ISO 898 is aninternational standard that defines mechanical andphysical properties formetric fasteners. This standard is the origin for other standards that define properties for similar metricfasteners, such asSAE J1199 andASTM 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]
3. Flat washers with specified property classes[4]
5. Set screws and similar threaded fasteners not under tensile stresses[5][6]
6. (Now withdrawn) Nuts with specified proof load values – Fine pitch thread[7]
7. Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm[8]
With exception to part 7, which defines test standards, the parts of this standard define properties for fasteners made ofcarbon steel andalloy steel. The standards define that the testing must be performed atambient 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 asweldability orcorrosion resistance.[2][3][5]
Part 1 defines the mechanical properties of bolts,screws, andstuds. It specifically applies to fasteners that have an ISO metric screw thread as defined inISO 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 toISO 261 andISO 262 and the thread tolerances must adhere toISO 965 parts 1, 2, and 4.[2]
Part 1 does not specify properties for fasteners that have head geometries that reduce theshear strength of the fastener, such aslow head screws andcountersunk heads. It also excludesset screws, which are covered under part 5.[2]
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 3 defines the mechanical and physical properties of flatwashers, designed to be used in bolted joints in combination with other fasteners.[4]
Part 5 defines the mechanical properties forset screws and other fasteners not undertensile stresses. It defines properties for sizes M1.6 through M24.[5]
Part 6 has been withdrawn as of 20212 and been replaced by ISO 898-2:2012. It used to be 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)[7]
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.[8]
