Hitachi DH 50MR Manual

PRODUCT NAME
Hitachi Rotary Hammer
Model DH 50MRY, DH 50MR
The new Model DH 50MRY is capable of drilling maximum 50-mm diameter holes into concrete and compatible
with SDS max shank tools. Equipped with the low vibration mechanism, the performance, durability and operabilit
y
are greatly improved. The Model DH 50MRY is released with the low-vibration hammer drill Model
DH 40MRY as our low-vibration series.
The new Model DH 50MR is an upgraded version of the current Model DH 50MB. The performance, durability and
operability are also improved greatly even though it is not equipped with the low vibration mechanism.
LIST Nos.
DH 50MRY: E499
DH 50MR: E498
Sep. 2007
Drilling holes in concrete and drilling anchor holes.
Demolishing and chiseling of concrete. Edging, gravel road digging, compacting and tamping, grooving,
cutting, stripping and roughing, etc.
MARKETING OBJECTIVE
APPLICATIONS
SELLING POINTS
International Sales Division
D
<New features>
Equipped with a pendulum dynamic absorber as
the low vibration mechanism (Model DH 50MRY
only)
Fastest drilling speed and greatest chiseling
performance in the class
<Same features as the conventional models>
Vibration-absorbing handle
Constant speed with variable speed control
Easy-to-operate and double-molded switch handle
and side handle
Variable lock mechanism for easy working-angle
adjustment of chisels etc.
Needle-pin type slip clutch
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.

REMARK:
For more information about HANDLING INSTRUCTIONS, visit our website at:
http://www.hitachi-koki.com/manual_view_export/
Throughout this TECHNICAL DATA AND SERVICE MANUAL, a symbol(s) is(are) used in the place of
company name(s) and model name(s) of our competitor(s). The symbol(s) utilized here is(are) as follows:
Competitors
Symbols utilized Company name Model name
B BOSCH GBH-11DE
C MAKITA HR5211C

CONTENTS
Page
SELLING POINT DESCRIPTIONS ---------------------------------------------------------------------------------------- 1
SPECIFICATIONS ------------------------------------------------------------------------------------------------------------- 4
1. Specifications----------------------------------------------------------------------------------------------------- 4
2. Optional accessories ------------------------------------------------------------------------------------------- 5
COMPARISONS WITH SIMILAR PRODUCTS------------------------------------------------------------------------- 9
1. Specifications comparisons---------------------------------------------------------------------------------------------------------- 9
PRECAUTIONS IN SALES PROMOTION------------------------------------------------------------------------------10
1. Safety instructions ---------------------------------------------------------------------------------------------10
REFERENCE MATERIALS-------------------------------------------------------------------------------------------------11
REPAIR GUIDE----------------------------------------------------------------------------------------------------------------12
1. Precautions in disassembly and reassembly------------------------------------------------------------12
STANDARD REPAIR TIME (UNIT) SCHEDULES--------------------------------------------------------------------19
Assembly diagram for DH 50MRY
Assembly diagram for DH 50MR

-1-
Equipped with a pendulum dynamic absorber as the low vibration
mechanism (Model DH 50MRY only)
The Model DH 50MRY is equipped with the Hitachi's original pendulum dynamic absorber that absorbs
vibration from the main body by means of resonance of a leaf spring and a weight. As a result, the vibration
level of the Model DH 50MRY is remarkably lower than the current Model DH 50MB.
Fastest drilling speed and greatest chiseling performance in the class*
We conducted digital engineering to determine the optimal impact specifications. As a result, the Models
DH 50MRY and DH 50MR offer the fastest drilling speed and greatest chiseling performance in the class.
*Based on our own research
<Test conditions>
Direction : Downward drilling
Pushing force : 98 N (10 kgf)
Test material : Concrete panel with a compression strength of 2,352 N/cm2(240 kgf/cm2)
SELLING POINT DESCRIPTIONS
Weight
Leaf spring
0
100
200
300
400
22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54
Drill bit dia. (mm)
Drilling speed (mm/min)
DH50MB
C
B
DH 50MRY
DH 50MR
DH 50MB
Drilling speed comparison
C
B

