ISO 898

ISO 898 is an international standard that defines mechanical and physical properties for metric fasteners. This standard is the origin for other standards that define properties for similar metric fasteners, such as SAE J1199 and ASTM F568M.[1] It is divided into five (nonconsecutive) parts:

1. Bolts, screws and studs with specified property classes – Coarse thread and fine pitch thread[2]

2. Nuts with specified proof load values – Coarse thread[3]

5. Set screws and similar threaded fasteners not under tensile stresses[4]

6. Nuts with specified proof load values – Fine pitch thread[5]

7. Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm[6]

With exception to part 7, which defines test standards, the parts of this standard define properties for fasteners made of carbon steel and alloy steel. The standards define that the testing must be performed at ambient temperatures, which is defined as between 10 and 35 °C (50 and 95 °F). The standards do not cover fasteners that would otherwise apply but require special properties, such as weldability or corrosion resistance.[2][3][4]

Part 1: Bolts, screws and studs with specified property classes – Coarse thread and fine pitch thread

Part 1 defines the mechanical properties of bolts, screws, and studs. It specifically applies to fasteners that have an ISO metric screw thread as defined in ISO 68-1. The properties are defined for M1.6-39 with coarse threads and M8-39 with fine threads. The diameter and pitch combinations must adhere to ISO 261 and ISO 262 and the thread tolerances must adhere to ISO 965 parts 1, 2, and 4.[2]

Part 1 does not specify properties for fasteners that have head geometries that reduce the shear strength of the fastener, such as low head screws and countersunk heads. It also excludes set screws, which are covered under part 5.[2]

Part 2: Nuts with specified proof load values – Coarse thread

Part 2 defines the mechanical properties for coarse threaded nuts up to an M39 size and a height of at least half the nominal diameter.[3]

Part 5: Set screws and similar threaded fasteners not under tensile stresses

Part 5 defines the mechanical properties for set screws and other fasteners not under tensile stresses. It defines properties for sizes M1.6 through M24.[4]

Part 6: Nuts with specified proof load values – Fine pitch thread

Part 6 is the same as part 2 except for fine threaded nuts that range from M8 to M39. Note that the working temperature range for these fasteners is −50 to 300 °C (−58 to 572 °F)[5]

Part 7: Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm

Part 7 defines how to perform torsional tests on bolts and screws that have a nominal diameter less than or equal to 10 mm. This standard only applies to short screws and bolts with a nominal diameter between 3 and 10 mm.[6]


  1. ^ Bickford & Nassar 1998, p. 154.
  2. ^ a b c d ISO 898-1:2009, retrieved 2009-06-12.
  3. ^ a b c ISO 898-2:1992, retrieved 2009-06-12.
  4. ^ a b c ISO 898-5, retrieved 2009-06-12.
  5. ^ a b ISO 898-6:1994, retrieved 2009-06-12.
  6. ^ a b ISO 898-7:1992, retrieved 2009-06-12.


Further reading

External links


ASTM F568M is an ASTM International standard for metric bolts, screws and studs that are used in general engineering applications. It is titled: Standard Specification for Carbon and Alloy Steel Externally Threaded Metric Fasteners. It defines mechanical properties for fasteners that range from M1.6 to 100 in diameter. The standard was withdrawn in 2012. and has been replaced by ISO 898-1This standard defines property classes, the metric equivalent of a screw grade, that are almost identical to those defined by ISO 898-1, except for the addition of the 8.8.3 and 10.9.3 classes. These two additional standards are fasteners that have the same mechanical properties as their base property class (i.e. 8.8 and 10.9), but are made from weathering steel.This is a standard set by the standards organization ASTM International, a voluntary standards development organization that sets technical standards for materials, products, systems, and services.

List of ASTM International standards

This is a list of ASTM International standards.

Standard designations usually consist of a letter prefix and a sequentially assigned number. This may optionally be followed by a dash and the last two digits of the year in which the standard was adopted. Prefix letters correspond to the following subjects:

A = Iron and Steel Materials

B = Nonferrous Metal Materials

C = Ceramic, Concrete, and Masonry Materials

D = Miscellaneous Materials

E = Miscellaneous Subjects

F = Materials for Specific Applications

G = Corrosion, Deterioration, and Degradation of MaterialsThis list may include either current or withdrawn standards. A withdrawn standard has been discontinued by its sponsoring committee. A standard may be withdrawn with or without replacement.

List of DIN standards

This is an incomplete list of DIN standards.

The "STATUS" column gives the latest known status of the standard.

If a standard has been withdrawn and no replacement specification is listed, either the specification was withdrawn without replacement or a replacement specification could not be identified.

DIN stands for "Deutsches Institut für Normung", meaning "German institute for standardisation". DIN standards that begin with "DIN V" ("Vornorm", meaning "pre-issue") are the result of standardization work, but because of certain reservations on the content or because of the divergent compared to a standard installation procedure of DIN, they are not yet published standards.

List of International Organization for Standardization standards, 1-4999

This is a list of published International Organization for Standardization (ISO) standards and other deliverables. For a complete and up-to-date list of all the ISO standards, see the ISO catalogue.The standards are protected by copyright and most of them must be purchased. However, about 300 of the standards produced by ISO and IEC's Joint Technical Committee 1 (JTC1) have been made freely and publicly available.

Nut (hardware)

A nut is a type of fastener with a threaded hole. Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together. The two partners are kept together by a combination of their threads' friction (with slight elastic deformation), a slight stretching of the bolt, and compression of the parts to be held together.

In applications where vibration or rotation may work a nut loose, various locking mechanisms may be employed: lock washers, jam nuts, specialist adhesive thread-locking fluid such as Loctite, safety pins (split pins) or lockwire in conjunction with castellated nuts, nylon inserts (nyloc nut), or slightly oval-shaped threads.

Square nuts, as well as bolt heads, were the first shape made and used to be the most common largely because they were much easier to manufacture, especially by hand. While rare today due to the reasons stated below for the preference of hexagonal nuts, they are occasionally used in some situations when a maximum amount of torque and grip is needed for a given size: the greater length of each side allows a spanner to be applied with a larger surface area and more leverage at the nut.

The most common shape today is hexagonal, for similar reasons as the bolt head: six sides give a good granularity of angles for a tool to approach from (good in tight spots), but more (and smaller) corners would be vulnerable to being rounded off. It takes only one sixth of a rotation to obtain the next side of the hexagon and grip is optimal. However, polygons with more than six sides do not give the requisite grip and polygons with fewer than six sides take more time to be given a complete rotation. Other specialized shapes exist for certain needs, such as wingnuts for finger adjustment and captive nuts (e.g. cage nuts) for inaccessible areas.

A wide variety of nuts exists, from household hardware versions to specialized industry-specific designs that are engineered to meet various technical standards. Fasteners used in automotive, engineering, and industrial applications usually need to be tightened to a specific torque setting, using a torque wrench. Nuts are graded with strength ratings compatible with their respective bolts; for example, an ISO property class 10 nut will be able to support the bolt proof strength load of an ISO property class 10.9 bolt without stripping. Likewise, an SAE class 5 nut can support the proof load of an SAE class 5 bolt, and so on.


A screw is a type of fastener, in some ways similar to a bolt (see Differentiation between bolt and screw below), typically made of metal, and characterized by a helical ridge, known as a male thread (external thread). Screws are used to fasten materials by digging in and wedging into a material when turned, while the thread cuts grooves in the fastened material that may help pull fastened materials together and prevent pull-out. There are many screws for a variety of materials; those commonly fastened by screws include wood, sheet metal, and plastic.

ISO standards by standard number

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