Clarke PRO425 User guide

¾" DRIVE TORQUE WRENCH

MODEL NO: PRO425

PART NO: 1700833

USER INSTRUCTIONS

ORIGINAL INSTRUCTIONS GC1025

INTRODUCTION

Thank you for purchasing this CLARKE Torque Wrench.

• Range 70-420 Nm

• Tool length 670 mm

• Case length 715 mm

• Tool and case weight 3.95 kg

This torque wrench is designed to tighten nuts with precision. It should NOT be used
for UNDOING nuts, as severe damage could occur. With correct use, this tool will
produce an accuracy of plus or minus 4%. You can hear and feel when the desired
torque setting has been reached. With careful and considerate use, the wrench will
give years of reliable service.

LIFETIME GUARANTEE

The lifetime guarantee covers defects in manufacture or materials during the lifetime
of the tool, however this guarantee does not apply to the ratchet mechanism. Please
keep your receipt which will be required as proof of purchase.This guarantee is invalid
if the product is found to have been abused or tampered with in any way, or not used
for it’s intended purpose. Faulty goods should be returned to their place of purchase,
no product can be returned to us without prior permission. This guarantee does not
effect your statutory rights.

OPERATING THE TORQUE WRENCH

TORQUE SETTING ADJUSTMENT

The main body is marked in both Newton/Metres (N/m), and Metre Kilograms (Mkg).
The barrel is marked with graduations, one graduation = 1N/m or 0.14 Mkg.

Example: To set the torque to 80N/m

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Parts & Service: 020 8988 7400 / E-mail: [email protected] or [email protected]

1. Ensure the locknut is loosened by turning it anti-clockwise. Turn the knurled
handle until the zero mark on the vertical scale is in line with the 70 mark on the
horizontal scale.

2. Continue to turn the knurled handle until the 10 mark is in line with the centre
line.

3. Tighten the lock nut to secure the setting.

METHOD OF USE

NOTE: Preferably, DO NOT use knuckle or universal joints, as these could result in

incorrect torque settings.

1. Place the square drive on to the socket or extension bar, perpendicular to the nut/
bolt to be tightened.

2. Gripping the knurled handle with the right hand, whilst steadying the 3/4” square
drive end with the left, gently but firmly, pull the handle (i.e. in a clockwise
direction) until a click is heard and a slight ‘break’ in the handle is felt. DO NOT
turn any further.

3. Apply even pressure throughout the operation. DO NOT jerk the torque wrench
when tightening a nut or bolt. This is a precise measuring instrument and should
be treated as such.

4. Release the wrench immediately the click is heard/felt.

5. Note that the ‘click’ becomes weaker with the lower torque settings.

CARE & MAINTENANCE

Each torque wrench has been lubricated before leaving the factory. If the wrench has
not been used for some time, operate it several times allowing the lubricant to re-coat
the internal working parts.

• After use, keep adjustment at lowest torque setting.

• DO NOT turn handle below lowest torque setting.

• Clean wrench by wiping. Never immerse in any type of cleaning fluid.

• The wrench may occasionally require servicing/recalibration in order to

ensure accurate readings, in which case, contact your CLARKE dealer.

CONVERSION FORMULAE

1kg cm = 13.887 oz/in 1Nm = 14.161 oz/in
1kg cm = 0.08677 lbf /in 1Nm = 8.8507 lbf/in
1kg/m = 7.233 lbf/ft 1Nm = 0.73756 lb/ft

1kg cm = 0.098 N/m 1kgm = 9.80665 N/m

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Parts & Service: 020 8988 7400 / E-mail: [email protected] or [email protected]

CONVERSION TABLES

Pound/
Feet
(lbf.ft)

5 0.69 6.78 10 7.38 1.02 1 9.81 7.23

10 1.38 13.56 20 14.75 2.04 2 19.61 14.47

15 2.07 20.34 30 22.13 3.06 3 29.42 21.70

20 2.76 27.12 40 29.50 4.08 4 39.23 28.93

25 3.46 33.90 50 36.88 5.10 5 36.17 36.17

30 4.15 40.68 60 44.26 6.12 6 58.84 43.40

35 4.84 47.46 70 51.63 7.14 7 68.65 50.63

40 5.53 54.24 80 59.01 8.16 8 78.46 47.87

45 6.22 61.02 90 66.38 9.18 9 88.26 65.10

50 6.91 67.80 100 73.76 10.20 10 98.07 72.33

55 7.60 74.58 110 81.14 11.22 11 107.88 79.57

60 8.29 81.36 120 88.51 12.24 12 117.68 86.80

65 8.98 88.14 130 95.89 13.26 13 127.49 94.03

Kilogram
Metres
kg/m

Newton
Metres
Nm

Newton
Metres
Nm

Pound/
Foot
(lbf.ft)

Kilogram
Metres
(kg/m)

Kilogram
Metres
kg/m

Newton
Metres
Nm

Pounds/
Feet
(lbf.ft)

70 9.67 94.92 140 103.26 14.28 14 137.30 101.27

75 10.37 101.70 150 110.64 15.30 15 147.11 108.50

80 11.06 108.48 160 118.02 16.32 16 156.91 115.74

85 11.75 115.26 170 125.39 17.34 17 166.72 122.97

90 12.44 122.04 180 132.77 18.36 18 176.53 130.20

95 13.13 128.82 190 140.14 19.38 19 186.33 137.43

100 13.82 135.60 200 147.52 20.40 20 196.14 144.67

105 14.51 142.38 210 154.90 21.42 21 205.95 151.90

110 15.20 149.16 220 162.27 22.44 22 215.75 159.13

115 15.89 155.94 230 169.65 23.46 23 225.37 166.37

120 16.58 162.72 240 177.02 24.48 24 235.37 173.60

125 17.28 169.50 250 184.40 25.50 25 245.18 180.84

130 17.97 176.28 260 191.78 26.52 26 254.98 188.08

135 18.66 183.06 270 199.15 27.54 27 264.79 195.30

140 19.35 189.84 280 206.53 28.56 28 274.60 202.54

145 20.04 196.62 290 213.91 29.58 29 284.41 209.77

150 20.73 203.40 300 221.29 30.60 30 294.22 217.00

155 21.42 210.18 310 228.67 31.62 31 304.03 224.23

160 22.11 216.96 320 236.05 32.64 32 313.84 231.46

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Parts & Service: 020 8988 7400 / E-mail: [email protected] or [email protected]