4Tightening
Reliability

4-1. Characteristic Factors of Defects in Bolt Tightening
Characteristic factors (4M's) ofdefects in bolt tightening ─────── 46

4-2. Characteristic Cause Diagram of Defective Joints
Characteristic cause diagram ofdefective joints ────────── 47

4-3. Bolt Tightening Reliability
Bolt tightening reliability andtightening work ────────── 48

4-4. Machine Error(1) Machine error ───────── 49(2) Joint coeﬃcient ───────── 51

4-5. Human Error(1) Human error ────────── 53(2) How to use torque tools ───── 56

4-6. Bolt Tightening Reliability and Bolts
Bolt tightening reliability andbolts ────────────── 58

4-7. Construction of a Tightening Reliability System
Construction of a tightening
reliability system ────────── 59

4-8. Shifting from Torque Control to Tightening Assurance System(1) Tohnichi tightening assurance system ─ 60
(2) System conﬁguration examples ─── 62

44

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

Chapter

What is Tightening Reliability?

4

Bolt tightening reliability simply means tightening bolts properly.
However, depending upon the circumstances there are the following

Tightening Reliability

assurance levels.

1. To pass tightening inspections (by retightening)
2. To tighten bolts to the required torque (within
the tolerance) speciﬁed by the drawings
3. To tighten bolts up to the required initialtightening force (initial axial tension)
4. To tighten bolts up to the required working
tightening force (axial tension)
5. To achieve the maximum performance of the bolt
by using only parts or bolts that are in good condition
which do not easily loosen or break and do not create leaks
from bolted joints.

Even if the tightening torque is kept constant, the initial
axial tension generated will greatly vary. Therefore,
the target of bolt tightening reliability by the torquemethod is not to keep the axial tension fixed, but
to maintain it within the given dispersion width. It is
important not only to improve the reliability of thebolt tightening work, but also to link it with one of theassurance levels listed above to avoid generating any
problems even if the axial tension used is varied. This is
the feature of bolt tightening reliability .

Technical Data

45

Chapter

4-1

Tightening Reliability

Characteristic Factors of Defects in Bolt Tightening

Characteristic factors(4M s) of defects in bolt tightening

1.
2.
3.
4.

46

MAN ─────────── Missed tightening(Tightening operator human error)

Improper tightening tool usage

METHOD ───────── Wrong tightening value speciﬁcation(Improper tightening specification)

Wrong tightening procedure
Wrong tightening tool selection

MACHINE ──────── Inaccuracy(Improper tightening equipment) Mechanical failure

MATERIAL ──────── Part out of tolerance(Improper screw joint material)

Defective part material
Insuﬃcient screw part lubricant

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

4-2

Tightening Reliability

Characteristic Cause Diagram of Defective Joints
Chapter

Characteristic cause diagram of defective joints

Design quality failure●Expected failure of required tightening torque●Insuﬃcient strength of bolt joint part●Expected failure of drop in initial tightening force●Indication failure of tightening operation●Insuﬃcient loosening measures●Inapplicability of tightening tools●Inapplicability of tightening inspection

Improper tightening
work by operator●Incorrect tightening procedure●Improper handling of tools by operator●Missed tightening by operator●Failure in instruction to operator

Improper tightening
tools●Change in condition of tightening tool
●Function failure of tightening tool
●Decrease in accuracy of tightening tool
●Improper selection of tightening tool

Defective bolt joint●Change in torque coeﬃcient●Change in condition of friction part of screw●Process failure of bolt
●Insuﬃcient strength of bolt
●Size error of bolt
●Defective right angle of bearing surface

Failure in the ﬁeld

●Insuﬃcient education of operator●Failure to check for loosening of bolts●No proper tightening tools available●Insuﬃcient instruction for tightening spec

System failure●Insuﬃcient standardization of bolt tightening●Insuﬃcient indication of tightening speciﬁcation●Insuﬃcient monitoring for tightening failure●Insuﬃcient system of bolt tightening●Insuﬃcient training in bolt tightening

Technical Data

4
Tightening Reliability

Chapter

Defective Screw Joint●Damage of joint●Loose fastening●Fixing failure of the bolted joint●Heat or current conduction defect●Leakage of oil or gas

47

4-3

Tightening Reliability

Bolt Tightening Reliability

Bolt tightening reliability and tightening work
Bolts generate clamping force and can only show
their performance after proper tightening work has
been completed. However, we cannot correctly check

Figure 4-1. Accuracy of tightening torque and dispersion of tightening tension

whether a bolt has been correctly tightened or not after

Dispersion width of tightening tension σ
3the bolt has been tightened. It is therefore importantthat the operator checks the tightening accuracy while
performing the tightening work rather than by carryingout an inspection after the work has been completed.
This is called containing the quality while tightening .
The factors that obstruct the reliability of the tightening
work are classified into two categories: machine error
due to the tightening tool and human error caused by
the operator.

