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7-5. Number of Screws or Bolts Driven
7-5-1. Per-charge working capacity comparisons
Test data on the number of screws or bolts which can be driven per battery charge by the new models vs. the
previous models are shown in the tables below. Please note that the data below are intended for general
reference only as the number of screws which can be tightened per charge will vary slightly depending on screw
tightening conditions, screw sizes, ambient temperatures and the charging capacity of the battery.
(1) Number of screws or bolts driven (Cordless impact driver)
Battery
Tightening condition
Model
HITACHI
WH 12DM
HITACHI
WH 12DH
C
EB 1220BL
EB 12B
1222
(Corresponding EB 1220BL)
Wood screw 4.0 mm dia. x 50 mm
(soft wood)
575
545
635
Wood screw 4.2 mm dia. x 90 mm
(hard wood)
115
110
105
Wood screw 5.3 mm dia. x 120 mm
(hard wood)
45
40
40
Machine screw
(M8 x 16 mm)
1,280
1,215
1,475
Note 1) The Model WH 12DM is equipped with the larger hammer and the higher power motor for the higher
tightening speed. Although the higher tightening speed is realized, the Model WH 12DM has the
following disadvantage.
High startup current
The Model WH 12DM consumes higher power than C for driving a short or machine screw because it
requires high startup current. Thus the number of machine screws driven per charge is different as
shown above.
Battery
Tightening condition
Model
HITACHI
WR 12DM
HITACHI
WR 12DH
EB 1220BL
M10 (3/8")
ordinary bolt
755
0.4
Number of bolts
Time (sec.)
M12 (15/32")
ordinary bolt
475
0.6
Number of bolts
Time (sec.)
M14 (9/16")
ordinary bolt
335
0.9
Number of bolts
Time (sec.)
EB 12B
755
0.5
475
0.8
335
1.2
(2) Ordinary bolt (Cordless impact wrench)