-2-
Chiseling performance varies considerably depending on the work conditions. Use the factory
test results for comparison purposes only.
Refer to the Technical Data and Service Manual of the current Model DH 50MB for the following.
Vibration-absorbing handle
The two vibration-isolating rubbers provided between the
handle and the crank case, and also between the handle and
the housing efficiently absorb the vibration transmitted from the
tool main body to minimize transmission of vibration to the
operator’s arms.
Dial type, constant speed with variable speed control
The Model DH 50MRY/DH 50MR is equipped with a built-in
electronic control circuit that can adjust the number of hammering
steplessly between 1,050 and 2,150 min-1 with the dial. Even though
the load varies, the Model DH 50MRY/DH 50MR provides better
operability and stable and efficient drilling performance because the
constant speed control minimizes changes in number of rotation and
hammering.
130
160
115
160
0 50 100 150 200
Chiseling amount (kg/30 min)
DH 50MRY
DH 50MR
DH 50MB
C
B
Vibration-isolating rubber
Vibration-isolating rubber
Handle side
Dial
Chiseling performance comparison
DH 50MB / List No. E455

-3-
Easy-to-operate and double-molded switch handle and side handle
The base material of the switch handle and the side handle is plastic resin. The plastic resin base is
integrally molded with soft resin to realize a double layer structure. Thus the grip of the switch handle and
the side handle is soft for easier operation.
Change lever for switching between “Rotation + Hammering,”
“Neutral” and “Hammering only”
The Models DH 50MRY/DH 50MR provides three
functions, “rotation + hammering” function (for drilling),
“neutral” function (for positioning the tool tip) and
“hammering only” function (for chiseling and chipping).
These function modes can be easily switched by using the
change lever. The tool angle can be easily changed in 12
steps by turning the grip with the change lever positioned
at “Neutral.”
Needle-pin type slip clutch
The Model DH 50MRY/DH 50MR is equipped with a needle-pin type slip clutch for higher slip torque
accuracy and enhanced safety (same as the Model DH 50MB).

-4-
1. Specifications
Model - DH 50MRY DH 50MR
Drill bit (Max. dia.): 50 (2”)
Capacity mm Core bit (Max. dia.): 160 (6-1/4”)
Voltage V 110 120 220 230 240
Current A 14.0 12.8 7.0 6.7 6.4
Power input W 1,400
Enclosure -
Materials : Aluminum alloy die casting (Cylinder case)
Nylon resin (Handle (A). (B), tail cover, hood,
crankcover,backcover)
Polycarbonate resin (Housing)
Paint : Green, black, gun metallic silver, silver
Switch - Trigger switch
Type of handles - D-shaped handle and side handle
Full load rotation rate min-1 110 - 230
Full load impact rate min-1 1,050 - 2,150
Packaging - Corrugated cardboard box with plastic tool case
Product*10.5 (23.1) 10.0 (22.0)
Weight Packed kg (lbs.) 16.0 (35.2) 15.5 (34.1)
Standard accessories -
· Plastic case----------------------------------------------------- 1
· Side handle----------------------------------------------------- 1
· Stopper --------------------------------------------------------- 1
· Grease (A) ----------------------------------------------------- 1
*: Excluding cord and side handle
SPECIFICATIONS

