Makita BTW151 Manual

Models No.
Description
PRODUCT
TECHNICAL INFORMATION
CONCEPTION AND MAIN APPLICATIONS
Specification
Standard equipment
Optional accessories
< Note > The standard equipment for the tool shown may differ from country to country.
P 1 / 8
BTW151
14.4V Cordless Impact Wrench
Because of the over-tightening, it was a problem to employ
impact wrench in the working field where the even controlled
fastening torque is required.
However, the above mentioned BTW151 has solved this problem
with the "BPM preselection system".
Of course, BTW151 is equipped with newly developed battery
system as Model BTW150.
Below listed standard type model is only available.
BTW151BSA Ni-MH
BH1420 / 14.4V / 2.0Ah
Model No. Battery Charger
DC14SA
Plastic
case
Yes
Dimensions : mm ( " )
Width ( W )
Height ( H )
Length ( L ) 193 (7-5/8)
*253 (10)
78 (3-1/16)
*253 (10) is the height with battery BH1420.
W
H
L
14.4
0 - 2,300
0 - 3,000
No load speed (min-1=rpm)
Max. fastening torque
Electric brake
Variable speed control switch
Reverse switch
Voltage (V)
Capacities
Impact per minute (min-1=bpm)
Driving shank : mm ( " )
Net weight: kg (lbs)
High Tensile bolt
Machine screw
Self drilling screw
Course thread
Standard bolt
Square 12.7 (1/2)
150N.m 1,530Kgf.cm 1,330in.lbs
Yes
Yes
Yes
1.9 (4.3) including battery BH1420
BTW151
Model No.
M10 - M16 (3/8 - 5/8)
M8 - M12 (5/16 - 1/2)
* Socket 19-38 ................................... 1 pc.
* Pin 4 ................................................ 1 pc.
* O ring 24 ......................................... 1 pc. (Except North American market)
* Plastic case ....................................... 1 pc. (only for Model BTW151BSA)
* Various socket
* Battery BH1420 (2.0Ah)
* Battery BH1433 (3.3Ah)
* Charger DC14SA

Features and benefits P 2 / 8
BPM. pre-selection system
The machine stops automatically, when the equipped
bpm. sensor perceives the pre-selected bpm.
And the over tightening can be avoided with
BPM. pre-selection system.
Consequently, Mod.BTW151 is suitable for fastening work
in the section where the fastening torque is directed in advance.
Bottom view of grip end
(View from terminal side)
193mm
Compact overall length : only 193 mm Only 1.9 Kg (4.3 lbs) including battery
BH1420
Newly developed 24V Ni-MH batteries
(BH1420 / 2.0 Ah and BH1433 / 3.3 Ah)
can be used for Mod.BTW151.
Long life DC motor with the
following features
* 2 ball bearings
* Replaceable armature
* Externally accessible brush
Sturdy Aluminum
hammer case
Palm fitly soft and slim grip with
ergonomically shape for comfortable
gripping
12.7mm (1/2") square drive
Push button for reversing
Variable speed control switch
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
How to pre-select BPM.
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
BPM. pre-select dial
The first digit
The second digit
(The alphabet means
working mode for
special employment.)
BPM. pre-select dial is located in the grip end
as illustrated above,
and it can be found easily, when the battery
is taken off.
BPM. can be set by turning the dial
with flat head screwdriver so that the dial's arrow
align with the numbers or alphabet indicated on the
machine's body.
The figures mean as illustrated in Fig.A - Fig.C.
See next page.
Bumper to protect the
surface of materials
from scratch
Model BTW151

Features and benefits P 3 / 8
If you want 196 bpm., align the pre-setting dial of the second
digit with 9 and the same of the first digit with 8 as illustrated
in Fig.A. Namely, 98 x 2 = 196 bpm.
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
The second digit The first digit
If you want more than 200 BPM., align the both
pre-setting dials with 9 as illustrated in Fig. C.
In this case, Mod.BTW151 is used as an normal
cordless impact driver with 0 - 3,000 bpm.
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
The second digit The first digit
If you want 104 bpm., align the pre-setting dial
of the second digit with 5 and the same of
the first digit with 2 as illustrated
in Fig.B. Namely, 52 x 2 = 104 bpm.
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
The second digit The first digit
Fig.A
Fig.C
Fig.B
Indications and functions
0 - 9 1 - 8
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
99
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
00
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
Dial pre-selection Clockwise rotation Anti-clockwise rotation Purpose
The machine stops automatically,
when its sensor perceives the
pre-selected bpm which is
equivalent to double of the figures
selected with dial.
The machine starts or stops with
operation of the trigger switch.
The machine starts or stops with
operation of the trigger switch.
Mode of reverse switch
The fastening work
of bolts for which
the bpm. control is
required.
The fastening work
of bolts for which
more than 200 bpm.
is required, or
bpm. control is not
required.
The machine does not start
in spite of operation of switch
trigger.
The machine starts or stops with
operation of the trigger switch.
Fastening of bolts
The second
digit
The first
digit
The second
digit
The first
digit
The second
digit
The first
digit

