Quality is the TRUE MEASURE
of productivity
(Peter F. Drucker)

Total Quality Management Systems
for hot forging and heat treatment bolts

Tohoku bolt introduced a Quality Management System to keep providing high quality reliable JIS products as Japanese Industrial Standards licensed factory. We obtained Japanese Industrial Standards written permission for “JIS E 1108 Dog spike” in October in 1952. Shortly after that, we obtained the other JIS written permission for “Hexagon heat bolt” and “Fish plate bolt”. Including the “Screw spike”, now, we obtained in total 3 JIS written permissions and 3 JIS certifications. In order to keep earning our clients’ confidence, we will proactively continue improving our quality management system.

The main qualification experience

General heat treatment Professional Skills Level 1
2 staff
Level 2
13 staff
Metal heat treatment Super Master program graduate
1 staff
Non-destructive test engineer
Magnetic particle examination Level 2
1 staff
Level 1
2 staff
Liquid penetration examination Level 1
1 staff
Ultrasonic inspection Level 1
1 staff
ISO internal auditor 6 staff
JIS quality management officer 1 staff

Our product certification

Certificated product name
Hexagon bolt
Japanese Industrial Standards No.
Certification No.
Grade or type

Certificated product name
Fish plate bolt
Japanese Industrial Standards No.
Certification No.

Certificated product name
Dog spike
Japanese Industrial Standards No.
Certification No.


Certification body
Certification No.

Main inspection equipment

    • Horizontal wet type magnetic
      particle flaw detector

  • 3000kN Universal Tensile tester 3000kN
    (press and bending)

    • Charpy Impact tester

    • Rockwell Hardness tester

  • Brinell Hardness tester

    • Micro Vickers Hardness tester

  • 1000kN Torque tester