Bolt Tension Tools

Sometimes Demands are Great

Precise and controlled bolt tensioning is one of the important considerations in modern construction due to concern for personal and operational safety. Hydraulic bolt tensioner was first used by ships’ engine builders. Today, the technique is commonly used in reactor boilers, pressure tanks, heat exchangers, cranes, machine foundations, diesel motors, turbines, compressors, oil/gas pipeline.

Sometimes There isn’t Much Space

Many places requiring bolt tensioning are hard to reach with standard tools on the market. We specialize in tailor‐made tools which are small and suitable to be used in areas where standard tools are too large to reach. As such, our clients are able to pre‐tension at areas previously not possible to reach.

Economy and Safety

Hydraulic bolt tensioning is not expensive to use compared with alternative ‘old‐fashioned’ tools that require extra manpower. Even the most careful tightening is not exact enough with conventional tools. Correct pretension of bolts reduce the risk of leakage and shut downs. Safety for the workers and the environment is important to us. No one can afford an accident.

We have Standardized Many Tools

We discovered early that we have to standardize our ‘special bolt tensioners’ and based them on a flexible system. Therefore, our customers are free to determine thread dimension, height, distance between the bolts, and other technical specifications. Our tools can fit any thread dimension. Behind our bolt tensioners are many years of experiences and development. Material quality, tolerance and the right seals are important factors when using high pressure. We can be your one‐stop supplier by delivering bolt tensioner, pumps, hoses, bolts and nuts, offshore operators, training and expertise.

Make-Up Tools

Our design is dependent on our costumers’ requirement and amount of space avaialable for pre‐tensioning. We have tools that are especially designed for weld necks and other standard flanges. We try to combine a variety of thread dimensions in our bolt tensioning tools.

If many bolts in a fixed OCO have to be tensioned, we can design a make‐up tool where all bolts are tensioned in one operation. This picture show different make‐up fixtures Bandak has produced.

We also Produce Bolts, Nuts and Washers

We design and manufacture bolts and nuts for the ship building, processing and offshore industry We can produce studbolts with rolling threads, from 8.8 – 12.9, delivered with 3.1 b.c certificate and DNV‐approved. Nuts and washers can be delivered in a range of sizes and according to current norms.


Hydraulic Nuts and Rings

In some applications, there is a need for permanent hydraulic tension tool to be operated immediately, for example for controlling the force on the operating conditions in the control system. We have good experience in hydraulic nuts or rings which act as both permanent nuts and bolts tensioners.

In other applications, fixed jigs with a number of bolt tensioners are preferred in order to achieve rapid and rational tensioning of the bolts, for examples in vessels’ diesel engines and in processing plants. Bandak Tools hydraulic nuts, rings and jigs are designed according to costumers’ specifications.

Torque Wrenches

There are some applications where bolt tensioners are not suitable due to bolts’ length. In this instance, hydraulic wrench can be the solution.

Instead of making changes to standard wrenches, we provide customized solutions when other wrenches are unusable. Examples of where our hydraulic wrenches are used on flanges on ships, cranes, valves, major press machines for scrap. With working pressure at 600 ‐1.000 bar, our tools are lightweight, powerful and economical.

Manufacturing experience since 1966

  • We have ready-designed tools for bolt sizes from M14 to M140
  • Tools, pumps, hoses and offshore personnel available for rent

For consultation, please contact

Håvard Øygarden
Senior Account Manager
Cell phone: + 47 977 35 152