%

In general, tightening tools are classiﬁed by tightening50

トルク係数のDispersion width of
torque coeﬃcient
バラツキ幅
3σ±30％3σ±30%
40

30

±20%

20

±10%
（Fcon）

10±

Chapter

accuracy into three categories shown in Table 4-1. The
allowable tolerance of the tightening torque should be

0

10

20

30

40

Dispersion width of tightening torque 3 σ± %appropriately decided and standardized based upon
the relation with the allowable dispersion width. Evenif tightening is carried out at a higher accuracy thanrequired, the variation in tightening force will not havemuch eﬀect.
Table 4-1. Tightening method classiﬁcations
MethodMechanism

Accuracy range (3σ)

Tightening Tool

①By guesswork

The operator judges the tightening condition according
to the force or sound, and stops the tightening work.

Over ±30%・Manual wrench・Manual screwdriver・Impact wrench(no torque control)②By maximum capacity

The bolt is tightened by adjusting the pressure or
current until the motor stalls or the clutch slips.

±10〜30%・Stall type・Slip clutch type・Impact wrench(control type)③By torque detection

The tightening torque is measured, and when the required
torque is reached the tightening is stopped.

Within ±10%・Torque wrench
・Mechanical type torque control
・Electric type torque control

48

TOHNICHI TORQUE HANDBOOK Vol.8

4-4

TECHNICAL DATA

ChapterTightening Reliability

Machine Error
Chapter（1）Machine error■ Periodic calibrations

For any tightening tool, sooner or later the tightening torque

Periodic calibrations are different from the daily

will change and the accuracy will go out of tolerance due

checks, in that it is necessary to precisely

to wear of the tightening tool. In most cases, however, themeasure the accuracy of the torque tools to

operator will be unaware of the change, resulting in defects ofassure the torque tools used for the work. Onea large quantity of products. There are two methods required tocommon problem of power tightening tools is

be carried out to recognize changes in the tightening torque.

that the calibration results often differ from theactual tightening torque. (P.51 Figure 4-2) ThisThe first method uses daily inspections anddifference is due primarily to the fact that theperiodic calibrations to regularly confirm thecalibration procedure does not accurately replicate

operating torque of the tightening tool.

the joint hardness or softness (joint coefficient)and it will be important to simulate the actual bolt
tightening conditions.

■ Daily inspections

Periodic calibrations（Tester + PC + Management software）

Daily inspections of torque tools before and after
carrying out the work keep the occurrence of problems
to a minimum. Tools for daily inspections are arranged
P398

TF

▲

TCF+TP▲

to be easy to operate and take the minimum of time.

P374

Daily inspections（Checker + PC + Management software）

P420

LC3-G

▲

R-DT999

▲

P378

▲

▲

ST2

▲

DOTE3-G
CD5

P368

P416

P376

PC

Management software

Note that the checkers and testers used for checking

PC
Management softwareand calibration must themselves be calibrated regularly,
and it will be necessary to establish traceability.

Technical Data

49

4
Tightening Reliability

2 methods to ﬁnd a change of tightening torqueChapter

4-4

Tightening Reliability

Machine Error

The second method is to sample the tightened bolts andcheck them by using the retightening torque inspection
method to assume the tool tightening torque.
■ Inspection data management system
Through the development of electronic
instruments, tightening tor que value andretightening torque values can be monitored
and furthermore, recorded. The recorded data
can be submitted to a third party for proof inprotection against product liability. However, themonitoring should use a measuring system that

Digital Torque Wrench

is independent from the control system of the

CEM3-G-BT

tightening torque. Otherwise, trouble within the▲／

CTB2-G-BT
▲

P282

P294

control system cannot be observed.
Wireless Link▲

Inspection Data Management System

P314

Using this method, the degree of wear and thetendency of the tightening tools can be predicted

Wireless Link

and as a result, preventive maintenancebecomes possible. Accidental accuracy defects
do not usually occur in tightening tools, but ifPCthey do, they result in defects in a large quantityof products. Therefore, it is preferable to keep
the tool within a repairable range even if thiswould result in some possible defects relating
to the frequency of the periodic calibration
retightening inspection.

