Are cheap diamond core drills on eBay any good?

[braychurchmouse]

I need to drill a hole through brick to take a fan duct - external diameter 110mm. I've spotted several diamond core drills (SDS) 117mm diameter including arbor and pilot drill on eBAY for around £25 plus £7 postage (do ebay search for "diamond core drill 117mm").

I have an SDS drill already so thats sorted. Basically its just for the one job, then I'll probably sell it back on ebay as "used once" !!!

The sort the pros use I know cost around £70..... so whats the catch?

Also I understand you use these dry...is there any advantage to running water over them while drilling (gets the wife involved .?

And i guess you use it with hammer action "off".???

Thanks in anticipation of the usual assistance from this excellent forum.

 

[^woody^]

Unless you plan on core drilling the whole street, then a cheap one will do fine.

Generally they have fewer/lower quality diamond grit so don't last as long as more expensive ones, but are still good for a few holes

But more expensive ones, may well be the same bit but with a different colour paint and name on it!

Dry bits are uses dry and not dampend, and yes, hammer off

 

[2face]

i have a set .. yes as good as any other ... also hammer on .. !!!!! seriously hammer on .. )) we aint got all day .

 

[Softus]

I have an SDS drill already so thats sorted.

Er, no it isn't. There are special drills for this kind of work - they have a clutch so that a snatching core bit won't end up breaking your wrist or your jaw.

 

[kevplumb]

i have a set .. yes as good as any other ... also hammer on .. !!!!! seriously hammer on .. )) we aint got all day .

and if you use them with hammer you are a fool sir

Er, no it isn't. There are special drills for this kind of work - they have a clutch so that a snatching core bit won't end up breaking your wrist or your jaw.

howay soft most sds have a clutch me owld dewalt has

 

[Softus]

howay soft most sds have a clutch me owld dewalt has

Yes, sorry, my post wasn't very clear. I merely meant that the clutch on an ordinary SDS+ drill isn't adequate.

 

[chr15]

You get what you pay for with diamond core drills but in general if you're drilling brickwork/blockwork then a cheapie will usually do,just make sure you keep clearing the dust as you drill else you'll get a jam up. And your sds clutch will do fine but you might end up burning your motor out cos a drill designed for diamond coring will have a bigger motor more suited to the job.

 

[braychurchmouse]

Thanks folks, for all the replies. I really appreciate it. I'll let you know how I get on.