AMPS- Hardloc fastening systems 2019 V a1 isa

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Fasteners




inspired by a traditional gateway at a Shinto shrine in Osaka nearly 40
years ago, the self-locking Hard Lock Nut has become an international
success, offering improved safety and reduced costs by producing a nut
that never comes loose.

2



Applying the Wedge Principle with Two


The idea behind the Hard Lock
Nut is simple: it uses the wedge
principle to lock the nut into
place. Hammering a wedge be-

tween the nut and bolt is enough
to prevent loosening. But this is
not realistic in the real world,
since it would require workers to drive in a wedge every time
they screwed a nut and bolt together.


The solution was a similar wedge-like effect using

nuts alone. The solution he came up with was to use
two differently shaped nuts for each bolt: one con-
cave, the other convex. The concave nut (the upper

nut) has a perfectly spherical concavity, but the con-

vex nut (the lower nut) has a small eccentricity, with a
thin wedge on one side and a thick wedge on the oth-
er. When the concave nut is tightened over the convex

nut, the effect produced is the same as driving in a
wedge with a hammer.

The proven solution in threaded joints


Hardlock Nut was invented in the 1970’s, with the establishment of HARDLOCK
Industry Co., Ltd in 1974. As a receiver of many awards and establishing a
reputation in the railway industry for its renown self-lock ability, Hardlock
Products spread all over Japan to industries such as Manufacturing,
Construction, Aerospace and Mining... Hardlock has always took a moment to
reflect back on itself, improve Quality and maintain good customer relationships.
Hardlocks main objective is not to provide a good self-lock nut, but to provide a
product that will become the backing of society, a product that creates trust. The
hope to create a new culture based not on maintenance improvement but on
Equipment Design Improvement.

In 2012, Mining Company Vale started communications with Hardlock Brazil.
This led to trial testing of Hardlock Nut in the hopes that unplanned
maintenance could be reduced. At the current time, Weekly Maintenance of
Exciters and Motovibrators required the use of cranes to first remove the
housing and then finally check the nuts and bolts for signs of breakage/
loosening. After undergoing tests, In 2013 Hardlock Nut was recognized as the
ideal product to be used in Caue’s South Area Vibration Screens. The screen
manufacturer, Haver has also taken the initiative to install Hardlock Nut into the
Vibration Screens on assembly. Korean Screen Manufacturer ‘Mining
Machinery’ the first company to kick off Korea Sand Mining is another example
where HARDLOCK Nut was employed. Due to the previous problems with
breakage and loosening, Mining Machinery saw a huge improvement to Client
Satisfaction and Trust.

Vibration Screens Failure Mode Analysis:
70% of all Equipment Loss
1. Conveyors 70% of Screen Part Failures
2. Screens

3. Pumps 1. Vibration Motors
2. Main Motors 70% of Failure Modes
3. Screen Panels
4. Channels 1. Bolt Loosening / Failure
5. Exciters 2. Motor Burn Out
6. Cross Beams 3. Damaged Components
7. Cardan Shafts


※ According to Vale Caue’s loss profile analysis.
Problems related to loosening:
◆ Motor burn outs
◆ Exciter and Vibration Motor Bolt Failures
and Loosening
◆ Weekly Retorquing bolts for screen deck
◆ Weekly Retorquing bolts for Rubber Spring
◆ Monthly checks to check for cracking across
cross beams
Re-alignment of Cardan Shaft

Where are Hardlock Products used?

All of the above!
With the benefit of the following:
◆ Housing Securing Bolts Easier Removal and reinstallation
◆ Screen Panel Bolts.

The proven solution in threaded joints


Who should consider using Hardlock Products?
◆Ideal for companies looking to reduce unscheduled maintenance and
increase MTBF (Mean time between failures).
◆Reduce re-stocking and management of expendables while also reducing
cost.
◆ Looking for a low maintenance solution.
◆Searching for a fully tested reliable product, with focus on Quality and
customer satisfaction.

Why use Hardlock Products?
◆ Eliminating Fatigue Failure (Breakage)
◆No unplanned maintenance (+ extended preventative
maintenance)
◆ No special tooling
Hardlock Nut Huck Bolt
No Special tools necessary ( installation / removal ) ✔
Re-usage of nuts and bolts ✔
Rotational loosening prevention ✔ ✔

What’s the guarantee it won’t loosen?
Hardlock undergoes special testing to ensure that there are no problems on
installation. For example, to check nuts for self-locking ability:
◆ National Aerospace Standard – Vibration Test (NAS 3354)
◆ Junker Vibration Tests (ISO 16130)

The Junker Test Results and Assembly can be seen as below:
Junker Test Results – M12 Junker Test Assembly

Test Nut
Clamping force [kN] Glider Plate



Fixed Plate


Load Cell


Number of repeated cycles

Hardlock Products




Hardlock Nut Hardlock Nut Hardlock Hardlock Set
Basic Rim Bearing Nut Screw
(HLN-B) (HLN-R) (HLB) (HLS)
Visit Hardlocks main website for catalogues, and other technical details
https://www.hardlock.co.jp/en/products/
Please contact: [email protected] for further details.