50

TOHNICHI TORQUE HANDBOOK Vol.8

4-4

TECHNICAL DATA

ChapterTightening Reliability

Machine Error

Chapter（2）Joint coeﬃcient［2］Meaning of the joint coeﬃcient

discussed, only the tightening torque is considered and① To make the explanation easier, when the relation of

the rotation of the screw is neglected. But when dynamic

the torque and amount of rotation (rotation angle) is

characteristics (over-torque measures in nut runners) are

shown by a straight line, the right formula results. e =discussed, the way the tightening torque increases with

10 means that the tightening torque is reached fromthe rotation of the screws will become a problem. While─ rotation or ⊿θ = 36°
snug torque at ⊿n = ─10this is generally known qualitatively as a soft joint or hardjoint , it will be necessary to express this quantitatively.

1② As the joint coeﬃcient (e) is a non-dimensional ﬁgure, it
is not changed by the size of the screw.

The joint coeﬃcient (e) is identiﬁed and written as follows.

［1］Deﬁnition of joint coeﬃcient (e)The relation between the tightening torque and rotation
for a screw is shown in Figure 4-2. The joint coeﬃcient (e)at T = T0 for this joint is deﬁned as shown in Formula (1).

1 dT……Formula（1）
T0 dn T=T0
n：Number of screw turns
T0：Tightening torque

e=

1
⊿n
1
e

or

⊿ T=T0
e=

360
⊿θ

360
⊿θ = eFigure 4-3
T

（ ）

T0

Actual relation

θ=360n dθ=360dn
e=

1 ⊿T
・
T ⊿n

⊿ n=

Use the rotation angle (θ) in Formula (2)

e=

e=

⊿T

Snug point

360 dT……Formula（2）
T0 dθ T=T0

（ ）θ:Rotation angle of the screw（°
）

⊿n
⊿θ

n,θ

Figure 4-2
T
T0

dT

（dn）T=T0nTechnical Data

51

4
Tightening Reliability

When the static characteristics of torque tools areChapter

4-4

Tightening Reliability

Machine Error［3］Methods of obtaining the joint coeﬃcient① Method by drawing
Measure the tightening torque and amount of rotation (angle) from the

Figure 4-4TT0

actual screw. (In this case, the origin of the rotation amount, the angle, canbe neglected.) Plot on the drawing as shown Figure 4-4, and determine ⊿no r ⊿θ from the tangent of the prescribed tightening torque (To).
(e) can be calculated from formulas (3)and (4).

e=

1
⊿n

……Formula
（3）

e=

360
⊿θ

……Formula
（4）

0

⊿n
⊿θ

T0=0

θ

② Simple method
Tighten up to 80% of the tightening torque (T0). Then, use the formula (5) to
calculate (e) from the rotation angle (⊿θ)at the time of retightening up to To.

72……Formula
（5）
θ=
⊿θ'
e=

360 T0 -0.8T0
・
T0
⊿θ'

Example of actual joint coefficient measurement.
*Using the (2) simple method above
Bolt: M8
Tightening torque (T0): For 13.4 [N・m], 0.8T0 willbe 10.7 [N・m]① Preparation
Place a protractor on the outside of the measuring bolt. (The protractor
should have a hole so that the bolt will be in the center.)
Set the line so that the index is on the outside of the socket.

