What is TSK type? – Japanese spelter socket standards other than JIS

Are there only JIS type spelter sockets in Japan?

In fact, there is another type of spelter socket called TSK type.

Why can’t we use only JIS type? It has to do with the type of wire rope.


There are three main types of wire ropes specified in JISG3549.

The most common type is called a stranded rope, which is used in many situations, including cranes and ships.

The other types of rope specified are spiral rope and locked coil rope. These are wire ropes that can withstand greater force than stranded ropes.

JIS type is designed besed only for the strand rope (6×19 plating). Whereas, TSK type is designed to be compatible with all kinds of strand ropes / spiral rope / locked coil rope.

The spelter socket has evolved in line with the evolution of wire rope.

There are two types of TSK type spelter socket,

  • TSK standard type : all kinds of Stranded ropes
  • TSK strong type : Spiral rope and locked coil rope.

TSK Standard Open Spelter Socket

TSK Standard Closed Spelter Socket

TSK Strong Open Spelter Socket

TSK Strong Closed Spelter Socket


TSK spelter socket is developed by “TOKYO SEIKO”(TOKYO ROPE MFG. CO., LTD.), Japan leading manufacturer of wire rope, with a history of over 100 years. As a side note, one of the first shareholders of the company was “Eiichi Shibusawa” (who would later become the Japanese 10,000 yen bill). He was also involved in the establishment of the company.

An advantage of the TSK model is light weight, lighter weight makes it easier for workers to do connecting with wire ropes. It is achieved by using HQ metal (S35C) stronger than JIS type(S25C).

In Japan, TSK type spelter sockets are also widely used along with JIS type. TSK type spelter sockets are also used in ships, and we have received orders from overseas customers as well.

AUZAC will continue to move forward with the history of spelter sockets.