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The HARDLOCK Nut is a two-piece locking
nut that is in use across many industries. By
using the HARDLOCK Nut, engineers can be
safe in the knowledge they are protecting ex-

pensive machinery and structures from the
effects of vibrations loosening in threaded
joints.




They can also reduce subsequent maintenance and inspection
costs. And unlike the majority of locking nuts available, the HARD-
LOCK Nut is reusable.




The HARDLOCK Bearing Nut is a lock-

nut for roller bearing use developed by
HARDLOCK Industry based on the

same wedge effect principle utilized in
the HARDLOCK Nut. Without making

any modifications to the specifications
of the machines or structures in which it used, the HARDLOCK

Bearing Nut provides a strong self-locking performance even un-

der the toughest environmental conditions.





The HARDLOCK Set Screw. In making com-
parisons between the HARDLOCK Set

Screw and conventional fixing screws, fac-

tors such as the need for post-installation
maintenance, costs stemming from subse-

quent loosening and inspecting difficult to reach places must be taken

into account. When using the HLS, there is no need to consider these
problems, which adds up to a significant reduction in overall costs.

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SAFETY IS PARAMOUNT


So is— Product reliability


Price



Reduction in maintenance



























We have greatly reduced the likelihood of an



accident by elimination of



Manual handling of heavy liners



Hot work using Hardloc fasteners

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Features

Leveraging the power of the wedge principle used in ancient Jap-
anese architecture, the HARDLOCK® Nut is the ultimate self-
locking nut which completely integrates the nut and the bolt.


Self-locking effect recognized by the world
The HARDLOCK® Nut passes United States NAS (National Aer-
ospace Standard) aviation standards.


Torque and Axial Force control
Control the axial force with proper torque wherever used.


Reusable
Made of all metal with little few wear surfaces, sustains

a powerful self-locking effect.

Easy and efficient

Can be easily installed with just one commercially available tool.


Economical
Reduced maintenance and labor add up to a significant savings
in overall costs.


Self-locking design
The HARDLOCK® Nut has a structure that prevents looseness

through the traditional Japanese principle of the wedge. To effec-
tively utilize the wedge structure, two nuts are used: (1) a convex

nut with an eccentrically formed boss, and (2) a perfectly circular
concave nut. When these nuts are fastened together, the wedge

principle mechanically creates a powerful locking effect trans-

verse to the bolt shaft. This powerful anti-loosening effect
achieved with the HARDLOCK® Nut wedge completely fuses the

bolt and nut. Once locked with this powerful force, the HARD-
LOCK® Nut is not susceptible to impulsive forces or shocks.

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Standard materials and coatings



Material Coating

Electrogalvanized (trivalent chromate)
Class 4/low-carbon steel (JIS SS400 equivalent)
Hot-dip galvanized (HDZ35)
Class 8/medium-carbon steel (JIS S45C) Manganese Phosphate coating

A2/stainless steel (JIS SUS304 or equivalent) Unplated/plain


Dimensions in milimeters


Overall
Pitch Convex nut Concave nut Width across flats Unit Weight
d e height
P m m1 s ℓ g
Nominal
Size Coarse Fine Basic Tolerance Basic Tolerance Basic Tolerance Approx. Approx. Approx.




0
M6 1.0 0.75 5 ±0.48 5 ±0.48 10 11.5 9.2 3.3
-0.6
0
M8 1.25 1.0 6.5 ±0.58 6.5 ±0.58 13 15 12 8.6
-0.7
0
M10 1.5 1.25 8 ±0.58 8 ±0.58 17 19.6 14.4 17.6
-0.7
0
M12 1.75 1.25 10 ±0.58 10 ±0.58 19 21.9 17.9 27.3
-0.8
0
M14 2.0 1.5 11 ±0.7 11 ±0.7 22 25.4 19.9 39
-0.8
0
M16 2.0 1.5 13 ±0.9 12 ±1.0 24 27.7 23.2 52.8
-0.8
0
M18 2.5 1.5 15 ±0.9 14 ±1.0 27 -0.8 31.2 26.7 80
0
M20 2.5 1.5 16 ±0.9 15 ±1.0 30 34.6 28.2 105
-0.8
0
M22 2.5 1.5 18 ±0.9 17 ±1.0 32 37.0 32.3 130
-1.0
M24 3.0 2.0 19 ±0.9 18 ±1.0 36 0 41.6 33.9 180
-1.0
0
M27 3.0 2.0 21 ±1.0 21 ±1.0 41 47.3 37.9 246
-1.0
0
M30 3.5 2.0 23 ±1.0 23 ±1.0 46 53.1 41.9 375
-1.0
0 0
M33 3.5 2.0 25 ±1.0 20 50 57.7 39.4 411
-1.5 -1.0
0 0
M36 4.0 3.0 28 ±1.0 21 55 63.5 41.9 532
-1.5 -1.2
0
0
M39 4.0 3.0 30 ±1.2 23 -1.5 60 -1.2 69.3 45.7 681
0 0
M42 4.5 4.0 33 ±1.2 25 65 75.0 50.2 892
-1.5 -1.2
0
0
M45 4.5 4.0 35 ±1.2 27 -1.5 70 -1.2 80.8 54.2 1,115
0 0
M48 5.0 4.0 37 ±1.2 29 75 86.5 58.2 1,393
-1.5 -1.2

Overall
Pitch Convex nut Concave nut Width across flats Unit Weight
d e height
P m m1 s ℓ g

Nominal
Size Coarse Fine Basic Tolerance Basic Tolerance Basic Tolerance Approx. Approx. Approx.




