Locknuts
• Nylon Insert Locknuts
• K-Lock Locknuts
• Slotted Hex (Castle) Nuts
• Flange Nuts
• Cap Nuts
• Coupling Nuts
• Wing Nuts)
• Square Nuts
• Panel Nuts
• Surface Mount Nuts
• Rivet Nuts

Bolt Grades

Bolts and nuts are available in a variety of different material options, depending on the intended application. Bolts, screws, and other types of fastener products are graded when their operation must meet a certain performance. Ungraded hardware is used where their performance is not critical and a failure would not lead to danger or injury. The grade establishes the minimum acceptable standard of mechanical properties or performance that the fastener must meet. Higher grades imply bolts with greater mechanical strength characteristics and higher levels of traceability of the materials used in m anufacturing as well as control and inspection of the quality of the fastener and its dimensions.

Bolt Grade Markings

Grade identification marks are created and appear on the head of the bolt and are used to designate their grade. For commonly used ISO, DIN, ASTM and SAE steel grades, there are grade identification tables that designate these markings and specify the minimum acceptable values of proof, tensile, and yield strength that are required to meet the particular grade of bolt. To meet the grade requirements, specific materials, processing and heat treatment are used for the finished product.

AN Bolts

AN - an acronym for “Army and Navy” and sometimes "Air Force and Navy", AN bolts are characterized by their specification and quality control. AN Bolts are industrial aircraft bolts and are manufactured according to Air Force-Navy specs. They are manufactured from cadmium or zinc plated corrosion resistant steel, unplated corrosion-resistant steel, and anodized aluminum alloys. Length, grip, diameter, drilled head, and shank are the different variables within an AN bolt part number. They can be used for both ductile and/or shear applications and are coded to a specific standard. To the untrained eye, AN bolts look like ordinary bolts. They feature a partially threaded shank with a head. Like with most other bolts, they are designed to secure multiple parts together. AN bolts can be inserted through the threaded holes of two or more parts, after which they will hold the parts together. AN bolts are distinguished from ordinary bolts by their specification and rigorous quality control. The AN specification is the predecessor to the Military Specifications (MS or Mil-Spec) which is currently used by the US military. Current AN Bolts are used extensively in aerospace and aviation for their measurable reliability. AN Bolts are also used in many fastening applications where their form, function and reliability are desired. AN Bolts are typically only used in applications where the additional cost of the specification, quality and reliability is justified.

NAS Bolts

NAS bolts comply with the National Aerospace Standard and are commonly used for high technology systems. NAS bolts are necessary for high strength applications and consist of a fine-threaded, dimple headed hex bolt. Material markings for NAS bolts are the same as AN bolts, except they may be either raised or recessed.

NASM Bolts

NASM bolts include precision fasteners that previously fell under MIL-spec requirements and were converted to NASM specifications by the Aerospace Industries Association. The “MS” portion of the part number indicates the specification it meets (ex.MS51957).

MS Bolts

MS bolts have been tested and certified to Military Standard for use in high-performance applications. Military Standard bolts are available with either coarse or fine threads and are made from a range of materials with different finishes.

B1821, MS90725 and MS90726 Bolts

Alloy Hex Cap Screws offered in Grade 5 (MS90725 and MS90726); Grade 8 alloy steel or Grade BD alloy steel with zinc coating. Several sizes are available meeting specifications B1821 or Grade 5 MS90725 and MS90726.

ASME B18.2.1.BH Series Bolts

B1821 Bolts are hex cap screws with either a UNC-2A Coarse Thread or a UNF-2A Fine Thread. Equivalent to Grade 8, Material is Alloy Steel to ASTM A354BD and finish is Zinc Yellow Plating to ASTM B633.

B1821 Fine Thread UNF-2A Bolts

B1821 fine thread bolts replace the MS90726 series

B1821 Coarse Thread UNC-2A Bolts

B1821 course thread bolts replace the MS90727 series

What is Federal Supply Class 5306?

FSC 5306 is the Federal Supply Class(formally known as NATO Supply Classification Class NSC 5306) in the USA for supply items codified in the category of Bolts.

What is NATO Supply Classification Class 5306?

NSC 5306 is the NATO Supply Classification Class (also known as Federal Supply Class FSC 5306 in the USA) for supply items codified in the category of Bolts.

Which Federal Supply Group is FSC 5306 in?

FSC 5306 is in Federal Supply Group(FSG) 53 which contains .

Which NATO Supply Classification Group is NSC 5306 in?

NSC 5306 is in NATO Supply Classification Group(NSG) 53 which contains .