-5-
2. Optional accessories
(1) Drilling work for through-hole drilling (Rotation + Impact)
D mm L mm Code No. D mm L mm Code No.
16 (5/8”) 340 (13-3/8”) 313448 16 (5/8”) 540 (21-1/4”) 313456
19 (3/4”) 340 (13-3/8”) 313449 19 (3/4”) 540 (21-1/4”) 313457
22 (7/8”) 320 (12-5/8”) 313450 22 (7/8”) 520 (20-15/32”) 313458
25 (1”) 320 (12-5/8”) 313451 25 (1”) 520 (20-15/32”) 313459
28 (1-1/8”) 370 (14-9/16”) 313452 28 (1-1/8”) 570 (22-7/16”) 313460
32 (1-1/4”) 370 (14-9/16”) 313453 32 (1-1/4”) 570 (22-7/16”) 313461
38 (1-1/2”) 370 (14-9/16”) 313454 38 (1-1/2”) 570 (22-7/16”) 313462
40 (1-9/16") 370 (14-9/16”) 313455 40 (1-9/16") 570 (22-7/16”) 313463
(2) Drilling work for anchor holes (Rotation + Hammering)
Drill bit (Taper shank)
(1) Drill bit (Taper shank) (2) Taper shank adapter (3) Cotter
D mm L mm Code No. Taper dimension Code No. Code No.
11.0 (7/16”) 100 (4”) 944460
12.3 (15/32”) 110 (4-5/16”) 944461
14.3 (9/16”) 110 (4-5/16”) 944462 Morse taper No.1 313464 944477
14.5 (9/16”) 110 (4-5/16”) 944500
17.5 (11/16”) 120 (4-3/4”) 944463
SDS-plus shank bit adapter
Code No.
313465
Drill bit (SDS max shank)
+
D
L
(1) Drill bit (Taper shank)
+
(2) Taper shank adapter
(SDSmaxshank)
(3) Cotter
D
L
+
Drill bit (SDS-plus shank) SDS-plus shank
bit adapter
(SDS max shank)

-6-
(3) Boring work for large-diameter holes (Rotation + Hammering)
(2) Core bit (1) Center pin (3) Core bit shank (SDS max)
D mm Guide plate l mm Code No. L mm Code No.
25 (1”)
29 (1-1/8”)
---
32 (1-1/4”)
35 (1-3/8”)
300 (11-13/16”) 313466
38 (1-1/2”)
147 (5-25/32”) 956009
45 (1-3/4”)
50 (2”)
54 (2-1/8”)
64 (2-1/2”)
65 (2-9/16”)
79 (3-1/8”)
80 (3-5/32”)
90 (3-17/32”)
94 (3-11/16”)
100 (3-15/16”)
105 (4-1/8”)
120 (4-3/4”)
125 (4-29/32”)
133 (5-1/4”) 955165 300 (11-13/16”) 313467
(4) Hole drilling
13 mm drill chuck (13VLD-D) with chuck wrench Chuck adapter
Code No. Code No.
321813 313468
(5) Chemical anchor holes drilling work (Rotation + Hammering)
Socket square size mm Code No.
12.7 (1/2”) 313469
19.0 (3/4”) 313470
lL
Chuck adapter
(SDS max shank)
Chuck wrench
13 mm drill chuck
(13VLD-D)
Chemical anchor adapter
(SDSmaxshank)
(Socket)
(1) Center pin (Guide plate) (2) Core bit (3) Core bit shank
(SDSmaxshank)

-7-
(6) Crushing work (Hammering mode)
Bull point (SDS max shank)
L mm Code No.
280 (11”) 313471
400 (15-3/4”) 313472
(7) Groove digging and edging (Hammering mode)
Cold chisel (SDS max shank)
L mm Code No.
280 (11”) 313473
400 (15-3/4”) 313474
(8) Cutting and stripping (Asphalt cutting etc.) (Hammering mode)
Cutter (SDS max shank)
L mm Width mm Code No.
400 (15-3/4”) 50 (2”) 313475
(9) Scooping work (Hammering mode)
Scoop (SDS max shank)
L mm Code No.
400 (15-3/4”) 313476
(10) Surface roughing work (Hammering)
Bushing tool Shank (SDS max shank)
Code No. L mm Code No.
313477 220 (8-21/32”) 313479
L
L
L
L
L