Advice on core drills

[tonyb61]

I need to cut a couple of 40mm and a 32mm hole in a 9" solid brick wall over the next few weeks, and am weighing up buying tct or diamond core drill bits to drill these rather than renting from HSS or Jewsons's. I have an SDS+ drill with clutch already so the difference in cost is small, and I have the core drill bits to use when I need them, which is usually at the weekend. TCT bits are much cheaper, and seem fine as the bricks are standard soft house bricks, and I only want to cut a small number. Is it worth using diamond cores ?

Thanks

 

[lame plumber]

just hire a core drill n core, or buy a tct core for your sds which is too slow for diamond coring

 

[Millsy 82]

Tct won't be as neat as diamond.

Unless your doing a lot or drilling hard walls just buy a cheaper set and use your sds. I used mine for years with diamond upto 5", yes it took a little bit longer and it will wear the drill out a little bit quicker but it will do the job.

If you are drilling a lot buy a core drill and decent bits. If you only need to drill a few through hard walls hire one.

 

[lame plumber]

re wearing out sds drills, it took screw fix 6 replacements to cotton on and me one stiched up face to realize sds and diamond arent very clever.

 

[Radioman]

Cheap way out is sds and tct. Diamond with sds will work until you come across really damp bricks, or a course of engineering bricks

 

[joni os]

52mm diamond core bit will do for both size pipes and allow movement and tolerance. If drilling damp bricks diamond matrix can become clogged, but easily cleaned by using core on dense concrete block or similar to expose diamonds. Do not use hammer action.

 

[tonyb61]

From what some posters say, using sds+ drills is risky with diamond core bits ? Is that because the bits or drills break ?

 

[SimonG]

For two holes just machine gun it. Mark your circles and drill series of holes, 7mm, around it and then use chisel on sds drill to knock out centres.

 

[gmartine]

From what some posters say, using sds+ drills is risky with diamond core bits ? Is that because the bits or drills break ?

The sds mechanism can be too aggressive so the segments of the core bit can snatch in the material, and if your clutch is a bit firm it could send you spinning or worse break something especially on the larger diameter cores.The "teeth" of diamond core bits are really no such thing, they are not designed to cut and quickly remove material just abrade.

Either type of bit will be fine as the diameters are small, if you're not going to use them again go for the cheapest option.

 

[tonyb61]

Just to finish off this post, I bought a cheap set of diamond cores, and they worked fine, nice clean holes, and in fact I also cut an extractor fan outlet with the same set. The clutch worked fine on the drill too when the bigger core got stuck.