What is a Toggle Bolt? 275 Items

A Toggle Bolt (BOLT,TOGGLE) is an externally threaded fastener whose threaded portion is of one nominal diameter having a wing or wings mounted on the bolt head or on a trunnion nut. The wing or wings upset when the toggle bolt is inserted in a constricted passage in a hollow wall and when the bolt is tightened, the wing or wings assume a transverse or athwart position. It is used for securely holding fixtures or devices to hollow walls.

What is a Ring Bolt? 342 Items

A Ring Bolt (BOLT,RING) is a BOLT, EYE having a nonremovable ring assembled in the eye.

What is a Bolt Blank? 451 Items

A Bolt Blank is a cylindrical device having a head, eye or hook; similar to a BOLT, MACHINE; BOLT, EYE or BOLT, HOOK, and the like, but without threads, and normally intended for a subsequent threading operation.

What is a Machine Bolt? 91918 Items

A Machine Bolt (BOLT,MACHINE) is an externally threaded fastener designed for insertion through holes in assembled parts and normally intended to be tightened or released by torquing a nut. The threaded and unthreaded portions are both of one nominal diameter of 0.190 inch (5 mm) or larger. The head is not designed to be held or driven with an inserted driver or by the thumb and fingers. A locking feature may be incorporated in the design of the head or threads. Head dimensions and sizes of threaded and unthreaded portions shall conform to internationally recognized fastener standards. For items having a grip length portion machined to a tolerance of 0.0015 inch (0.038 mm) or less, BOLT, SHEAR. See also SCREW, CAP, HEXAGON HEAD and SCREW, MACHINE.

What is a Sliding Handle Bolt? 111 Items

A Sliding Handle Bolt (BOLT,SLIDING HANDLE) is an externally threaded fastener whose threaded and unthreaded portions are of one nominal diameter, No. 10 (0.190 IN.) (5 mm) or larger. The head is usually spherical in shape, all of which is of greater diameter than the threaded and unthreaded portions, and has a nonremovable sliding handle used to manually rotate the item.

What is a Swivel Handle Bolt? 47 Items

A Swivel Handle Bolt (BOLT,SWIVEL HANDLE) is an externally threaded fastener whose threaded and unthreaded portions are of one nominal diameter, No. 10 (0.190 IN.) (5 mm) or larger. It has a U-shaped head all of which is a greater diameter than the threaded and unthreaded portions, and has a nonremovable swivel handle used to manually rotate the item.

What is a Welding Bolt? 140 Items

A Welding Bolt (BOLT,WELDING) is an externally threaded fastener whose threaded portion is of one nominal diameter having small raised projections on the top side or underside of the head to facilitate welding the head. May or may not be designed to be held or turned with a wrench or inserted driver.

What is an Eye Bolt? 8697 Items

An Eye Bolt (BOLT,EYE) is an externally threaded device whose threaded portion is of one nominal diameter, without a head, but with the unthreaded end either bent more than 225 degrees (3.925 radians) or cast, forged, or punched to resemble an eye. See also BOLT, HOOK. Excludes CONNECTOR, ROD END.

What is a Shoulder Bolt? 14645 Items

A Shoulder Bolt (BOLT,SHOULDER) is an externally threaded fastener whose threaded portion is of one nominal diameter, No. 10 (0.190 IN.) (5 mm) or larger. It has a round unthreaded neck or shank all or part of which is of greater diameter than the threaded portion. The head is not designed to be held or driven with an inserted drivers. A locking feature may be incorporated in the design of the head or threads. For items with a thread diameter smaller than No. 10 (0.190 IN.) (5 mm) and those items with an inserted drive head, use SCREW, SHOULDER. For items which are No. 10 (0.190 IN.) (5 mm) or larger in size and are both shouldered and have an externally relieved body, use BOLT, EXTERNALLY RELIEVED BODY. Excludes THUMBSCREW.

What is a Firebrick Anchor Bolt? 32 Items

A Firebrick Anchor Bolt (BOLT,FIREBRICK ANCHOR) is a fastener designed for securing firebrick to the outer wall or casing of furnaces or boilers. Normally consisting of a straight or bent shank with a square or rectangular head and designed for high temperature application.

What is an Assembled Washer Bolt? 1628 Items

An Assembled Washer Bolt (BOLT,ASSEMBLED WASHER) is a BOLT, MACHINE on which has been assembled one or more nonremovable washers. See also SCREW, ASSEMBLED WASHER.

What is a Clevis Bolt? 1098 Items

A Clevis Bolt (BOLT,CLEVIS) is an externally threaded fastener whose threaded and unthreaded portions are of one nominal diameter and are separated by a narrow circumferential groove. The head is designed to be held or driven with an inserted driver. Excludes BOLT, SHEAR.

What is an Oval Neck Bolt? 56 Items

An Oval Neck Bolt (BOLT,OVAL NECK) is a headed externally threaded fastener whose threaded portion is of one nominal diameter with an elliptical neck, directly beneath the head.

