Bolt strain gauge installation / calibration service

Gauge Embedding/ Calibration Service for Bolts

The bolt fastening is used in a wide range of fields in modern society and is an indispensable element. Through the measurement of axial force applied to the bolts of machine structures, automobiles, aircraft, highways, bridges, segment fasteners, and other structures, it is possible to check and control the state of fastening (checking for looseness, overtightening, and the specified fastening force). This is also utilized for the measurement of bolt strength and the bolt fastening designs. We accept gauge installation for measuring the axial force of bolts. We will machine a hole in your supplied bolts, install the strain gauges for bolts, and perform load calibration. The installation on the existing bolts enables axial force control.

Bolt strain gauge installation / calibration service

Strain gauge installation service



Construction with any of embedded bolt gauges or surface-adhering gauges. We can also handle special-shaped bolts upon consultation. Usable in a wide range of temperatures from low to high temperatures.


Installation method Embedding type Surface bonding type
Sensor Embedding strain gauge Strain gauge
Operating temperature -30 to +100°C -40 to +150°C -10 to +80°C -40 to +150°C -269 to +80°C 40 to +80°C -40 to +300°C
Machining Machining hole diameter
Machining hole diameter
Ø1.6, Ø2.0
Surface processing
Applicable bolt M3 or more M6 or more M3 or more
others   Available with temperature measurement function   Axial force measurement, bending measurement, torque measurement

Processing method

There are two methods in strain gauge installation service. One is embedding, and the other is bonding. Choose between them according to the conditions of use.

Embedding: BTM series

A hole of 1.6mm or 2mm in diameter is drilled in the center of the bolt. The strain gauge is inserted into the hole and embedded with an exclusive adhesive. This method has the advantage of avoiding the gauge being damage by a washer, etc. while fastening the bolt.


Bonding: F, QF, ZF, CF series

Two strain gauges are bonded on both sides of the bolt shaft in axially symmetric positions to cancel the influence of bending. It is required to slightly scrape off the surface of the bolt shaft where the strain gauges are bonded, for the purpose of avoiding strain gauges being damaged while fastening the bolt or by contact of a washer. Choose strain gauges according to the usage conditions including temperature.

Calibration service


In order to achieve accurate measurement, we offer calibration service in which the bolt is calibrated with specified load. Instruments and calibration machines used for the calibration service are periodically calibrated and inspected by public institutions complying with the national standards.

Application example


Monitoring of axial force of bolts in joint parts

Wind turbine generator facilities are aimed at enlargement in the scale. Management of axial force is indispensable for the bolts used in joint parts of the structures, both in assembling process and in actual working condition. It is possible to continuously monitor the axial force by installing bolt strain gauges in some of the bolts used in the joint part.