Silverline 406549 Diamond Core Drill Bit 152 x 150 mm

 

Its a core bit, if you need one this is cheaper than most. Only needed for one hole, but my other silverline core drills are happy with 15+ cores. 152 is as large as you can go with a ‘normal’ SDS drill, after that you need to hire one.

 

Hubby used this to drill a hole through a cavity wall. The inner skin was lightweight block, the outer a dense concrete block. It took about 2 minutes to go through the inner skin, and 5 or 6 to go through the denser block. He used a 1500W SDS drill with a safety clutch (to avoid breaking arms/wrists – this is a genuine risk, be careful). No hammer action was used. It created a huge amount of dust but provided a nice clean hole. He was able to drill all the way through from inside and used an internal fit wall kit to avoid having to have any scaffolding outside. I’m not sure there is much diamond on the cutting tips compared to more premium brands, but it’s good value for money and seems perfectly adequate for occasional use or one-off jobs, providing your drill is up to the task.

 

Perfect. Did the job of making a hole through a cavity brick wall. Did a nice tidy job, took an hour or 2 to get through but used it quite slowly to create less dust. Looks like it’s got plenty of wear in it still, should be good for a few jobs. But I’m glad to say I am never going to do something like this again as holding an SDS drill for this amount of time is a killer boring job

 

I used this to drill through 58 cmm of poured concrete wall. It was very slow progress but the concrete was very tough even with hammer and chissel. It was cheap, and did the job. Probably would have worked far better on a softer material such as brick or breeze block.

 

Had to put in some 100mm extractor fans, which needed holes cut through 12 inch thick brick and cinder block cavity walls. Got this 107 mm diameter by 150mm long core drill, as it was cheaper that getting someone in to do the job.

I was lent a 110mm TCT Core Drill Bit, but that was too shallow to get through a course of brick in one go, so it needed a lot of extra chiselling.

With this I was able to cut straight through the wall from one side in one go, occasionally stopping to remove debris, from inside the warm house, on a cold day.

My SDS drill is not the best quality and struggled a bit with such a large cutter, sometimes causing the safety clutch to slip, but with care it worked ok.

I bought this together with the “Silverline 124518 SDS Plus Core Drill Arbour 200mm” and “Silverline 769992 Morse Tapered Guide Drill Bit 8mm x 200mm”.

The instructions were in the tiniest writing I have ever seen, or could hardly see, part of which read as follows;

Important notes
* NEVER use hammer or impact action with diamond core drill bits;
* this will damage the cutting edges, increase the risk of jamming and possibly bend longer arbours and arbour extensions
* Core drill bits should only be used with drills with safety clutches, with the possible exception of small core drills
* Core drills, arbours and extensions are heavy, and core drilling creates a large load for the motor of the power tool, even at low rpm. It is important to consider this when selecting a suitable power drill for the diameter and depth of the hole you wish to drill. It may be necessary to use the `stitch’ drilling technique first and then finish with the core drill to make the final cut for the hole

So it was not until I finished and then scanned, enlarged and transcribed the instructions I able to read them and then realised I should not have used any hammer action with the SDS drill. However the cutter still seems in pretty good condition.

The guide drill was a bit prone to falling out, particularly with the hammer action, so was firmly tapped into place and stayed in long enough for the core drill to get deep enough to guide itself. Otherwise it all worked ok for me and achieved what was needed at an acceptable cost.

 

I bought this with the Faithfull DCSDSBSP Adaptor SDS x 1/2-inch BSP and the Faithfull Drycore Taper Wedge Mas Drill 200MM. The DCD fitted well into the arbour – very solid and true, so no problems there. The tapered drill bit was another matter – all over the place. However, I can confirm that the DCD and Faithfull arbour combination works very well. Once it’s cut in, no problems and nice clean hole – through block and then brick. The only potential issue was that the DCD was about 1cm too short for my wall, so be careful of your measurements…

 

As an electrician, this is a very common size I use. In the past I have always bought the expensive core bits, but this time as money was tight I thought I would try the budget range. To be honest, I was thinking I would use this core for the job we are on the either have it re tipped or bin it, as every other bit of Silverline kit has lasted 5 minutes if I was lucky.

Any way, we cored 2 holes through breeze block and common building brick, 2 holes through concrete block and sandstone and 1 hole through a single leaf sandstone wall. Amazingly, this core bit still has 5 mm of the tips left and will do at least another 6 or so holes in similar materials.

As for the cutting performance, I couldn’t honestly tell any difference between this bit and my previous more expensive Faithful Tools bit. It probably helps with the fact that we use a proper core drill Dewalt D21580K 1705W 1/2-inch Male BSP 2-Speed Dry Diamond Drill 240V and not the useless SDS arbors they sell for use with these cores.

One last thing, as the manufacturer or Amazon don’t bother listing it, the thread size on the core bit is 1/2 inch BSP, so will fit the same arbors as other more respected makes of core bit.