What is a Hook Bolt? 1238 Items

A Hook Bolt (BOLT,HOOK) is an externally threaded device whose threaded portion is of nominal diameter, without a head but with the unthreaded end bent not over 225 degrees (3.925 radians). See also BOLT, EYE and BOLT, U.

What is an U Bolt? 4024 Items

An U Bolt (BOLT,U) is an externally threaded fastener bent approximately 180 degrees (3.141 radians) in the shape of the letter U and with both ends threaded.

What is an Internal Wrenching Bolt? 6361 Items

An Internal Wrenching Bolt (BOLT,INTERNAL WRENCHING) is an externally threaded fastener whose threaded portion is of one nominal diameter, No. 10 (0.190 IN.) (5 mm) or larger. It is designed with an internal socket or internal multiple spline for use with an internal driver. The head is beveled (conical) or cylindrical in shape. Items with cylindrical shaped heads must have an externally relieved body. A locking feature may be incorporated in the design of the head or threads. See also SCREW, CAP, SOCKET HEAD. Excludes SETSCREW; SCREW, SHOULDER; BOLT, SHOULDER; SCREW, EXTERNALLY RELIEVED BODY; BOLT, EXTERNALLY RELIEVED BODY; and SCREW, MACHINE.

What is a Tee Head Bolt? 1142 Items

A Tee Head Bolt (BOLT,TEE HEAD) is an externally threaded fastener whose threaded portion is of one nominal diameter and with a head specially designed to fit in a slot and hold against turning.

What is a Hanger Bolt? 40 Items

A Hanger Bolt (BOLT,HANGER) is a headless cylindrical threaded fastener which is threaded on both ends, one end being threaded to accommodate a nut and the other end having continuous wood screw type threads extending from a gimlet or cone point to the unthreaded portion. The unthreaded portion may have a ribbed shoulder.

What is an Externally Relieved Body Bolt? 5731 Items

An Externally Relieved Body Bolt (BOLT,EXTERNALLY RELIEVED BODY) is an externally threaded fastener whose threaded portion is of one nominal diameter, and whose unthreaded portion has been machined or ground in one or more places or over its entire length to a maximum diameter less than the minimum pitch diameter of the thread (excludes undercuts for thread relief). It is No. 10 (0.190 IN.) (5 mm) or larger in size and has a head which is not designed to be held or driven with an inserted driver or designed for rotation by the thumb and fingers. A locking feature may be incorporated in the design of the head or threads. Excludes BOLT, INTERNAL WRENCHING and THUMBSCREW. See also SCREW, EXTERNALLY RELIEVED BODY.

What is an Internally Relieved Body Bolt? 3391 Items

An Internally Relieved Body Bolt (BOLT,INTERNALLY RELIEVED BODY) is an externally threaded fastener whose external threaded portion is of one nominal diameter. It has a concentric hole along the longitudinal centerline which may extend a part or the full length of the bolt. The concentric hole along the centerline may be counterbored and/or internally threaded at the head end or the bolt end. The head is designed to be held or driven by an external and/or internal driver. For items having a hole(s) perpendicular to the axis which meet the concentric hole along the longitudinal centerline, see BOLT, FLUID PASSAGE.

What is a Shear Bolt? 22377 Items

A Shear Bolt (BOLT,SHEAR) is a high strength, 160,000 pounds per square inch (1100 megapascals) minimum tensile strength externally threaded fastener designed for use in applications involving great shear stress. The head is designed to accommodate an external wrench or driver. The head is not designed to be held or driven with an inserted driver, nor is it designed for rotation by the thumb and fingers. The unthreaded portion is of specific grip length, plated or unplated, and is machined to a tolerance of one thousandth (0.001) of an inch (0.025 mm) or less of a specific diameter for items one inch (25 mm) or less in diameter. Items over one inch (25 mm) in diameter shall have a tolerance of fifteen ten thousandths (0.0015) of an inch (0.038 mm) or less. The nominal major diameter of the threads shall be at least one thousandth (0.001) of an inch (0.025 mm) below the minimum shank diameter, but not below the minimum major diameter for applicable class of fit, as shown in the Screw Thread Standards, FED STD H28 and/or other nationally recognized standards. A locking feature may be incorporated in the design of the head or threads. See BOLT, MACHINE and BOLT, CLEVIS.

What is a Square Neck Bolt? 4065 Items

A Square Neck Bolt (BOLT,SQUARE NECK) is a headed externally threaded fastener whose threaded portion is of one nominal diameter, with a square neck directly beneath the head.

What is a Ribbed Neck Bolt? 251 Items

A Ribbed Neck Bolt (BOLT,RIBBED NECK) is a headed externally threaded fastener whose threaded portion is of one nominal diameter with a series of longitudinal ribs, splines or serrations on all or part of the unthreaded portion. See also BOLT, RIBBED SHOULDER.