0 0
M52 5.0 4.0 41 ±1.2 31 80 92.4 63.7 1,708
-1.5 -1.2
0 0
M56 5.5 4.0 44 ±1.2 34 85 98.1 68.7 2,047
-1.5 -1.4
0 0
M64 50 ±1.5 38 95 110 77 2,795
-1.5 -1.4
0 0
M68 53 ±1.5 40 100 115 81.1 3,480
-1.7 -1.4
0
0
M72 57 ±1.5 42 -1.7 105 -1.4 121 85.1 3,910
0 0
M76 60 ±1.5 46 110 127 92.1 4,440
-1.7 -1.4
0 0
M80 63 ±1.5 48 115 133 97.1 5,070
-1.7 -1.4
0
0
M85 67 ±1.5 50 -1.7 120 -1.4 139 101.1 5,630
0 0
M90 71 ±1.5 54 130 150 109.1 7,340
-2.0 -1.6
0 0
M95 6.0 4.0 75 ±1.5 57 -2.0 135 -1.6 156 115.1 8,150
0 0
M100 79 ±1.5 60 145 167 121.1 10,140
-2.0 -1.6
0 0
M105 83 ±1.8 63 150 173 127.4 11,140
-2.0 -1.6
0 0
M110 87 ±1.8 65 155 179 131.4 12,000
-2.0 -1.6
0 0
M115 91 ±1.8 69 165 191 139.4 14,780
-2.0 -1.6
0
0
M120 95 ±1.8 72 -2.0 170 -1.6 196 145.4 16,050
0 0
M125 99 ±1.8 76 180 208 153.4 19,410
-2.0 -1.6
0 0
M130 103 ±1.8 78 185 214 157.4 20,650
-2.0 -1.6

• External dimensions according to JIS B1181 (2004)/ISO 4032 (width across flats only)
• Threads screw tolerance according to JIS B0209 (2001)/ISO 965 6H
• Specifications, including size, are subject to change without notice.

Tightening Torque Table Dimensions



Recommended
Reference tightening torque for convex nut (same as general hex nut) tightening torque for
*70% of the bolt yield point
the concave nut
Class 4 Class 8 A2/stainless steel
Nominal Pitch (SS400 or equivalent) (S45C) (JIS SUS304 or equivalent)
size
4.8 8.8 Common to all
(320 N/mm ) (640 N/mm ) A2-50 A2-70 materials (Min – Max)
2
2
Manganese
CR3 HDZ35 Plain
Phosphate coating




M8 1.25 – – – – – 9–13
M10 1.5 – – – – – 18–24
M12 1.75 – – – – – 27–39
M14 2.0 55 125 110 36 75 40–58
M16 2.0 – – – – – 70–100
M18 2.5 115 270 230 75 165 100–150
M20 2.5 – – – 110 230 120–200
M22 2.5 – – – 145 315 150–250
M24 3.0 – – – 185 400 160–300
M27 3.0 – – – 275 585 250–390
M30 3.5 – – – 370 790 270–440
M33 3.5 770 1,795 1,540 505 1,080 290–490
M36 4.0 990 2,305 1,975 650 1,390 340–590
M39 4.0 1,280 2,985 2,555 840 1,800 390–640
M42 4.5 1,580 3,690 3,160 1,035 2,225 440–690
M45 4.5 1,980 4,620 3,960 1,300 2,785 490–740
M48 5.0 2,370 5,530 4,740 1,555 3,335 540–780
M52 5.0 3,075 7,175 6,150 2,020 4,325 590–830
M56 5.5 3,820 8,915 7,640 2,505 5,370 640–880
M64 5,765 13,445 11,525 3,780 8,105 690–930
M68 6,980 16,287 13,960 4,581 9,816
M72 8,370 19,531 16,741 5,493 11,771
M76 9,931 23,172 19,862 6,517 13,965
M80 11,677 27,246 23,353 7,663 16,420
M85 14,131 32,973 28,263 9,274 19,872
M90 16,907 39,450 33,814 11,095 23,776
M95 6.0 20,023 46,721 40,047 13,140 28,158
Tighten about 1 turn after tightening manually
M100 23,503 54,841 47,006 15,424 33,051
M105 27,363 63,847 54,726 17,957 38,479
M110 31,623 73,787 63,246 20,753 44,470
M115 36,302 84,705 72,605 23,823 51,050
M120 41,425 96,658 82,850 27,185 57,254
M125 47,006 109,682 94,013 30,848 66,103
M130 53,067 123,823 106,134 34,825 74,625

• Stop tightening if full contact is reached between the convex and concave nuts before reaching the highest recommend torque.
• The reference tightening torque for the convex nut is calculated on the basis of a torque coefficient of 0.15.
• The tightening torque for the convex nut with HDZ35 is calculated on the basis of a torque coefficient of 0.35.
• For the tightening torque of the A2/stainless steel convex nut, refer to the strength classification of the bolt used.
• Because the proof load of the convex nut is the same as a general single nut, there is no unique torque value.
• The concave nut can be tightened until contact with the convex nut even if the tightening torque exceeds the recommended maximum value because the torque coefficient
varies depending on the surface roughness.
• For HDZ concave nuts, tighten 50% more than the recommended torque value due to the high torque coefficient.

