They are designated as above also including the pitch of thread in mm e.g. M8 × 1, M14 × 1.5, M27 × 2 etc. The defined diameter of metric bolts is actually slightly larger than the actual diameter of the bolt shaft. So an M8 bolt would have a shaft diameter that’s slightly under 8mm which means that the bolt should fit through an 8mm hole. But it’s common practice to drill clearance holes that are slightly larger to allow for misalignment. Bulgarian, Croatia, Cyprus, Estonia, Hungary, Latvia, Lithuania, Malta, Romania, Slovakia, Slovenia

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For full table with more Property Classes - rotate the screen! Metric Bolts - Coarse Threads - Proof Loads Thread This abbreviated format omits the pitch definition which means that the bolt has a coarse thread. Whenever the pitch dimension is omitted from a metric bolt specification then the bolt is always coarse threaded. This example (M12-50) has a diameter of 12mm and a length of 50mm. Metric Thread Pitch The tensile stress area A s corresponds to the reduced cross-sectional area inside the threaded part of the bolt. According to EN1993-1-8 § 3.8(1) for long joints where the distance between the centers of the end fasteners measured in the direction of load transfer is more than 15 d the design shear resistance F v,Rd of all the fasteners should be multiplied by the reduction factor β Lf specified in EN1993-1-8 equation 3.5. According to EN1993-1-8 § 3.6.1(4) the design shear resistance F v,Rd should only be used where the bolts are used in holes with nominal clearances not exceeding those for normal holes as specified in EN 1090-2 'Requirements for the execution of steel structures'.

Minimum and maximum spacing p 1, p 2 and edge distances e 1, e 2 for bolts are given in EN1993-1-8 Table 3.3. The minimum values are: e 1≥ 1.2 d 0, e 2≥ 1.2 d 0, p 1≥ 2.2 d 0, p 2≥ 2.4 d 0, where d 0 is the diameter of the hole, e 1, p 1 are measured parallel to the load transfer direction and e 2, p 2 are measured perpendicular to the load transfer direction. Minimum end distance, edge distance, and spacing for bolt fasteners according to EN1993-1-8 Table 3.3 (rounded up to nearest mm) Nuts and bolts are essential fastenings, critical in the safe assembly of machinery, equipment, furniture and much more. In most circumstances, it’s absolutely vital that the right size of fastening is used. In this brief guide we provide an introduction to standard ISO metric sizes for nuts and bolts which will hopefully help dispel any confusion. BS3643 Parts 1&2 A is the appropriate area for shear resistance. When the shear plane passes through the threaded part of the bolt A is equal to the tensile stress area of the bolt A s. When the shear plane passes through the unthreaded part of the bolt A is equal to the gross cross-sectional area of the bolt A g. Hex bolts from ITA Fasteners are mostly used in repair and construction work. As the name implies, they have a hexagonal head and come with machine threads for a firm and rough handling. They come in a wide range of different hex bolt sizes for custom applications depending on its dimensional requirements. These Hex Bolts come in the anti-corrosion stainless steel, alloy steel and carbon steel materials which ensures that the structure doesn’t weaken because of rust. Depending on the length of the bolt, it can come with standard threading or full threading.

Shear strength of bolts

Metric nuts and bolts are commonly referenced using ‘M’ sizes, for example: M3, M8, M12. But the size of a metric fastener is more accurately specified using diameter, pitch and length dimensions, in millimeters. For nuts the size dimensions used are simply diameter and pitch. And BS3643 part 2 provides tabulated diameters and tolerances for coarse and fine pitch threads, based on ISO 965/2. Metric Bolt Sizes The number 1.0 is the thread pitch of the bolt, which is the distance between threads, in millimeters. The standard coarse pitch thread metric bolt sizes are: M3, M3.5, M4, M5, M6, M7, M8, M10, M12, M14, M16, M18, M20, M22, M24, M27, M30, M33, M36, M39.

Metric bolts and fasteners are manufactured in conformance with standards set by the International Organisation for Standardisation (ISO) and the German Institute for Standardisation (DIN). Here’s a list of the most common DIN and ISO numbers and what they describe. Descriptions of DIN and ISO fastener standards. Standard No. According to EN1993-1-8 Table 3.4 the shear strength of the bolt may be based on the tensile stress area. In general the stress area of fine pitch thread bolts passing through the threaded part is larger as compared to the coarse pitch thread bolts. As noted, the specification of metric bolts includes the definition of thread pitch, but if this is omitted then a coarse pitch is assumed. Metric fasteners are available with either coarse or fine thread pitches with some metric bolt sizes offering extra fine thread pitch options. It is worth noting that metric bolts with a coarse thread pitch have more threads per inch (they are more closely spaced) than comparable imperial bolts. List of common metric bolt sizes. Metric Coarse The yield strength f yb and the ultimate tensile strength f ub for bolt classes 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, and 10.9 are given in EN1993-1-8 Table 3.1.The first number of the bolt class corresponds to the ultimate strength e.g. 400 MPa for classes 4.x, 500 MPa for classes 5.x, 600 MPa for classes 6.x, 800 MPa for classes 8.x, and 1000 MPa for classes 10.x. Austria, Azores, Czech Republic, Denmark, Finland, Greece, Italy, Madeira, Poland, Portugal, Spain, Sweden For standard coarse pitch thread and fine pitch thread bolts the nominal stress area A s is provided in ISO 898-1 Tables 4 to 7. The standarized properties of metric bolts are specified in the international standard ISO 898-1:2009 'Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1: Bolts, screws and studs with specified property classes - Coarse thread and fine pitch thread'.