③ Calculation72= 72 =10
From the simple method formula e=

⊿θ

7.2

Medium joints can be calculated from this formula

Figure 4-5
T
13.4
10.7

T0
0.8T0

② Measurement
Tighten up to 0.8T0 (10.7 [N・m]).
Next, align the index of the protractor to 0 .
Then tighten to T0 (13.4 [N・m])and read the angle (7.2°).
7.2°

52

θ

TOHNICHI TORQUE HANDBOOK Vol.8

4-5

TECHNICAL DATA

ChapterTightening Reliability

Human Error
Chapter（1）Human error
For the reliability of the tightening work, human error is the most diﬃcult problem. We know that people make mistakes due to human nature. It isalso diﬃcult to observe any human errors by machine. We always have to take into consideration the fact that human error can be reduced through4

Among human errors, missed tightening is the number one problem. In order to tighten bolts eﬀectively and uniformly, bolts are tightened to therequired torque after ﬁrst carrying out provisional tightening. But in this case the provisionally tightened bolts, which are visually indistinguishable fromfully tightened bolts, may be felt not fully tightened. Since this kind of human error happens accidentally, it is very diﬃcult to ﬁnd the error by doing asampling test.
In order to eliminate missed tightening it is important to conﬁrm that the bolts have been fully tightened at the same time of full tightening.
Among the conﬁrmation methods, there is the counting method, in which a tightening completion signal is output upon reaching the set torque andcounted by a counter. There is also the monitoring method where OK/NG judging is carried out based on the tightening torque value, and the marking
method in which the torque wrench operation applies a mark to the head of the bolt. By selecting the method that best matches each of the work
environments it will be possible to prevent missed tightening.
Among relatively frequent human errors are erroneous operations such as stopping pulling the torque wrench before completion of tightening andreleasing the trigger of a power tool.

Technical Data

53

Tightening Reliability

education. Tightening by a human operator means that at the same time the operator can execute a visual inspection in which they can observe bolt
tightening defects, such as machine errors and galling. This visual inspection is a very eﬀective method to improve the reliability of the bolt tightening.

Chapter

4-5

Tightening Reliability

Human Error

As tightening conﬁrmation methods, there is the

Example of ID recognition from Thin
Client (PC) using the FH receiver RS232C output.

signals that are output each time the set torque■is attained. There is the monitoring method,

use when carrying out tightening of two positions on one

where OK/NG judgment is carried out using thework piece. When the body No. indication is received fromtightening torque values, and there is also thethe PLC(Programmable Controller), the tool will become

marking method, in which a mark is applied to theable to conduct tightening. At part A, torque wrench A

bolt head simultaneously with the operation of theis used to tighten three bolts. When tightening has been

torque wrench. By selecting the method according

completed, the tightening bolts at part B will be displayed,

to each of the operating environments, it will be

and it will be possible to conduct tightening. Using torquepossible to prevent missed bolt tightening.

wrench B, the two bolts are tightened, and when the workcounter method in which a counter is used tocount up the number of tightening completion

This is a wireless error-proofing (Pokayoke)system forhas been completed an OK signal is output to the PLC.

Counter method

If torque wrench B is used for tightening at part A, an

When the set torque is attained, the tightening

error occurs and the display will appear in red to indicatecompletion signal is output and the signal isa warning as an error check to ensure that the correct

counted up by the counter (CNA-4mk3) for

torque wrench is used to tighten the bolts. An NG signal

conﬁrmation of the number of items tightened.In

will also be output to the lamp. In addition, because

addition to the wired counting method (QSPLS,

the tightening at part B can not be carried out until theetc.) using the signal from the limit switch,tightening at part A has been completed, the tightening

there is the wireless counting method (QSPFH,

work procedure will also be maintained. Using the thinetc.)client, it is possible to store and process data for each
body No.

CNA-4mk3

R-FH256▲▲

P410

Wired Link

P262

①Torque Wrench A

Wired Link

Wireless Link

⑤Patlite

Wireless Link

③Receiver Wired Link Output when NG▲

QLLS②Torque Wrench B
QSPFH

▲

A maximum of four torquewrenches can be connectedto the count checker.
In case of wireless, I/O-FH256
is required.

54

PLC

P258
P262

④Thin ClintPortion A

Portion B

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

ChapterMarking method

In addition to checking the number of units tightened,

A tightening conﬁrmation mark is applied when the tightening torque isthe actual tightening torque is shown, judgment is madeachieved. Previous systems had problems, such as the method where awhether or not the torque is within the standards, and data

sponge ﬁlled with ink was input in the socket, since simply setting theis stored. It is increasing the tightening reliability. Therewrench was enough to apply a mark and so it did not result in tighteningis the wired system (CSPD+CD5)and wireless system

conﬁrmation. In addition, for the method of making a mark using a marker(CSPFHD). This is also used as a backup for power tools.

pen, the making of the mark itself became work and it was possible to

Wired Link
Display▲

CSPFHD

make a mark even if tightening was not carried out, so this too did not
fulﬁll the requirements as a marking system.