Features and benefits P 4 / 8
Indications and functions
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
A
BSelect any of
0 - 9
Select any of
0 - 9
Select any of
0 - 9
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
C
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
Special purpose
Dial pre-selection Clockwise rotation Anti-clockwise rotation
Mode of reverse switch
If the dial of second digit is set on "A", the machine does not
start in spite of pulling trigger switch.
Purpose
The machine stops after the
first blow is perceived,
depending on the pre-selected
figures of the first digit.
For instance,
0 : Stop at one
1 : Stop 0.1 sec. later
2 : Stop 0.2 sec. later
9 : Stop 0.9 sec. later
The machine starts or stops
with operation of the trigger
switch.
Preliminary fastening
of bolts
The machine starts or stops
with operation of the trigger
switch.
Loosening of bolts
Depending on the pre-selected
figures of the first digit,
the machine stops when its blow
is not perceived.
For instance,
0 : Stop at one
1 : Stop 0.1 sec. later
2 : Stop 0.2 sec. later
9 : Stop 0.9 sec. later
The second
digit
The first
digit
The second
digit
The first
digit
The second
digit
The first
digit
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
D
E
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
Select any of
0 - 9
The second
digit
The first
digit
The second
digit
The first
digit
The machine does not start in
spite of pulling switch trigger,
but buzzers 2 sec. after pulling
switch trigger, depending on
the pre-selected figure of the
first digit.
For instance,
0 : one alarm of buzzer
1 : two alarms of buzzer
2 : three alarms of buzzer
9 : ten alarms of buzzer
Checking the functions
mentioned below.
For instance
* BPM. pre-select dial
* Stop of motor
* Buzzer
If the dial of second digit is set on "D", the machine does not
start in spite of pulling trigger switch.
The machine stops depending
on the pre-selected figure of
the first digit, after the the blow
is perceived.
For instance,
0 : stop with one blow
1 : stop with two blows
2 : stop with three blows
9 : stop with ten blows
Select any of
0 - 9

Features and benefits P 5 / 8
The relation between bpm. and fastening torque
Fastening standard bolt Fastening high tensile bolt
0 0
20
40
60
80
100
100
25 50 75
150
120
140
N.m
(Kgf.cm) N.m (Kgf.cm)
(204) 20 (204)
(408)
40 (408)
(612)
60 (612)
(816)
80 (816)
(1,020)
100 (1,020)
(1,224)
120 (1,224)
(1,428)
140 (1,428)
160 (1,632)
180 (1,836)
200 (2,040)
220 (2,244)
240 (2,448)
260 (2,652)
(bpm.)
(Dial pre-
selection) 25 50 75 98 99 99 (Dial pre-
selection)
50
1 2 3 1 2 3 4 5 6
(Time: sec.) (Time: sec.)
Standard fastening
torque for M 16
Standard fastening
torque for M 14
Standard fastening
torque for M 12
Standard fastening
torque for M 10
M12
M14
M16
100 150 196 250 300 (bpm.)
50
Standard fastening
torque for M 12
Standard fastening
torque for M 10
Standard fastening
torque for M 8
M10
M8
M12
Comparison of products
Specifications
Battery Voltage (V)
Current capacity (Ah)
Energy Capacity (Wh)
Cell
Type
Fastening torque:N.m (kgf.cm)
Net weight: kg (lbs) (including battery)
Model
BTW151
Makita
14.4
2.0 3.3
28.8 47.5
BH1420 BH1433
Ni-MH
0 - 2,300
0 - 3,000
150 (1,530)
1.9 (4.2) 2.2 (4.9)
No load speed (min-1=rpm)
Impacts per minute (min-1=ipm)
193 (7-5/8)
78 (3-1/16)
253 (10)
* 225(7-5/8)
* 60(3-1/16)
* 235(10)
225(8-3/16)
60(2-3/8)
235(9-1/4)
276 (10-7/8) 276 (10-7/8)
(including battery) (including battery)
BTW150 * 6931D
14.4 14.4
57.6
2.0 4.03.3
28.8 47.5
BH1420 * 1402BH1433
Ni-MH Ni-Cd
0 - 2,300
0 - 3,000
150 (1,530)
0 - 1,900
0 - 2,300
147 (1,500)
1.9 (4.2) 2.2 (4.9) 4.2 (9.3)
193 (7-5/8)
78 (3-1/16)
253 (10)
Dimensions
Length : mm ( " )
Height : mm ( " )
Width : mm ( " )
* 6931D : The power source is a shoulder slug type battery, to which Mod.6931D is connected with cable.

