ISO 898 is an

international standard international standard is a technical standard developed by one or more international standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization is the International Or ...

that defines mechanical and

physical properties A physical property is any property that is measurable, whose value describes a state of a physical system. The changes in the physical properties of a system can be used to describe its changes between momentary states. Physical properties are o ...

for metric fasteners. This standard is the origin for other standards that define properties for similar metric

fastener A fastener (US English) or fastening (UK English) is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or disman ...

s, such as SAE J1199 and

ASTM F568M 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 ...

.. It is divided into five (nonconsecutive) parts: 1. Bolts, screws and studs with specified property classes – Coarse thread and fine pitch thread. 2. Nuts with specified proof load values – Coarse thread. 5. Set screws and similar threaded fasteners not under tensile stresses. 6. Nuts with specified proof load values – Fine pitch thread. 7. Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm. With exception to part 7, which defines test standards, the parts of this standard define properties for fasteners made of

carbon steel Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: * no minimum content is specified or required for chromium, cobalt ...

and

alloy steel Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low alloy steels and high alloy steels. The differe ...

. The standards define that the testing must be performed at

ambient temperature Colloquially, "room temperature" is a range of air temperatures that most people prefer for indoor settings. It feels comfortable to a person when they are wearing typical indoor clothing. Human comfort can extend beyond this range depending on ...

s, which is defined as between . The standards do not cover fasteners that would otherwise apply but require special properties, such as

weldability The weldability, also known as joinability,. of a material refers to its ability to be welded. Many metals and thermoplastics can be welded, but some are easier to weld than others (see Rheological weldability). A material's weldability is used to ...

corrosion resistance Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

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 A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to fa ...

, and studs. It specifically applies to fasteners that have an ISO metric screw thread as defined in

ISO 68-1 ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...

. 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 The ISO metric screw thread is the most commonly used type of general-purpose screw thread worldwide. They were one of the first international standards agreed when the International Organization for Standardization (ISO) was set up in 1947. Th ...

and

ISO 262 The ISO metric screw thread is the most commonly used type of general-purpose screw thread worldwide. They were one of the first international standards agreed when the International Organization for Standardization (ISO) was set up in 1947. Th ...

and the thread tolerances must adhere to

ISO 965 ISO 965 (ISO general purpose metric screw thread—tolerances) is an International Organization for Standardization (ISO) Standardization, standard for metric screw thread tolerances. It specifies the basic profile for ISO general purpose metric sc ...

parts 1, 2, and 4. Part 1 does not specify properties for fasteners that have head geometries that reduce the

shear strength In engineering, shear strength is the strength of a material or component against the type of yield or structural failure when the material or component fails in shear. A shear load is a force that tends to produce a sliding failure on a materia ...

of the fastener, such as

low head screw Low or LOW or lows, may refer to: People * Low (surname), listing people surnamed Low Places * Low, Quebec, Canada * Low, Utah, United States * Lo Wu station (MTR code LOW), Hong Kong; a rail station * Salzburg Airport (ICAO airport code: LOW ...

s and countersunk heads. It also excludes

set screw In American English, a set screw is a screw that is used to secure an object, by pressure and/or friction, within or against another object, such as fixing a pulley or gear to a shaft. A set screw is normally used without a nut (which distingu ...

s, which are covered under part 5.

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.

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

Part 5 defines the mechanical properties for

s and other fasteners not under

tensile stress In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a force it will cause elonga ...

es. It defines properties for sizes M1.6 through M24.

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

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 test In the field of solid mechanics, torsion is the twisting of an object due to an applied torque. Torsion is expressed in either the pascal (Pa), an SI unit for newtons per square metre, or in pounds per square inch (psi) while torque is expressed ...

s 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.

References

Bibliography

External links

Mechanical properties of common ISO property classes
{{DEFAULTSORT:Iso 898 #00898 Screws