Nuts and anchor nuts are extensively used fasteners in a wide range of applications in defence, aerospace, automotive, construction, and many other industries.They come in countless combinations of types, sizes, thread types, materials finishes & protective coatings and conforming standards. In cases where nuts or nutplates coform to a certain Standard or alternative parts exist and can be offered meeting or exceeding required specifications, they are offered with their Standard part number or alternate part numbers may be supplied in lieu of the ordered, on the basis of stock conditions. 

Depending on the standard, the nuts and anchor nuts listed in our Web Platform for Supplies can be supplied either as OEM parts of their respective manufacturers or as parts of our own labelled (AVIATIONEU NEW ERA) product lines, intended as cost effective alternatives to the respective parts of OEM brands.

An overview of these fasteners is provided below.

Hexagon Nuts

Hexagon (aka Hex) nuts are widely used in aerospace, defence, and industrial applications. Their "Hex" name refers to their hexagonal (six-sided) shape, providing a secure grip, preventing slipping and making them well-suited for applications where a reliable and tight fastening is necessary. It also allows for easy tightening and loosening using common tools like wrenches or socket sets. They come in different types (such as standard, jam, prevailing torque, flange, heavy or castle / castellated hex nuts) each serving a unique fastening function, and combinations of materials and finishes (e.g. alloy steel cadmium plated, stainless steel (CRES), titanium alloys), and sizes in Imperial (inch) or Metric (mm) measurement systems. Like other fasteners, they comform to different military, aerospace or industrial standards, such as ISO, the U.S. Army & Navy (AN) or Mil Standard (MS) converted and replaced by NASM National Aerospace Standards (NAS) of the U.S. Aerospace Industries Association (AIA), those set by the American National Standards Institute (ANSI), often in cooperation with ASTM International and ASME (American Society of Mechanical Engineers), the German DIN LN aerospace standards, and many others.Despite the conversions, their superseded standards are still often used for the procurement of these fasteners. 

Aerospace hex nuts are offered by different manufacturers, like Howmet® Aerospace, Paolo Astori or others, in different materials and finishes (e.g. alloy steel cadmium plated, stainless steel (CRES) & titanium alloys), in Imperial (inch) or Metric (mm) sizes.Those from silver-plated stainless steel are typically used in high-temperature applications.

For more information on these fasteners please consult articles and other resources available in this repository.

Anchor Nuts (Nutplates)

Anchor nuts, aka nutplates, nut plates or anchor plates, are terms used interchangeably and relate to stamped sheet metal fasteners with an internally threaded tube and a plate with two clearance holes for rivets. Initially designed and still extensively used in aerospace applications, they are today also used in automotive, motorsports, and many other industries in blind mounted panel applications where hex nuts cannot be used or an attached nut is required for ease of maintenance.

Anchor nuts are usually riveted to a workpiece and they feature an internally threaded tube and a plate with two clearance holes for attaching rivets. They come in an extensive range of styles/configurations (fixed or floating, full size or miniatures, standard or reduced rivet spacing, single or double lug, corner, right-angled bodies, etc.), sizes, Imperial (in.) Unified or Metric ISO (M) thread types, materials (e.g. Carbon Steel, Steel alloys, CRES), finishes, such as Cadmium or Cadmium Free Zinc Nickel platings (compliant to EU Regulations) & protective coatings. Depending on their application, nutplates conform to different military, national & international aerospace or industrial standards including U.S. Military, ASME & ASTM, IFI, ANSI, ISO, the German DIN LN aerospace, British BS, Japanese JIS and others.

Some important considerations for selecting the appropriate nutplates for an application are briefly discussed below.

Fixed vs Floating 
Anchor nuts can be Fixed or Floating, the latter being easier to use due to their built-in nut (threaded hole) able to "float" slightly thus providing a convenient connection point for threaded rods, such as bolts, from the backside. After placing a floating anchor nut in the correct place, rivets can be driven through the holes so that it stays in place. A threaded rod can then be inserted into the floating anchor nut even if this is slightly off-center. The built-in nut will move around slightly, making it easier to connect the threaded rod to a floating anchor nut. 
In the case of Fixed anchor nuts, the built-in nut is static (i.e. without the capability to “float”) and the threaded rod must be positioned perfectly over the hole. Self-locking anchor nuts are those with a built-in locking mechanism preventing them from loosening over time from vibrations. 
Materials & Finishes 
Common materials used in anchor nuts are Steel and Carbon Steel Alloys such as 42CrMo4 steel and C1050 heat treated carbon steel , CRES (stainless steel) A-286 alloy, Brass,  Aluminum, INCONEL alloy or other alloys depending on the manufacturer. CRES A-286 alloy is iron-nickel-chromium based austenitic iron based material with additions of molybdenum and titanium  known for its good strength and oxidation resistance especially at temperatures up to 1300°F (700°C). It  is used in various components, such as aircraft and industrial gas turbines due to is high strength and superior fabrication. Alloy A286 characteristics include good machinability and oxidation resistance up to 800°C, very high corrosion resistance, high mechanical properties and strengths well retained up to 700°C and others. INCONEL is a registered trademark of Special Metals Corporation for a family of austenitic nickel-chromium-based superalloys. They belong to the family of austenitic nickel-chromium-based superalloys, oxidation-corrosion-resistant materials well suited for service in extreme environments subjected to pressure and heat.  
Different surface finishes available include anodizing, brushing, polishing, resin spraying, powder and black oxide coating, rust preventive oil, sandblasting, painting, different platings (laser engraving Zn, blue black Zn, Ni, Cr, Tin, Copper, titanium alloy galvanized, silver plating, electroplating, etc.) On the basis of selected product and availability, nutplates can be supplied with a dry film lube specified by the letter "L" in the respective part number. Those with countersunk rivet holes are specified by the letter "K" at the end of the part number.  
Imperial (in.) Unified or Metric System Threads 
Anchor nuts are offered in  different inch or metric thread types. Those with Unified form thread designations, such as UNC (unified coarse) or UNF (unified fine), have a fixed number of threads per inch with the thread major diameter preceding the designation (e.g. 9/16”UNC or 9/16”UNF). UNC is the most commonly used for general purpose applications but UNF threads have a slightly higher breaking load capacity than the UNC. Those with Metric ISO standard threads are designated by the letter M followed by the value of the nominal diameter (the max thread diameter) and the pitch separated by the sign “x”, both expressed in millimetres.  
Conforming Standards 
Anchor nuts conform to different military, national & international aerospace or industrial standards including U.S. Military, ASME & ASTM, IFI, ANSI, ISO, the German DIN LN aerospace, British BS, Japanese JIS and others.  

For additional information on nuts & nutplates complying with various Standards, please refer to the respective product presentations at our Web Platform for Supplies (shop.aviationeu.supplies), the separate presentations or media files available in this repository, or contact us.