Convex countersunk nut HEFB A4 M4 - OEM

A4 stainless steel A4 steels, alloyed with molybdenum, are "acid resistant" and provide better corrosion resistance. A4 is used extensively in the cellulose industry, since this grade of steel was developed for boiling sulphuric acid. It is also suitable to some extent for chloride environments. A4 is also frequently used in the food and shipbuilding industries. Below is a table of technical dimensions (by size):d nominalPasd1fhM30,560,552,10M40,780,603,20M50,8100,653,60M61121,104,50M81,25161,606M101,5201,907,50M121,75242,409,60 Threads A thread is a helical shaping operation carried out on a rod, a tube, a nut or in the bore of a mechanical part, to enable it to be fixed. A screw is threaded, a nut is tapped. The screw pitch corresponds to the relative distance covered in translation by a screw in relation to its nut during a complete turn. For example, a screw with a pitch of 1.25 will advance 1.25 mm during one revolution for a metric pitch. The term 'screw pitch' is often incorrectly used to refer to threads. For bolting products, there are a multitude of pitches: ISO (fine and coarse), American (UNC, UNF...), Gas, English (BSW), trapezoidal... At Deal Marine we offer a range of screws and nuts with standard pitches (metric, fine) or more specific pitches such as American (UNF, UNC). For more information on screw threading, please click on the "Info" button. Subscribe to our Newsletter: Subscribe I accept the terms and conditions and the privacy policy