Drilling into granite 1

[csd72]

Anyone out there have experience drilling into granite.

I need to drill some 1"diam anchors 12" into 18" thick granite masonry with Hilti epoxy.

I am trying to get in touch with Hilti, but it would be good to hear some other opinions.


csd

 

[civilperson]

Why so deep? Why so large a diameter? Try 3/4" diameter HIT-TZ rods with 5 1/4" embedment. Holes made greater than half the thickness is how the quarries split out the granite from the face. See allowable and ultimate Steel strengths in HILTI 2006 Technical Guide. Use as many as needed for the total loading, (minimum spacing of 10").

 

[SlideRuleEra]

As a bridge contractor we sometimes had to drill sizable, deep holes into granite (for explosive charges). Suggest forgetting about electric tools for what you are describing and go with a rotary-impact pneumatic drill (jackhammer) driven by a suitably sized air compressor.

Note: The impact-only tool that "the public" often refers to as a jackhammer, and is used for tearing up streets, etc., is actually a "pavement breaker" (in the US, anyway).

http://www.SlideRuleEra.net