Content with Quality

21 July 2022
It is Andrews Fasteners’ standard practice to supply customers a Declaration of Conformity and Test Certificates for purchased products (in general this is only on products grade 8.8 and above). These documents may not be supplied for every customer we serve, as we know, that some of them may not need them, or need them at a later time. We operate an automatic Test Certificates list where, for a customer who requests it with us, test certificates are sent automatically by our staff in the Quality Department every morning or through the working day once goods have been invoiced.
Read more about Can Andrews Fasteners send me a Test Certificate for the goods that I purchased?

16 June 2022
Hexagon Stud Connectors, also called Coupling Nut, are made based on withdrawn DIN 6334 standard. D s e m M6 10 11.05 18 M8 13 14.38 24 M10 17 18.90 30 M12 19 21.10 36 M14 22 24.49 42 M16 24 26.75 48 M18 27 29.56 54 M20 30 33.53 60 M22 32 35.03 66 M24 36 41.60 72 M27 41 45.20 81 M30 46 50.89 90 M33 50 55.
Read more about DIN 6334 Hexagon Stud Connector, Coupling Nut - General specification (coarse thread)

03 May 2022
The clamp length is the distance between the bolt head and the nut holding all the components together. It includes steelwork, any shims, plates and washers used. The grip length is the thickness of the steelwork (that includes plates, shims etc.) that can be gripped together by the bolt and nut assembly. It strictly depends on the specific application (how many washers are used in the assembly). Example For EN 14399-3 hexagon bolt assembly type HR , diameter M30 and 100mm in length, the reference clamp length will be between 48mm up to 69mm, whereas the grip length with one washer will be 44-63mm and two washers 40-57mm.
Read more about What is the difference between Clamp length and Grip length in EN 14399 assemblies?

08 April 2022
A chart of Metric Thread Pitches for bolts, studs and other fasteners covering from M1 to M100. Diameter Coarse Pitch M11 0.25 M22 0.4 M33 0.5 M4 0.7 M5 0.8 M6 M7 1 M8 M9 1.25 M10 M11 1.5 Diameter Coarse Pitch M12 1.75 M14 M16 2 M18 M20 M22 2.5 M24 M27 3 M30 M33 3.5 M36 4 Diameter Coarse Pitch M39 3 M42 M45 4.5 M48 M52 5 M56
Read more about Metric Thread Pitch Chart - Coarse Pitch

04 April 2022
Nominal size Inside diameter (d1) Outside diameter (d2) Thickness (s) nom. max. min. nom. max. min. nom max. min. M5 5.5 5.8 5.5 15 15 14.2 1.6 1.9 1.3 M6 6.6 7.0 6.6 18 18 17.2 2 2.3 1.7 M8 9 9.4 9.0 24 24 23.2 2 2.3 1.7 M10 11 11.5 11.0 30 30 29.2 2.5 2.8 2.2 M12 14 14.5 14.0 36 36 34.8 3 3.6 2.4 M16 18 18.
Read more about BS 4320 Basic dimensions Form G washers for selected sizes

08 February 2022
It is the requirement that the manufacturer of the EN 14399 assembly will supply them suitably lubricated. The lubrication can be applied either on the bolt thread (external) or the nut thread (internal). Andrews Fasteners, in a majority of cases, choose to apply lubrication on the internal thread of the nuts. Due to the method used to lubricate the nuts, typically they need to be immersed in lubricant in full. Depending on the type of process used, the appearance of the nuts can differ, especially on Hot Dip Galvanised (HDG) nuts.
Read more about The different appearance of lubricated nuts on EN 14399 assemblies

04 February 2022
Apart from dimensional differences ( bigger heads of bolts and bigger nuts on preloaded assemblies), the main difference is in the way how these goods are installed. Non-preloaded bolting assemblies are generally tightened to at least snug-tight. The connected components are drawn together to achieve firm contact without any specific preload. The “snug-tight” is generally referenced as tightening the assembly by one man using a normal-sized spanner without an extension arm until the wrench starts hammering.
Read more about What is the difference between preloaded and non-preloaded bolting assemblies?

25 January 2022
Dimensions for selected, most popular sizes Size (d) M12 M16 M20 M22 M24 M27 M30 M33 M36 M39 Pitch 1.75 2 2.5 2.5 3 3 3.5 3.5 4 4 Length tolerances Nominal length (l) 3000 2000 1000 Minimum/Maximum ±10.5 ±7.5 ±4.5 Nominal length (l) 500-420 400-320 300-260 240-190 Minimum/Maximum ±1.25 ±1.15 ±1.05 ±0.925 Nominal length (l) 180-130 120-85 80-55 50-35 30-20 18-12 10-8 6-5 Minimum/Maximum ±0.8 ±0.7 ±0.6 ±0.5 ±0.42 ±0.
Read more about DIN 976-1 Basic Dimensions for fully threaded studding, threaded bar, stud bolt

12 January 2022
We understand the difficulties by the end-users and purchasing departments in choosing the right components for different installation methods of High-strength structural bolting assemblies for preloading (HR) . Different installation methods and product grades may require additional components like DTI washers , hardened washers, bolt face or nut face washers. Sometimes, the number and type of component change, depending on which part is rotated (the nut or the bolt head).
Read more about Configurator for BS EN 14399 High-strength structural bolting assemblies for preloading (HR)

22 November 2021
Chemical Composition As per DIN 267-4 Class C max. Mn min. P max. S max. 4, 5 and 6 0.50 - 0.110 0.150 8 0.58 0.30 0.060 0.150 10 0.58 0.30 0.048 0.058 12 0.58 0.45 0.048 0.058 Mechanical Properties As per DIN 267-4 Property Class 4 Class 5 Class 6 Class 8 Class 10 Class 12 Proof load stress (N/mm^2) 400 500 600 800 1000 1200 Symbol |4| |5| |6| |8| |10| |12| Hardness Vickers HV5
Read more about DIN 267 Mechanical properties for Nuts