Core bit drilling, hammer on or off?

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Forum topic by 404 - Not Found posted 09-24-2013 10:11 PM 2379 views 0 times favorited 4 replies Add to Favorites Watch
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404 - Not Found

2544 posts in 2969 days

09-24-2013 10:11 PM

I have looked for answers to this question on t’internet, but there are a lot of conflicting opinions ranging from ‘use hammer action’ to ‘using hammer action will destroy the bit’.
Does anyone know how to correctly use a tct core bit in a concrete block wall?

I know it’s not wood related and I should probably post it on HomeRefurberJocks, but if I do I won’t hear anything back for a week and I’ve got to move these pipes tomorrow.

Thanks in advance

4 replies so far

View Hammerthumb's profile


2844 posts in 1975 days

#1 posted 09-24-2013 10:17 PM

Don’t know about concrete blocks, but when we use them on stone countertops we have the hammer action off. I don’t think it would destroy the bit, but it is easier to drill with it off. And with stone, hammering action might create fractures in the material being drilled.

-- Paul, Las Vegas

View JayT's profile


5632 posts in 2211 days

#2 posted 09-24-2013 10:28 PM

Hammer off, just rotation.

Hammer drill with a percussion bit is designed to break up the masonry at the bottom of the hole through the hammer impact, then the twist removes the waste and turns the bit to a new spot to break up more concrete.

A core drill grinds/cuts through the masonry with diamond teeth. All hammer action is going to do is shorten the life of the core bit because it will cause the diamond particles to fracture and thus lose their cutting edges more quickly.

I would bet that many of the people saying to use the hammer action are trying to use a core bit that is worn out and won’t cut anymore, so instead of replacing it, they turn on the hammer and have an oversized, expensive percussion bit.

-- In matters of style, swim with the current; in matters of principle, stand like a rock. Thomas Jefferson

View bigblockyeti's profile


5121 posts in 1720 days

#3 posted 09-24-2013 10:32 PM

Hammer off for diamond core bits, hammer on for carbide boring bits. Some bits require water, some not.

View Nicky's profile


695 posts in 4092 days

#4 posted 09-24-2013 10:33 PM

+1 JayT

Reasonable explanation

look at

-- Nicky

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