HARDLOCK® Nut installation




Use a tightening tool
(spanner, torque wrench etc.)

to tighten the Convex Nut to
the appropriate torque for the

application.


The convex nut has the same

strength class as a regular

hexagon nut and can therefore be tightened to its maxi-

mum limit.














Install the
Concave

nut onto the
Convex nut

manually by hand until it no longer
turns (in other words, until prevailing

torque is generated). Make sure that there is a gap of more
than 1 thread pitch between the nuts.


If the gap is less than 1 pitch, there may be a chance that

sufficient locking effect will not be produced so please re-
frain from using HARDLOCK® Nut with the bolt.


(The same conditions apply for reuse.)

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Use a torque wrench to tighten the Concave nut with
the recommended torque set by
HARDLOCK Industry Co., Ltd.


If it is difficult to manage the tighten-
ing torque of the Concave nut,

please use “one-sided contact” as
a guide for ensuring locking power.






When tightening the Concave nut

on to the Convex nut, one side of
the nuts will first come into contact,
which gives an indication of suffi-
cient locking effect (The Concave

nut will slightly incline after the con-
tact between the protrusion and the
recess.). When one-sided contact is
achieved, the tightening torque rapidly increases.


By applying additional torque , the nuts will come into full contact.
This state produces the ulti-
mate locking effect of the
HARDLOCK® Nut, but fur-

ther tightening may cause the
breakage of bolt threads.


It is recommended to stop
tightening the concave nut
when the nuts come into full
contact even though the ap-
plying torque is less than the maximum of recommended tightening

torque.


Even after correctly tightening the Concave nut with the torque within
the range of recommended tightening torque, there may remain
a gap between the nuts due to the tolerance of bolt diameter.


Even in this condition, sufficient locking effect is secured but

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HARDLOCK NUT INTRODUCTION



FEATURES OF HARDLOCK NUT
•0• Reusable without reduction in performance !
•g• Full torque management and completely fastened even with ZERO (D) clamp load !
6 Available in various materials and surface treatments tailored to the environment !
'0• No special tools required for installation !

LOCKING MECHANISM
HARDLOCK NUT consists of two nuts, the first lxit "Convex
Nut" @(clamping nut) kas a tmncated protrusion arranged
off-cemeron the upper surface.
The second nut "Concave Nut" (locking nut) is designed
with a concentric conical recess for locking the two
By tightening the concave nut omo the convex nut. a strong
perpend'icuIar load will be applied to the bolt from both sides,
PROVED SUPERIOR IN A VARIETY OF LOOSENING TESTS
1) Accelerated viblBtion test confDrlT\ing IO NAS 3350/3354 (National Aerospace Standard)
To determine the capability of fasteners to withstand accelerated vibration condltion.













HARDLOCK SET SCREW












■ IVIAINTENANCE-FREE WITH EXTRAORDINARY LOCKING PERFORMANCE














Used to fix core pins in casting/ molding dies and to lock shaft collars.

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TECHNICAL DATA





Self-Locking Nut































Industry Co., Ltd.

HARDLOCK Nut Features







1.1 SELF-LOCKING EFFECT RECOGNIZED BY THE WORLD



1.1.1 JUNKER VIBRATION TEST (LOOSENING UNDER TRANSVERSE CYCLIC LOADS TEST)


The representative tests which are used to loosen jointed bolts/threaded fasteners by

s
subjecting transverse repeated loadings and impact to the bolt’ axis in perpendicular direction are:
the German Industrial Standards: DIN65151 Junker-type screw loosening test (Junker Vibration Test), and
the National Aerospace Standards: NAS3350 / 3354 test.


























Various Nuts Comparison Test Results



20



15

Bolt Preload [kN] 10






5




0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500








3 Industry Co., Ltd.

1.1.2 PRINCIPLES OF LOOSENING AND THE LOCKING FUNCTION OF HARDLOCK NUT


External Force
Bolt & Nut Rotational
Loosening Direction
Sliding



(1) Bolt & Nut fastened state (2)When an external force (3)The Bolt & Nut slides in the
direction of the lead.
is applied, sliding occurs in
the threaded portion and
the nuts bearing surface. Rotation loosening occurs

Fixed Plate

①Movable plate`s left
Movable directional limit
plate


Elastic Torsion of the bolt axis

②Sliding is generated in the threaded
portion of the bolts right directional
limit. Bolt is rotating in the loosening
direction.

Nuts rotation loosening

③Movable plate’ s right directional limit.
Sliding occurs in the nuts bearing surface.
Elastic torsion of the bolt is released.
The nut starts rotating in the loosening direction.



