BS ISO 6624-4:2016 pdf download – Internal combustion engines — Piston rings Part 4: Half keystone rings made of steel
1 Scope
This part of lS0 6624 specifies the essential dimensional features of half keystone rings made of steel,types HK,HKB and HKBA, having nominal diameters from 50 mm up to, and including,160 mm, used inreciprocating internal combustion piston engines for road vehicles and other applications.
2Normative references
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references,only the edition cited applies. For undatedreferences, the latest edition of the referenced document (inciuding any amendments) applies.
ISO 6621-4, Internal combustion engines —Piston rings — Part 4: General specifications
The half keystone ring types are specified in Tables 1 and 2 and Figures 1, 2 and 3. Their commonfeatures and the dimensions of those features are specified in Tables 3 to 6 and Figures 4 to 10. Table 7gives the force factors for the different ring types, while Table 8 gives the dimensions and forces of halfkeystone rings.
The common features and dimensional tables presented in this part of lSO 6624 constitute a broadrange of variables and, in selecting a particular ring type, the designer shall bear in mind the conditionsunder which it will be required to operate.
lt is also essential that the designer refer to the specifications and requirements of ISO 6621-34 andISO 6621-4 before completing selection.
4 Ring types and designation examples
NOTE For the angle of half keystone rings, the same definition and measurement apply as for keystone rings(see ISO 6621-2).
4.1 Type HK – Straight faced half keystone ring 7
4.1.1 General features
Figure 1 shows the general features of piston ring type HK.See Table 7 for dimensions and forces.
h3 values are calculated based on Annex A.
4.1.2 Designation
EXAMPLE Designation of a piston ring complying with the requirements of ISO 6624–4, being a 7° half keystone ring made of steel with a straight faced peripheral surface (HK), of nominal diameter d 1 = 60 mm (60),of nominal ring width h 1 = 1,2 mm (1,2), made of CrSi alloyed steel subclass 62 (MC62), and having a chromium plated peripheral surface with a minimum thickness of 0,1 mm (CR2). Parameters in parenthesis are used in the
ISO ring designation:
Piston ring ISO 6624-4 HK – 60 × 1,2 – MC62/CR2
4.2 Type HKB — Barrel faced half keystone ring 7°
4.2.1 General features
Figure 2 shows the general features of piston ring type HKB.
See Table 7 for dimensions and forces.
h 3 values are calculated based on Annex A.BS ISO 6624-4 pdf download.