P284

To solve this problem, there are marking torque wrenches available,
CD5

CSPD
▲

▲

Wireless Link

P416

P316

Wired Link

where a marker is activated to simultaneously prevent missed tightening
and erroneous operations only when the torque wrench is activatedand unfailingly applies the tightening torque; they are MPQL model forhexagonal bolts and CMQSP model for bolts with hexagonal holes.

Wired Link
Receiver
R-FHD256▲

Example of ID recognition from Thin Client(PC) using the CSPFHD receiver RS-232C output.

▲

CSPFHD

MPQL

▲

■

P284

P264

P284

Wireless Link

Wireless Link

▲

P284

CMQSP

P268

Tohnichi Tightening Assurance System▲

Receiver
R-FHD256

Wired Link▲

Wired Link

P60

Wired Link

Technical Data

55

4
Tightening Reliability

Monitoring method

Chapter

4-5

Tightening Reliability

Human Error（2）How to use torque tools
1. Precautions when selecting accessories！

● There is a danger that hexagonal sockets,(ballpoint type), universal joints, and ﬂexible joints

3. Method of applying force in manual torque tools
ONLY●

apply force in the direction marked ONLY .

(See How to Use on P.320)

may adversely aﬀect the tightening accuracy.

●Apply force at the eﬀective length line. (See How to Use on P.320)●There is a danger that extension bars and torsion bars

●Pull (or push)the force horizontally. (See How

may adversely aﬀect the durability of the torque tools.
●Use sockets, bits and adaptors that cometo Use on P.320)●Apply the force at right angles. (See How to Use on P.320)

within the range of assured strength.

●Do not apply the force with momentum.

●Use sockets and bits that match the screw size.

●Do not add your body weight when applying the force.

Depending on the accessories such as sockets andextension bars, there is a danger that the tightening
curacy and the tool durability may be lost. Take carewhen selecting the accessories.

●As soon as you hear the click sound or feel thatthe operation has ﬁnished, quickly remove the force.
●Do not repeat the same operation two or
three times on the same screw.

2. Inspections when starting work
●Conﬁrm the usage torque.

By carrying out operations using an unreasonable
posture, it will not be possible to use the torquetools correctly. Be sure to confirm the work
environment where the force is applied naturally.

For adjustable type tools, conﬁrm that the scalevalues are correctly set to the usage torque.
For preset type tools, confirm that the torquevalues described in the main unit are correctly set.
●Check whether or not there are scratches or rust on the main unit.
●Conﬁrm that there is no distortion of the main unit.

4. Cautions when using manual torque tools●Take care that dirt or water does notenter into the tool.
●Do not drop or allow the equipment to●Confirm that there are no parts missing. (Takecontact other objects.

particular care about damage to the ratchet part.)●Do not apply over-torque.

●Check whether there is wear on the socket and bit.

●Do not use for screw returning work.

Quickly detect degradation and damage to parts, and carry out
the tightening work using equipment that can be guaranteed.

●Use the tool with the extension handle.
(QLE2, CLE2)●Do not use the tool by extending thehandle part.
●Use the wrench with in the scale range.

56

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

Chapter4

5. Cautions for storage●When storing torque tools, reduce the graduation. (Adjustable types)

Tightening Reliability●Store in a location with low humidity
where there is little change in temperature.
●If the tool is not used for a long period of time, inspect it occasionally.

6. Cautions when using power torque tools●Adjust the usage pressure with a regulator (pressure
at hand).
●Ensure that the usage pressure does not vary.
●Use the stipulated air hose diameter item.
●Do not use a longer air hose than the required length.
●Take care that dirt or water does not enter into the equipment.
●When ﬁrst making the connection, connect after
blowing into the air hose.
●Apply oil (ISO VG32 (Turbine oil #90)).
●Use the three-point set (Regulator, ﬁlter, oiler).
●When the equipment will not be used for one week or longer,
insert oil directly into the cap (approximately 10 drops),
lightly rotate it one time, and then store it.
●Continue to pull the starting lever until the tightening has
been completed. (Automatic stop or automatic reversing)●Do not repeat the same operation two or
three times on the same screw.