During bending momentum there is a higher
chance of loosening!





Source of the
locking effect !




a:Eccentricity

Since locking occurs here, the effect of the friction in the bearing surface is reduced.




Industry Co., Ltd. 4

1.1.3 OTHER TEST CONDITIONS FOR LOOSENING UNDER TRANSVERSE CYCLIC LOADS TEST



(1) Junker Test Results at Different Amplitudes


Upper plate moves back and forth EUT

・Bolts: Hexagon M12 Bolt, Strength Class 4.8
・Nuts: Hex M12 Nut, HLN M12
Strength Class 4 (JIS SS400 Equiv.) Test
Conditions
・Initial Preload: 8.1kN, 30% of Bolts Yield Point
・Test Level: Amplitude±0.35、0.5、0.75mm
±
±


10





Bolt Preload [kN]
Hex Nut（±0.35、±0.5、±0.75）



◇ The EUTs was marked before initializing the test to verify loosening ratio
1
Test Level : Amplitude ±0.35, Before & After pictures of the EUTs


0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
By inspecting the
markings, we can
conclude that the
HARDLOCK Nut
HLN did not work
loose.






By inspecting the
markings on the
hex nut, we can
conclude that
loosening did
occur.











Hex Nut













5 Industry Co., Ltd.

(2) Junker Test Results at different Initial Preload

EUT


・Bolts: Hexagon M12 Bolt, Strength Class 4.8
Bolt Preload
・Nuts: Hex M12 Nut, HLN M12
Strength Class 4 (JIS SS400 Equiv.) Test
Condition
20
・Amplitude：±0.35mm
・Test Level : 70%, 50%, 30% of Preload Yield Point
15



Bolt Preload [kN] 10






500 1000 1500 0 500 1000 1500 0 500 1000 1500


◇The EUTs was marked before initializing the test to verify loosening ratio

Test Level : Preload 50% of Yield Point, Before & After Pictures of EUTs


By inspecting the
markings, we can
conclude that the
HARDLOCK Nut
HLN did not work
loose.
























Hex Nut











Industry Co., Ltd. 6

1.2 NAS3350/3354 TEST



NAS: (NATIONAL AEROSPACE STANDARD)3350/3354 is an accelerated vibration test which is
referred to as the NAS test.
The picture below is the schematics of the NAS3354









Frame




At HARDLOCK Industry Co., Ltd. we call our NAS Test for 「 Accelerated Vibration Test Conforming to
.
NAS 3350/3354」The reason why we call it "Conforming to" is because the NAS Test we perform and the

original NAS3350 differs as seen below.
１．All test nuts are specified in inch size. ２．intered for 6
S
hours in assembled condition. ３．ightened by a specified
T
torque.
Below is the specified preload table for the NAS3350 shown in Inches, we converted/ recalculated it to
N・m and added it to the table
One thing not mentioned above is that the material of the nuts and bolts used in the National Aerospace
Standard (US) are made of heat-resistant alloys, the lubricant used is also heat-resistant, various criteria
needs to be followed. To correctly perform the NAS Test you need to follow the above criteria.

Size Maximum Tightening Torque
Pre-Sintering (Room Temp.) Post-Sintering (Room Temp.)
Meter Inch
N・m INCH・LBS N・m INCH・LBS
No.10 2.0 18 4.1 36
M5 2.2 4.3
M6 3.1 6.2
1/4 3.4 30 6.8 60
5/16 6.8 60 13.6 120
M8 6.9 13.8
3/8 9.0 80 18.1 160
M10 9.7 19.4
7/16 11.3 100 22.6 200
M12 14.5 28.9
1/2 17.0 150 33.9 300
M14 21.6 43.2
9/16 22.6 200 45.2 400
5/8 33.9 300 67.8 600
M16 34.3 68.7
















7 Industry Co., Ltd.

1.2.1 TEST METHOD



(1) Attach and detach the nut 4 times before sintering. By the fifth time, attach the nut and start sintering. (2)Sinter in the
F
F
assembled condition for 6 hours in tempratures at 800°+25°425±2 ℃) or 450°+25°230±2 ℃) (3)After Baking, substantially apply
(
F
(
F
SAE20 oil to the bolt, then tighten to the recommended preload. (4)Mark the bolt, nut and washer with a line
before initializing the test.
(5) Test conditions are set to a 1750～1800c.p.m vibration frequency. However, if the specimen
rotates 360°efore 30000 cycles the test will be terminated.
b
(30000 cycles are approximately 17 minutes)
(6) After testing, the speciemen shall be examined under 10X magnification for cracks or broken segments.
※During this test No.(6) was not performed.
Test Description
4 different types of materials and 4 different types of nuts were tested. Material(4 kinds)×Test
nuts(4 kinds) ＝ 16 Total.

