The metric classes adhere to ISO standards, set by the International Standards Organisation, that apply across most industrialized nations. where e 1 is the distance between the center of the end bolt and the end of the plate measured parallel to the load direction, p 1 is the distance between the centers of neighboring bolts measured parallel to the load direction, and d 0 is the diameter of the bolt hole. The charts below gives the dimensions for Hexagon head, Socket cap, Low head socket cap, Socket countersink, Socket button and Shoulder screw with Metric Threads. Refer to the charts below, which show the ideal tightening torque for each bolt grade for a variety of sizes. The bolt’s class indicates its material strength, with higher numbers meaning higher tensile and yield strength.

bolts are made from quenched and tempered alloy steel and see the most use in heavy-duty applications. Compare the bolts you have with the diagrams below, then refer to the appropriate chart to see the ideal tightening torque. Generally used in timber to timber and timber to metal construction, these bolts incorporate a square neck to grip the hole in the timber when fitting, and therefore negates the need for any drive recess to be included on top of the head. The tensile stress area A s corresponds to the reduced cross-sectional area inside the threaded part of the bolt.

Otherwise the design resistance of a group of fasteners should be taken as the number of fasteners multiplied by the smallest design resistance of any of the individual fasteners as specified in EN1993-1-8 § 3.

M14 bzp hexagon head bolts are manufactured from steel and have a diameter of 14 mm, conform to DIN 931 spec, and have a partial thread.

that due to the nature of the surface finish on Unbrako products, some surface corrosion may be evident. The tensile stress area depends on the thread and it can be calculated according to ISO 898-1 Section 9.

is only valid when the bolt is used in holes with nominal clearance not exceeding the values given in the standard EN 1090-2 'Requirements for the execution of steel structures', as specified in EN1993-1-8 §3. 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. use in applications such as access panels, number plates and many anti-vandalism securing solutions.Therefore for countersunk bolts the calculated tension resistance F t,Rd should be reduced by a factor of 0. Westfield Fasteners Limited is a company registered in England and Wales with company number 07215583.

They have a proof load of 830 MPa, minimum yield strength of 940 MPa, and a minimum tensile strength of 1040 MPa. Download the Metric Clearance Hole Chart to save the chart as a PDF – useful to print out to have next to your tools. 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. The punching resistance of the bolt B p,Rd should be verified against the applied tensile load F t,Ed in accordance with EN1993-1-8 Table 3.For bolts with cut threads where the threads do not comply with EN 1090 the relevant resistances should be multiplied by a factor of 0. By approximately ignoring the corner rounding for a perfect hexagon the relation of the distance across points s' and the distance across flats s is s' = s / cos(30°) = 1. The resulting hole diameter d 0 for each type of hole (normal, oversize, short slotted, long slotted) is determined by adding the nominal clearance given in EN 1090-2 Table 11 to the nominal diameter d of the bolt. 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 calculated strength properties for coarse pitch thread bolts may be used conservatively for fine pitch thread bolts.