Drilling 16mm hole in concrete: pilot hole?

[brightspark]

dont bother with a pilot hole just go strait in . with a pilot it can snatch and chip the carbide cutting edge and also break your wrist or knock you of the steps unless drill has a clutch even then its dodgy

 

[tom2207]

What do you mean by 'concrete ceiling'? Is it proper reinforced concrete or beam and block? if proper concrete then as others have said, straight in with 16mm. If its other types of crumbly concrete, I would probably use a pilot.

different story if its bison slab though.

 

[brightspark]

different story if its bison slab though.

soon get through them with a big hilti sds max and a quality bit. i grind proper cutting edges on some of my masonary drills rather than just impact. they cut concrete wood and steel

 

[tom2207]

soon get through them with a big hilti sds max and a quality bit. i grind proper cutting edges on some of my masonary drills rather than just impact. they cut concrete wood and steel

yep , but what do you do with the hole and a concrete fitting , to hang a hammock off .

 

[JMS1972]

soon get through them with a big hilti sds max and a quality bit. i grind proper cutting edges on some of my masonary drills rather than just impact. they cut concrete wood and steel

Really good for phosphor bronze too, sharpen the sides as well as the tip and it never binds up.

 

[Kayos]

I usually pilot 10mm, more to check it exits where I expect it to

Then 20 ish, then 30 to finish.

Id probably drill 16mm without a pilot, depending on location

 

[Rkweld]

I would say it depends if your positioning of the hole is critical, the 16mm may wander, if you think thats likely a small pilot will help.

 

[brightspark]

I would say it depends if your positioning of the hole is critical, the 16mm may wander, if you think thats likely a small pilot will help.

a 6.0mm will do nicely. it will find if theres any rebar in the way as well as drill through a lot quicker

 

[Kram]

My experience concrete can be brittle and be weakened by normal drilling, often knocking chunks out the back, or cracking a fence post as an example.

Diamond segment drills are cheap particually the small ones, and they can be driven by a light weight cordless, so much better for overhead working. No need for pilot.

 

[Pete.]

Fence posts are very brittle, not easy to drill without losing chunks off them.

16mm in concrete is straight in even with a battery SDS. If you're really short on power you can pilot it with a drill not more than 50% the next size up.

At work we drill anything up to 30mm straight in (with a proper SDS MAX drill like a TE80) but for 32mm holes we pilot with a 16mm drill because 1. it's faster 2. It's easier on the hands and 3. It saves wear on the spiral of the expensive 32mm bit.