Nippon Kaiji Kyokai, known as ClassNK or NK, is a ship classification society. The Society is actively engaged in a growing range of ship related activities and services aimed at contributing to promoting the protection of human life and property at sea as well as protection of the marine environment.
The NK Mission:
ClassNK is dedicated to ensuring the safety of life and property at sea, and the prevention of pollution of the marine environment.
To achieve this mission ClassNK will: Focus on delivering the highest quality classification services, by the highest quality personnel, while maintaining its totally independent third party, non-profit status.
Focus on the development of relevant rules, procedures and guidance, and maintain and develop its commitment to scientific and technological research and development.
Maintain and develop its global operations in line with the needs of clients using its services. ClassNK has earned an outstanding reputation for its long-standing dedication to safeguarding life and property at sea and preventing marine pollution through the establishment of universally recognized standards for the design, construction and maintenance of ships and other marine structures.
The principal work of the Society's expert technical staff is to undertake surveys to ensure that the rules which it has developed are applied to newbuildings and existing ships to ensure their safety. The rules cover not only hull structures, but also propulsion systems, electrics,electronic systems, safety equipment, cargo handling gear, and various other areas. ClassNK's surveyors work in shipbuilding and repair yards and at ports across the world, wherever they may be called upon to examine the condition of a ship.
The Head Office is located in Tokyo and in Chiba, Japan, and there are branch offices at the major Japanese and overseas cities throughout the world. (see Contact us) As of the end of February 2019, the Society had 9,083 ships totaling over 252 million g.t. under class. This figure represents approximately 20 percent of the world merchant fleet currently under class.
Shipbuilding steel grades and equivalent are specified in the specifications of each classification society in the table below.
| ASTM A131 | Classification Society Standard | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| ABS | BV | CCS | DNV | GL | KR | LR | NK | RINA | |
| A131 A | ABS A | BV A | CCS A | DNV A | GL A | KR A | LR A | NK A | RINA A |
| A131 B | ABS B | BV B | CCS B | DNV B | GL B | KR B | LR B | NK B | RINA B |
| A131 D | ABS D | BV D | CCS D | DNV D | GL D | KR D | LR D | NK D | RINA D |
| A131 E | ABS E | BV E | CCS E | DNV E | GL E | KR E | LR E | NK E | RINA E |
| A131 AH32 | ABS AH32 | BV AH32 | CCS AH32 | DNV AH32 | GL AH32 | KR AH32 | LR AH32 | NK AH32 | RINA AH32 |
| A131 DH32 | ABS DH32 | BV DH32 | CCS DH32 | DNV DH32 | GL DH32 | KR DH32 | LR DH32 | NK DH32 | RINA DH32 |
| A131 EH32 | ABS EH32 | BV EH32 | CCS EH32 | DNV EH32 | GL EH32 | KR EH32 | LR EH32 | NK EH32 | RINA EH32 |
| A131 FH32 | ABS FH32 | BV FH32 | CCS FH32 | DNV FH32 | GL FH32 | KR FH32 | LR FH32 | NK FH32 | RINA FH32 |
| A131 AH36 | ABS AH36 | BV AH36 | CCS AH36 | DNV AH36 | GL AH36 | KR AH36 | LR AH36 | NK AH36 | RINA AH36 |
| A131 DH36 | ABS DH36 | BV DH36 | CCS DH36 | DNV DH36 | GL DH36 | KR DH36 | LR DH36 | NK DH36 | RINA DH36 |
| A131 EH36 | ABS EH36 | BV EH36 | CCS EH36 | DNV EH36 | GL EH36 | KR EH36 | LR EH36 | NK EH36 | RINA EH36 |
| A131 FH36 | ABS FH36 | BV FH36 | CCS FH36 | DNV FH36 | GL FH36 | KR FH36 | LR FH36 | NK FH36 | RINA FH36 |
| A131 AH40 | ABS AH40 | BV AH40 | CCS AH40 | DNV AH40 | GL AH40 | KR AH40 | LR AH40 | NK AH40 | RINA AH40 |
| A131 DH40 | ABS DH40 | BV DH40 | CCS DH40 | DNV DH40 | GL DH40 | KR DH40 | LR DH40 | NK DH40 | RINA DH40 |
| A131 EH40 | ABS EH40 | BV EH40 | CCS EH40 | DNV EH40 | GL EH40 | KR EH40 | LR EH40 | NK EH40 | RINA EH40 |
| A131 FH40 | ABS FH40 | BV FH40 | CCS FH40 | DNV FH40 | GL FH40 | KR FH40 | LR FH40 | NK FH40 | RINA FH40 |
| - | ABS AQ43 | BV AH420 | CCS AH420 | DNV A420 | GL A420 | KR AH43 | LR AH42 | KA43 | RINA A420 |
| - | ABS DQ43 | BV DH420 | CCS DH420 | DNV D420 | GL D420 | KR DH43 | LR DH42 | KD43 | RINA D420 |
| - | ABS EQ43 | BV EH420 | CCS EH420 | DNV E420 | GL E420 | KR EH43 | LR EH42 | KE43 | RINA E420 |
| - | ABS FQ43 | BV FH420 | CCS FH420 | DNV F420 | GL F420 | KR FH43 | LR FH42 | KF43 | RINA F420 |
| - | ABS AQ47 | BV AH460 | CCS AH460 | DNV A460 | GL A460 | KR AH47 | LR AH46 | KA47 | RINA A460 |
| - | ABS DQ47 | BV DH460 | CCS DH460 | DNV D460 | GL D460 | KR DH47 | LR DH46 | KD47 | RINA D460 |
| - | ABS EQ47 | BV EH460 | CCS EH460 | DNV E460 | GL E460 | KR EH47 | LR EH46 | KE47 | RINA E460 |
| - | ABS FQ47 | BV FH460 | CCS FH460 | DNV F460 | GL F460 | KR FH47 | LR FH46 | KF47 | RINA F460 |
from: http://www.classnk.or.jp/hp/en/