Technical Data

57

Chapter

4-6

Tightening Reliability

Bolt Tightening Reliability and Bolts

Bolt tightening reliability and bolts
To ensure the bolt tightening reliability , first thereliability of the bolts themselves must be maintained.
The initial axial tension has to be controlled so thatthe force comes into the speciﬁed range determinedby the standardization or the design when the bolt istightened to the required torque. Since the torquecoeﬃcient changes due to the friction of the bearing
surface and the threaded parts, factors such as oil on
the threads, surface hardness, and surface treatment
should remain constant. As with high-tension bolts
for construction, the torque coefficient can be
Fcon▲measured by a tension meter to verify that the torqueP438

coeﬃcient is within the speciﬁed variation to further
improve the bolt tightening reliability. In this case, acertain number of samples will be required to ﬁnd thevariation of the torque coeﬃcient.
Bolted joints consist of bolts, nuts, and joint members.
Therefore, caution should be taken when adding oil tothe joint or carrying out surface treatment of the joint,
especially when wax-based oil or molybdenum-based
lubrication is used. The torque coeﬃcient will become
small and the initial axial tension will sharply increase.
The variations of joint face, parallelism, gaskets
in between, or paint will all have an affect on theclamping force. Galling or seating defects will
also prevent bolt reliability. Recently, an axial force
stabilizer (Fcon) has been developed that stabilizes
the torque coefficient to stabilize the axial force,
which is eﬀective in improving the above problems.

58

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

4-7

Tightening Reliability

Construction of a Tightening Reliability System
Chapter

Construction of a tightening reliability system
There are many obstructive factors for Bolt tightening

included. To maintain this reliability various methods have beenreliability as shown in P.47. To properly eliminate

designed, but their respective effects are different. (Table 4-2)

these factors, it is necessary to consider the total

More than one of these methods may be used in combination

system.

to reach the required reliability level, first seeking to eliminate
all the obstructive factors with the minimum expense and time.

The design, tightening operation, bolts, and the reliability in the

Even if an expensive system is adopted, if it misses any of theﬁeld all have to be equally improved in a balanced manner at eachrequirements the reliability will not be maintained. Standardization

step; otherwise, the errors in bolt tightening will not decrease.

of bolt tightening enables easy after-sales service. Even if theFirst of all, the suitability of the design and the preconditions has

special tightening method can successfully be employed in theto be veriﬁed. In the torque method, mutual consent is required

plant, the reliability will be lost if the same tightening cannot

regarding the tightening torque, tolerance, torque coeﬃcient andbe achieved by the ﬁeld service. The system of bolt tightening

dispersion width, tightening force in use and inspection methods,

reliability in the broad sense must include maintenance.

and must include people from design engineering, tightening

Since bolts easily generate a large clamping force, many bolts

operations and inspection.

are used in the assembly of products, but because there are

It is desirable that these are systemized by standardization.

many uncertain factors relating to bolt tightening, it inﬂuences

In order to construct a system of bolt tightening reliability ,the reliability of products and the entire system.

the elimination of machine error and human error has to be
Table 4-2. Methods of conﬁrming the reliability of tightening
Method1)100% retightening inspection2)Two-stage tightening (Double check)3)Sampling retightening inspection4)Periodical inspection of tightening tools5)Visual inspection by tightening operator6)Marking (Socket)7)Tightening completion by marking8)Tightening completion by counting9)Tightening torque control data OK-NG judgment10)Tightening torque control data preservation
11)Tightening torque monitoring (Independent)12)Tightening torque angle monitoring13)Clamping force measurement (Elongation, Ultrasonic)
14)Sampling torque coefficient testing15)Sampling product testing

Machine
error

Human
error

◎
◎
◎
◎
×
×
×
×
○
○
◎
○
◎
×
◎

◎
◎
×
×
○
○
◎
◎
◎
◎
◎
◎
◎
×
×

◎: Eﬀective, ○: Slightly eﬀective, x: Ineﬀective,［ ］: Visual inspection included

Technical Data

Bolt Reliability
Visual check
Non-Visual check

×
×
×
×
◎
×
×

◎
◎
○
×
×
○
◎
×
×
×
○
◎
◎
○
○

59

4
Tightening Reliability

ChapterChapter

4-8

Tightening Reliability

From Torque Control to Tightening Assurance System（1）Tohnichi Tightening Assurance System
Pneumatic Tightening DataManagement System

