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| The size is o1/2" (12.5mm), but that of only the IT carbide drill is o1/4" (6.5mm). |
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| Electric drill |
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| ・Percussion drill |
: Hitachi DV-20VB |
| ・SDS-plus bit |
: Bosch GBH2-24DSE |
| ・Hex shank bit |
: Hitachi PR-38E |
| ・IT carbide drill |
: DV-20VB (1,100rpm) |
・IT diamond drill
straight body |
: DV-20VB (2,900rpm) |
| ・IT Drill |
: DV-20VB (2,900rpm) |
| ・Mistdia Drill Bit |
: Hitachi DW12SA |
| ■Note: |
The reason why the noise level of the Mistdia Drill Bit is a little higher than those of the IT Drill, IT carbide drill, and IT diamond drill straight body is that the rotation speed of the used electric drill DW12SA is as high as 10,000 rpm. |
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○ These tests were performed on the third floor of a three-story reinforced concrete building.
○ Because the workshop was under reform, its interior decorations were removed. |
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