Test Conditions EUT
Bolt : Hexagon Bolt M16 x 70, Unplated
Nuts : Hex Nut (Type 1), Hex Jam Nut (Type 3), Unplated HARDLOCK
Nut M16x2.0, Unplated
Material : S45C(H), SCM435, C267 Alloy, Ti-6AI-4V (Titanium Alloy) Tolerance Grade
: S45C(H), SCM435 = 6H/6g. C276 Allot, Ti-6AI-4V = 4H/4h. Sinter Temp : S45C(H),
SCM435 = 230±２°
C
C274 Alloy, Ti-8AI-4V = ４ ２ ５±２°
C

Test Nut
HLN : HARDLOCK Nut, SN+SW : Hex Nut (Type 1) + Spring Washer, DN : Hex
Nut (Type 1) + Hex Nut (Type 3), SN : Hex Nut (Type 1)


Tightening Method
HLN : Before sintering, attach and detach the Convex Nut 4 times, then do the same with the Concave Nut. DN : Before
sintering, attach and detach the Lower Nut 4 times, then do the same with the Upper Nut.
SN + SW, SN : Attach and detach according to test method


Test Method Description *The EUT's in the picture are of Ti-6AI-4V material
(1) Before sintering, the EUT is tightened with a torque of 34.3 Nm



































Industry Co., Ltd. 8

C
(2) Sinter for 6 hours at 425 ± 2° then let it cool of naturally



















*After sintering, the effect of the SW is reduced immensely
(3) After substantially applying SAE20 oil to the bolt, the sintered (4) Mark the EUT and initialize the test
nut is tightened with a torque of 68.7 Nm



Tighten the Convec Nut Tighten the Concave Nut














1.2.2 TEST RESULTS

Material S45C(H) SCM435 C276 Alloy Ti-6Al-4V
Vibration time Vibration time Vibration time Vibration time
No. EVAL. EVAL. EVAL. EVAL.
Cycles Cycles Cycles Cycles
20 sec. 15 sec. 10 sec. 45 sec.
1 × × × ×
593 445 297 1335
SN
10 sec. 15 sec. 10 sec. 15 sec.
2 × × × ×
297 445 297 445
30 sec. 30 sec. 10 sec. 30 sec.
1 890 × 890 × 297 × 890 ×
SN+S
W 2 10 sec. × 45 sec. × 10 sec. × 40 sec. ×
297 1335 297 1187
1 sec. 1 sec. 15 sec. 3 sec.
1 1780 × 1780 × 445 × 5340 ×
WN
20 sec. 45 sec. 20 sec. 5 sec.
2 × × × ×
593 1335 593 8900
Approx.17 Min. Approx.17 Min. Approx.17 Min. Approx.17 Min.
1 30000 ○ 30000 ○ 30000 ○ 30000 ○
HLN
Approx.17 Min. Approx.17 Min. Approx.17 Min. Approx.17 Min.
2 ○ ○ ○ ○
30000 30000 30000 30000
By looking at the test results we can conclude that no matter what kind of
material, the HARDLOCK Nut will not come loose.



9 Industry Co., Ltd.

1.3 LOOSENING UNDER TRANSVERSE CYCLIC LOADS TEST



1.3.1 OVERVIEW OF THE LOOSENING UNDER TRANSVERSE CYCLIC LOADS TEST



In addition to the perpendicular direction of the bolts axis, consider the cyclic loads in the transverse
direction. During the transverse cyclic load test, rotational loosening will occur when the cyclic loads
are more than twice of the preload.

∴ W / F 0 ＝ C, when C ≧ 2 Loosening rotation occurs.
( W: Applied Load, F₀: Initial Preload )
As seen in the diagram below, the bolt and nut is tightened to the jigs lower part and applied to cyclic
loads.
By applying cyclic loads, you can observe whether rotational loosening occurs by measuring the axial
force of the bolt and nut.

Test Frequency
Cyclic Load：1Hz Jig Top is Fixed
m


Test Diagram


：Hex Bolt
M12×70, Strength Class 4.8
Surface Treatment : Trivalent
Chromate


Enlargement Up/Down
Amplitude


：HARDLOCK Nut
M12×1.75, Strength Class 4
Surface Treatment : Trivalent
Chromate
Jig Bottom
Vibrates Hex Nut (Class 1) M12×1.75,
Strength Class 4 Surface Treatment
: Trivalent Chromate
Hex Nut (Class 3) M12×1.75,
Strength Class 4 Surface Treatment
: Trivalent Chromate





Industry Co., Ltd. 10

Test Conditions
(1)Preload F₀
Bolt yield preload Fy20％ 、 70％ 2 sets Fy=
340 × 84.3

= 28662 (N)
①Fy 20％ = 5732 (N)
②Fy 70％ =20063 (N)


(2) Cyclic Load W
Bolt yield preload Fy50％ 、80％ 2 sets
③Fy 50％ = 14331 (N)
④Fy 80％ =22930 (N)
②－④ ①－③ ①－④
(3) Applied load ・Preload combination

Condition / Combination Preload F0 Cyclic Loads W Remarks
②-④ 20063 N 22930 N No Loosening
①-③ 5732 N 14331 N Chance of Loosening
①-④ 5732 N 22930 N Loosening


Test Nuts
HLN ：HARDLOCK Nut Standard Rim Type
WN ：Hex Nut (Type 1) + Hex Jam Nut (Type 3) SN+SW
：Hex Nut (Type 1) + Spring Washer
SN ：Hex Nut (Type 1)


The nuts were all tested in the different conditions.
The following is a summary of the results.