Pokayoke, Error Prooﬁng System
Pneumatic Torque Driverwith Limit Switch

Multiple Unit

P336

QLLS

P258

QSPCALS

▲

P234

CSPFH

▲

DAC

▲

P356

▲

▲

ME-TC

Remote Signal TypeTorque Wrench

Torque Wrenchwith Limit Switch

P262

AURLS
QSPCAFH

▲

▲

P326

MC-TC

P262

▲

P356
Wireless Link

RTDLS
▲

CD5
▲

P416

P182

Indicator

Wired Link

R-FH256▲

Wired Link

Wired Link

P262

ReceiverSoftwareNeed quotation

CNA-4mk3▲

P410

Tightening Count Control

Count Checker

Tool Management System for Pneumatic Tools
Periodic Calibration

Inspection Data Management System

Daily Inspection
Digital Torque Wrench

Torque Sensor

Rotary Peak Torque Meter

CEM3-G-BTS
▲

P282
▲

CTB2-G

P294

TCF+TP
▲

P398

ST2

ST2-BT
CEM3-G

P378

▲

P378

▲

Wired Link▲

Wired Link

P288

Wired Link
Wireless Link

SoftwareNeed quotation

60

Wired Link

P422

ＴＤＭＳＨＴ
Bluetooth
Adapter▲▲

P416 Indicator

TDMS
▲

CD5

Wireless Link

Wired Link

Bluetooth
Adapter

SoftwareNeed quotation

P422

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

Tohnichi Tightening Assurance System advices the users how to tighten bolts
properly and how to eliminate various mistakes which occur during bolt tightening
operations.

Chapter

Data Management System for Backup

Battery Operated
Torque Driver

Marking Torque
WrenchMarking Torque
Wrench with Sensor

P286

P286

CEM3-G-BTD
▲

▲

▲

▲

HATFH

CSPFHDSCSPD

MQSPFHDS

P264

Data Transfer
Torque Wrench

▲

MPQL

Torque Wrenchwith Sensor

P316

P282

▲

Wireless Link

P328

CSPFHD
Wireless Link

▲

P268

▲

CMQSP

P284

Wired Link
Wireless Link

Wireless Link

ReceiverWireless Link

MPQLFH▲▲

R-FHD256

Indicator

CD5▲

MPQLLS▲

Wired Link

P264

P284

P416

P264

Bluetooth
Adapter

SoftwareNeed quotation

Visual Check

Tool Management System for Manual Tools
Digital Torque Driver

Periodic Calibration
Torque Driver Tester

Daily Inspection

Torque Wrench Tester

Torque Wrench Checker

STC2-G▲P174
MEASUREMENT

13/8/9Model Name

Serial Number

esc

TOH000-A12345

TCC2-G

Accuracy (%)

N.m

2

3

4

5

20.00020.00020.00020.00020.00040.00040.00044.00060.00060.00060.00063.50060.00080.00080.00080.00080.00080.00080.000100.00100.00100.00100.0040.000100.0060.000

14:00

Click Type3.0

120.00040.00040.000

P366

TF

P374

SoftwareNeed quotation

Technical Data

LC3-G

▲

P368

1

Set Torque▲

DOTE3-G

▲

P364

▲

▲

TDT3-GCh

CEM100N3X15D

0.0000

Zero

Clear

MEMORY

P376

61

Tightening Reliability

4

Manual Tightening Data Management System

Chapter

4-8

Tightening Reliability

From Torque Control to Tightening Assurance System（2）System conﬁguration examples■ Pokayoke, Error-prooﬁng System ①
Control PC

Error-prooﬁng System
Case of click type Torque Wrench with wireless ID recognition function, FH
Tightening spot of each process is displayed on PC and thesystem provides with operational instructions by sound.
First of all, operator checks a tightening work with bar-code

User's Network
Process 1

Process 2

reader and works on tightening according to the instructions
from a PC. Besides, the tightening data is saved to a server
via a network. Traceability of tightening work is available.

