Concrete Screws, thoughts?

[Martin Cole]

also know as thunderbolts, which are perfect for projecting signs.

There was a thread on these not long ago. An easy fit just drill into wall and screw in, no plugs required.

I use a socket wrench which makes it easier. Incredibly strong fix once fitted

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[Jeff]

you will get a very strong fixing with these. take your time drilling the hole to ensure a snug fit.
makes you wonder how the hell a plastic rawl plug was ever used successfully?

[Gavin Dooley]

Use with an impact driver & you’ll be sorted.

[RobertLambie]

Concrete screws are excellent. but slightly differ in the way you drill the hole. by that I mean, sandstone or red brick etc.

Sometimes I drill the hole, crank in the bolt with a socket rachet to make sure its tight and cut its thread and isn’t clogged by the stone dust etc. take it back out and then offer up the sign, align the holes and then screw the bolt back into the prepared hole.

A tip, if possible. is to try drilling a test hole somewhere out the road but on the same building and brick.
this is because some masonry is softer than others and when you drill the hole it can crumble. this means the hole is slightly looser than required and the threads do not catch and hold as secure. If this happens, try using a slightly narrower drill bit than the one recommended to use with the thunderbolt.
Trust me when I say, there is nothing worse than drilling a series of perfectly aligned and drilled holes, only to find the masonry is soft and crumbles and you need to start again, or purchase a liquid fixing and inject the holes.

Thunderbolts and screws come in various styles, lengths and sizes. the ones Martin has shown are the ones I prefer to use. I just find the threads and hex-head work best for the purpose.

[Adam McMonagle]

Well I have learned something from this, I was unaware of Thunderbolt screws, I always use Anchor bolts, this requires precision drilling and you cant remove them once in, well not easily.

[John Hughes]

DON’T use an impact driver! The bolts are meant to be used with a socket or spanner and screwed in. Even using a drill is not the best … you can too easily over tighten.