Test Results

Condition Specimen Number of Preload Remaining Clamp Load Preload Remaining
No. Cycles Fo (kN) Fz (kN) Reduction Fo- Clamp Load
Fz (kN)
HLN 5000 19.25 18.42 0.83 96
②－ WN 5000 19.95 17.01 2.94 85
④ SW 5000 19.85 15.79 4.06 80
SN 5000 20.07 15.15 4.92 75
HLN 5000 5.73 4.99 0.74 87
①－ WN 5000 5.77 3.11 2.67 54
③ SW 5000 5.73 0.00 5.73 0
SN 5000 5.75 0.00 5.75 0
HLN 5000 5.67 4.75 0.92 84
①－ WN 5000 5.96 0.00 5.96 0
④ SW 2500 5.70 0.00 5.70 0
SN 1100 5.78 0.00 5.78 0










11 Industry Co., Ltd.

1.3.2 TEST RESULTS

②－④/Combination


30


25
HARDLOCK Nu t
20
Bolt Preload [kN] 10 S S +S W


15




5 N N W N

0
2000
0 4000 6000
Numbers of Cycles [N］


30 ①－③/Combination
[Chance of Loosening]
25
Cyclic Load 14.3 kN
Bolt Preload [kN] 15
20

S SN+S W HARDLOCK Nut

10 N W N
5


0
2000
0 4000 6000
Numbers of Cycles [N］

30 ①－④/Combination

[Loosening}
25

20
Bolt Preload [kN] S SN+S W
15




10 N W N

5

0
2000
0 4000 6000
Numbers of Cycles [N］
As seen in the test results above, if the bolts and nuts are tightened with sufficient preload, it is difficult for
rotational loosenign to occur.
However, if for some reason, the preload gets reduced, as long as the Hardlock Concave Nut is
tightened, it is difficult for a loosening rotatio to occur.




Industry Co., Ltd. 12

2 ENABLES TORQUE AND CLAMP LOAD CONTROL



TIGHTENING TEST RESULTS



The basics of how to use the HARDLOCK Nut, after applying a clamp load/preload to the Convex Nut, use the
Concave Nut to lock them together. The Convex Nut should be tightened with the appropriate torque required for
the application, the Concave Nut however, shall be installed with the recommended torque set by HARDLOCK
Industry Co., Ltd.
Below you can see the tightening test results of the HARDLOCK Nut and standard double nuts.

Graph (1) Tightening HLN Convex Nut


45

40

Bolt Preload [kN] 35

30

25

20

15

10

5 Graph (2) Tightening HLN Concave Nut
50
0
5 0 10 20 30 40

Torque [N・m]














45
Bolt Preload [kN] 35 adhesion
40


30
25

20
15
10

5
0
0 10 20 30 40 50
Torque [N・m]


13 Industry Co., Ltd.

Test Conditions EUT
Bolt : M12×70, Strenght Class 4.8, Surface treatment: Trivalent chromate Nut :
Hexagon Nut (Type 1), Hexagon Nut (Type 3), HLN
Strenght Class 4, Surface Treatment : Trivalent Chromate Lubricant : Paste

Double Nut Tightening Method
Upper Nuts correct tightening Method : Tighten the lower nut, then upper nut while fixing the lower nut.
Tighten the lower nut to 40% of the yield point and the upper nut to
80% of the yield point

Graph (3) Double nut (Lower) : Hexagon nut (Type 1) Tightening Method




45

40
Bolt Preload [kN] 35
30
25

20
15
10
5 Graph (4) Double nut (upper) : Hexagon nut (Type 3) Tightening Method
0
0 10 20 30 40
Torque [N・m]















By tightening the upper nut,
the preload is increased
immensely
Bolt Preload [kN] 40
45

35
30
25
20
15
10
5
0
0 10 20 30 40 50
Torque [N・m]






Industry Co., Ltd. 14

Graph (5) HARDLOCK Convex Nut : Tightening until damage on the bolts threads


















Bolt Preload [kN]







25

15
10



10














Bolt Preload [kN]








25


15
10


10





15 Industry Co., Ltd.

By observing changes in Torque and Preload when tightening the Concave Nut in Graph (2), it is seen that
there is no significant change in Clamp Load when tightening within the Recommended Torque Range.
Accordingly, in case of HARDLOCK Nuts, the user can control the Clamp Load by tightening the Concave Nut within
the Recommended Torque Range after tightening the Convex Nut to the appropriate torque required for each
individual application.
On the other hand, looking at Graph (4) for double nuts, the preload is increased when tightening the upper nut. In
other words, in practice it is said to be difficult to control the clamp load when utilizing dubbel nuts.
Looking at Graph (5), you can see that the Recommended Torque Range for the Concave Nut is about half of the
Thread Shear Torque. Therefore, as long as the HARDLOCK Nuts are installed correctly, there will be no shear
on the threads when tightening the Concave Nut.
With this in mind, you can see that the HARDLOCK Nut is capable of bolt clamp load control, and that there is no
risk reaching the Bolts Yield Point even if slightly tightening the Concave Nut beyond the Recommended Torque
Range.