Bar-Code
Process 1 PC
Reader

Process 2 PC
R-FH256▲

Receiver

Bar-Code
ReaderReceiverP262

Wireless Link

Wireless Link

▲

CSPFH

P262

■Pokayoke, Error-prooﬁng System ②
Wireless LAN base

The system is capable of managing data of actual applied torque

LAN Cable

Control PC

Error-prooﬁng + Monitoring System
Case of click type Torque Wrench with wireless data transfer function, FHD
value and preventing missed tightening.
An operator conducts tightening work according to instructions

Wireless Link

from PC. OK/NG judging is carried out based on the tightening
torque value of upper and lower limit. Results of the judgment are
saved to a server and traceability of tightening work is available.

Thin Client
LAN Cable

RS232C

Receiver
R-FHD256▲

P284

Wireless Link

CSPFHDS

▲

62

P286

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

■ Pokayoke, Error-prooﬁng System ③

applied torque value, marking bolt-head is also carried out.
It is very eﬀective to prevent and conﬁrm human error such as

Thin Client
LAN Cable

Wireless LAN station

missed tightening by visual check.
It is an advanced system to control the both number of bolts
to be tightened and actual applied torque value. All the data is
saved to a server and traceability of tightening work is available.

Receiver
R-FHD256▲

Wireless Link▲

MQSPFHDS

P284

P266

■ Pokayoke, Error-prooﬁng System ④
Error-prooﬁng + Monitoring System
Case of Digital Torque Wrench with wireless data transfer function, CEM3-G-BTD

Control PC

It is ideal for managing tightening data in cellproduction. Upper/Lower limit can be set through PC

LAN Cable

via duplex communication.
All the data is saved to a server and traceability oftightening work is available.

Wireless LAN base

Wireless Link

Slate PC

BluetoothⓇ
Duplex Communication▲

CEM3-G-BTD

Technical Data

P282

4

63

Tightening Reliability

Wireless LAN base
Wireless Link

RS232C

Chapter

In addition to preventing missed tightening and managing actual

LAN Cable

Control PC

Error-prooﬁng + Monitoring + Marking System
Case of Marking Torque Wrench with wireless data transfer function, MQSPFHDS

4-8

Tightening Reliability

From Torque Control to Tightening Assurance System
Nut runner torque checking can be conducted in high■Nut runner checking system
Case: Spintork / ST2-BT

accuracy and easy operation on a real-time basis by
ST2-BT with handy terminal. Data transfer is excutedby wireless communication.
Handy terminal, HT-S5, is excellent at compact mobility.

Nut Runner

Early detection is possible on the basis of information
complied by handy terminal.
Most errors can be avoided in adavance by statistical
ST2-BT

Extension Bar(Option)
POWER

ON
OFF

C

CLEAR
MODE

MD

work is available.

DOWN

Socket(Option)process of checked data. The tightening data is saved
to a server via a network and traceability of tightening

UP

ChapterSocket(Option)BluetoothⓇ▲

ST2-BT

P378

Handy Terminal HT-S5■Torque・Angle measurement system
Case: Digital torque and Angle Wrench / CTA2-BT

In angle-controlled bolt tightening, torque andangle are stimulously measured and displayedon handy terminal. Relations between torqueand angle can be graphycally-illustrated. Realtime anasysis is possible.

BluetoothⓇ
CTA2-BT▲64

Handy Terminal HT-S5

P272

TOHNICHI TORQUE HANDBOOK Vol.8

TECHNICAL DATA

■Torque wrench daily inspection system
Case: Torque Wrench Line Checker / LC3-G

Daily inspection of torque tools is coducted
before and after carrying out the work andChapter

keeps the tool problems to a minimum.
Data measured by LC3-G is saved to serverand errors can be avoided in advance by

RS232C

Control PC

maintenance can become possible.

P376■Torque wrench periodic calibration system
Case: Torque Wrench Tester / TF

This is the system to manage periodic calibration
data of torque driver and wrench by control PC.
The system gererates following functions by saving▲

TF

all the data to a server.

P374

・Tracking a full record from the beginning to the end
・Control of calibration cycle
・Alarm notiﬁcation to announce calibration period
・Issuing caribration certiﬁcate

RS232CUSB

RS232C▲

TDT3-G

RS232C Hub・Accuracy management by serial numbers and more...
Control PC

P364

Technical Data

4
Tightening Reliability

▲

LC3-G

statistical data. As a result, preventive

65