Repair P 6 / 8
< 1 > Disassembling housing R and L
Remove hammer case from housing R and L. So, housing R can be separated from housing L.
Anvil can be disassembled from hammer case.
< 2 > Disassembling hammer
(1) Press down hammer with 1R045: Large gear extractor
by turning the handle.
(2)Adjust the opening for steel ball inserting to the cam groove top of spindle.
(3)Take off 2 pcs. of steel balls 5.6 from spindle.
< Note > 25 steel balls 3.5 are installed in hammer.
Check the quantity when assembling.
< Note > When assembling anvil to hammer case, put 0.1g MAKITA grease N No.1 to the cylindric part of anvil.
Fig. 1
Spindle
Cam groove top
of spindle
Opening for steel
ball inserting
Steel ball 5.6 x 2
Steel ball 3.5 x 25
Hammer
1R045 Large gear extractor
(4) Apply grease to the position No. 1, 2, 3 and 4 as listed below, when assembling.
(1) to Spindle
(3) to Steel ball 5.6 x 2
(2) to Steel ball 3.5 x 25
Hammer
(4) to Spur gear 22
Fig. 3
MAKITA
grease N No.1
Molybdenum
di-sulphide lubricant
(1)
(2)
(3)
(4)
0.5g 0.2g
0.2g
0.5g
1.0g
0.6g
Ball bearing 6901LLB
< Note > Make sure that 25 pcs.of steel
balls 3.5 are assembled in hammer,
when assembling.

Repair P 7 / 8
< 4 > Removing ball bearing 6901LLB
Ball bearing 6901LLB is firmly assembled by pressing into internal gear case, and it is difficult to disassemble it
without any tool. For disassembling it, the following repairing tools are required.
(1) Bearing Puller
1R130~1R133 Initially, Slit is closed.
Hammer
Grip
Insert Bearing Puller (1)
into the inner wheel of Bearing (2).
Turn Shaft (3), it will go in,
then the Slit is opened,
and the Bearing Puller (1) catches Bearing (2).
(3) (2)
Hammer
Ball Bearing 6901LLB
Bearing Puller
Grip
Hit Grip strongly with Hammer,
the Bearing is pulled out by the shock.
Internal gear case
(3)
* Bearing pullers No. 1R130 - 133
* Bearing Extractor No.1R089
Bearing Extractor No.1R089
Circuit diagram
Color index of lead wires
Black
Red
Orange
Blue
Yellow
M1
M2
G
D
S
Lead wires of
end bell complete
M
Terminal
Switch
FET
White
Vinyl tube binding
5 yellow lead wires and
1 blue wire
Controller

Wiring diagram P 8 / 8
FET
Switch
Press FET lead wires and
the wires of end bell
complete into the bottom
of housing L.
Be careful, not to pinch
them with housing R.
Fix lead wires (red
and white) with lead
holder.
Controller
Place the tube protecting 6 lead wires
of controller, in the center of controller,
so that the tube and controller's lead
wires are not pinched by housing R.
Place the tube and controller's lead wires
on controller with bending them as illustrated below.
BPM. preselecting
dial plate
Tube and 6 lead wires
(6 yellow and 1 blue lead wires) bent
on controller
Controller
BPM. preselecting
dial plate
Pass lead wires connecting controller
and terminal, between the inner wall
of housing and boss for the controller
fastening screw.