Reference Case
In general, when comparing the breaking load of simply pulling the threads, and when twisting the threads
by tightening (torsion applied tensile breaking load), the twisting is said to be about 85% of the bolts breaking
load.
The breaking load for Double Nuts and HARDLOCK Nuts for this Destruction Test is the same, around 30kN.
As seen in the graph below, the Hex Jam Nut's (Type 3) threads got damaged after applying approximately 35kN.
85% of 35kN is around 30kN so the below Thread Destruction Test Results can be said to be accurate.







Load [kN]


40

30



Test Conditions

Bolt : M12x70 Strenght Class 4.8, Surface Treatment: Trivalent Chromate (Same conditions as present test) Nut : Hexagon Jam Nut
(Type 3), Strenght Class 4, Surface Treatment: Trivalent Chromate(Same conditions as present test)



12
0 2 4 10 Industry Co., Ltd. 16

3 POSSIBLE TO REUSE




One of the feature of the HARDLOCK products is that they can be re-used several times.
Performance after repeated usage and information relating to torque and clamp load is seen below.

Test Conditions EUT
Bolt : M12x70 Strenght Class 4.8, Surface Treatment: Trivalent Chromate
Nut : HLN, Strenght Class 4, Surface Treatment: Trivalent Chromate

1st Tightening



25


20


15

Bolt Preload [kN]

10





2nd & 11th Tightening
10 20 50















25

20
Bolt Preload [kN] 15




10






10 20 10 20





17 Industry Co., Ltd.

Test Method
(1) Tighten the HLN and commence the tightening test.
(2) Conduct the Junker test to confirm self-locking results.
(3) After conducting the Junker test, conduct the tightening test.
(4) Attaching and detaching 8 times and perform re-tightening test.
(5) Repeat (1)～(4), Reapeat (2) until you have attatched and detatchedthe nut 51times.


Tightening Method
Tighten Convex Nut to 70% of the yield point Tighten
Concave Nut until one-sided adhesion


Junker Test Result after 1st Tightening


25


20


15

Bolt Preload [kN]
10



Junker Test Result after 11th Tightening


0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500







25


20


Bolt Preload [kN] 15



10







0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500






Industry Co., Ltd. 18

Test Schematics

Tightening ×1 Junker Tightening Junker ×5
Test Test Test ×10 Test
1st Tightening

The Junker Test was conducted 6 times and the nuts where tightened a total of 51 times. Below, we show 10
before and after test results of the tightening test and before and after test results of the Junker test



12th & 21st Tightening





25


20

15
Bolt Preload [kN] 22nd & 31st Tightening


10






10 20 30 40 0 10 20 30 40
Torque [N・m] Torque [N・m]












25


20
Bolt Preload [kN] 15




10





10 20 30 40 0 10 20 30 40
Torque [N・m]
Torque [N・m] Torque [N・m]
Torque [N・m]






19 Industry Co., Ltd.

Junker Test Results
・Amplitude : ±0.35mm
・Preload : 70% of Yield Point
・Vibration Cycles : 1500 Cycles
When conducting the Junker test, lubricant is applied. This is to avoid residual clamp load due to factors
other than the self-locking function and to prevent thread seizure. For example, if there is thread seizure,
dents on the bolt or if the nut gets caught on the roughness of the bearing surface, rotational loosening may not
occur. By applying a lubricant to eliminate these influences, it is possible to measure the pure sef-locking
performance.

Junker Test Results after 21st Tightening




25


20


15
Bolt Preload [kN]

10
Junker Test Results after 31st Tightening




0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500








25


20

Bolt Preload [kN] 15




10







0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500







Industry Co., Ltd. 20

Junker Test Results
・Amplitude : ±0.35mm
・Preload : 70% of Yield Point
・Vibration Cycles : 1500 Cycles
When conducting the Junker test, lubricant is applied. This is to avoid residual clamp load due to factors
other than the self-locking function and to prevent thread seizure. For example, if there is thread seizure,
dents on the bolt or if the nut gets caught on the roughness of the bearing surface, rotational loosening may not
occur. By applying a lubricant to eliminate these influences, it is possible to measure the pure sef-locking
performance.



32nd & 41st Tightening



25

20


15
Bolt Preload [kN]
10

42nd & 51st Tightening



10 20 30 40 0 10 20 30 40
Torque [N・m] Torque [N・m]









25


20

Bolt Preload [kN] 15



10







10 20 30 40 0 10 20 30 40
Torque [N・m] Torque [N・m]










21 Industry Co., Ltd.

By looking at the results of the reapted attaching and detaching test so far, you can see that there are no
major changes in tightening characteristics of the HARDLOCK Nut even after repeated usage.
Take notice to the change in clamp load when tightening the Concave Nut. When tightening the Concave
nut you can see that there is almost no change in the preload.




Junker Test Results after 41st Tightening




25


20



15

Bolt Preload [kN] Junker Test Results after 51st Tightening
10








0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500












25



20
Bolt Preload [kN] 15




10







0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500









Industry Co., Ltd. 22