What is a Finned Neck Bolt? 91 Items

A Finned Neck Bolt (BOLT,FINNED NECK) is a headed externally threaded fastener whose threaded portion is of one nominal diameter having two or more fins extending from the head to the shank.

What is a Key Head Bolt? 223 Items

A Key Head Bolt (BOLT,KEY HEAD) is a headed externally threaded fastener whose threaded portion is of one nominal diameter with a single rectangular or triangular projection on the underside of the head.

What is a Threaded End Rod? 3596 Items

A Threaded End Rod (ROD,THREADED END) is a headless cylindrical shaped metal item exceeding 12 inches (304.8 mm) in length and externally threaded on one or both ends. The unthreaded portion shall be of one diameter. Excludes items with tapered threads. See also STUD (as modified) and PIN, STRAIGHT, THREADED.

What is a Continuous Thread Rod? 2381 Items

A Continuous Thread Rod (ROD,CONTINUOUS THREAD) is a headless fastener exceeding 12 inches (304.8 mm) in length having an external thread of one nominal diameter running from end to end. See also STUD, CONTINUOUS THREAD.

What is a Ribbed Shoulder Bolt? 554 Items

A Ribbed Shoulder Bolt (BOLT,RIBBED SHOULDER) is an externally threaded fastener whose threaded portion is of one nominal diameter. It has a series of longitudinal ribs, splines or serrations on all or a part of the shoulder. The minor diameter of the ribs must be greater than the major diameter of the threads. See also BOLT, RIBBED NECK.

What is an Eccentric Head Bolt? 420 Items

An Eccentric Head Bolt (BOLT,ECCENTRIC HEAD) is an externally threaded fastener the head of which is usually flat with a periphery not concentric to the bolt shank. The head is not designed for wrenching. It may have a drive feature located at the threaded end, which can be used to rotate the screw and eccentric head into a locking position to secure a flanged or groove component.

What is a Drive Shank Bolt? 1045 Items

A Drive Shank Bolt (BOLT,DRIVE SHANK) is an externally threaded fastener, made of high strength metal, whose threaded portion is of one nominal diameter. The unthreaded portion is of a specific grip length, and is ground to a close tolerance in order to provide a drive fit in a specific size hole. It may be plated or unplated. The head is not designed to be driven by a screwdriver or wrench. The item is driven into the parts to be fastened by means of a mallet or similar item.

What is a Close Tolerance Bolt? 13082 Items

A Close Tolerance Bolt (BOLT,CLOSE TOLERANCE) is an externally threaded fastener whose unthreaded portion is of a specified grip length, plated or unplated, and is machined to a tolerance of one thousandth (0.001) of an inch (0.025 mm) or less of a specific diameter for items one inch (25 mm) or less in diameter. Items over one inch (25 mm) in diameter shall have a tolerance of fifteen ten-thousandths (0.0015) of an inch (0.038 mm) or less. The nominal major diameter of the threads shall be at least one thousandth (0.001) of an inch (0.025 mm) below the minimum shank diameter, but not below the minimum major diameter for applicable class of fit, as shown in the Screw Thread Standards, FED STD H28 and/or other nationally recognized standards. The head is not designed to be held or driven with an inserted driver, nor is it designed for rotation by the thumb and fingers. A locking feature may be incorporated in the design of the head or threads. For items having close tolerance, and fabricated from material having 160,000 pounds per square inch (1100 megapascals) minimum tensile strength, see BOLT, SHEAR. For items fabricated from material having less than 160,000 pounds per square inch (1100 megapascals) minimum tensile strength and not having a close tolerance, see BOLT, MACHINE.

What is an Assembled Sleeve Bolt? 367 Items

An Assembled Sleeve Bolt (BOLT,ASSEMBLED SLEEVE) is a headed, externally tapered or straight fastener with a flanged outer sleeve ground externally straight. The head is designed to accommodate an external hand or power operated wrench or driver. The fastener must be tightened or released by torquing a nut.

What is a Foundation Bolt? 36 Items

A Foundation Bolt (BOLT,FOUNDATION) is an item having a threaded portion of one nominal diameter with a body of various shapes, specifically designed for embedding in concrete, brick, or masonry. It is used for securing structural or other items. See also SHIELD,EXPANSION.

What is a Boiler Patch Bolt? 18 Items

A Boiler Patch Bolt (BOLT,BOILER PATCH) is an externally threaded fastener whose threaded portion is of one nominal diameter, without machined (or equivalent) surfaces, having a countersunk head surmounted by a square or hexagonal head to facilitate installation, after which the square or hexagonal head is removed. (Converted from AEUSA to General Use on 12152020)