How to judge quality of SDS drill bits?

[ukworkshipper]

Hello All,
I have bought my first set of SDS drill bits from ebay, it is a no-name set that came to roughly 1 euro a piece. I have been using them for about a year on concrete blocks and a few ceramic tiles with my Bosch hammer drill (2-28F), I haven't had any problem aside from the fact that when the hammer drill spins freely I see some radial axis play on the bits, but according to the Bosch manual this play is normal and is minimal when the drill touches a surface. I recognize that some drilling turned out to be less precise than I wanted.

In any case, to get more precise holes I am wondering about the quality of these bits. Aside from being straight, what other characteristics should I look at to tell if they are of poor quality or decent enough quality? I have read some discussions in forums that unbranded drill bits from ali/ebay can be just as good as some more famous brands. But I am not sure how to judge quality. Any feedback is appreciated!

 

[Homeless Squirrel]

SDS drilling isn't about "Precision" for one the bit isn't fixed into the chuck just a push in/click held bits.
If you want precision your better off starting with Multi construction drill bits to start hole then SDS the rest.
You rarely wear SDS bits out unless using all day long into dense concrete and forceful
Ive still got the stash of bits i got when i bought my Makita SDS probably 15 years odd ago!

 

[ChaiLatte]

If you want precision...
You rarely wear SDS bits out...

If the positon of a hole is critical, set the SDS machine to hammer-only and use it initially as a centre punch, to slightly indent where the hole needs to be. It is the combination of going round and round and bouncing up and down where the point touches the surface that causes holes to wander not any minor lack of concentricity in the system.

SDS bits are available in 'two flute' and 'four flute' (see an example of 'four flute': https://therailwayshop.co.uk/products/hilti-te-cx-50mm-drill-bit). For me, the four flute ones are preferable, but not something I would go out of my way to buy at extra cost.

The only thing to watch out for with well-used SDS bits is the fluted shank, which is made of softer material than the carbide tip, can wear due to abrasion. That makes it smaller diameter than the tip and reduces the ability of the flutes to clear the dust, meaning it can get harder and harder to withdraw the bit from the hole.

 

[ukworkshipper]

Thanks for the great feedback! I have seen the trick of punching a small dent on the point of drilling with a nail or an awl, or as you described, or also use painter tape to avoid the wandering of the bit.

But from what I understand hammer drills even with the hammering action turned off are always slight out of concentricity compared to a regular drill.

I need to make precise holes in ceramic tiles and am debating if it's worth it to buy one of those expensive diamond bits just for making a few holes.

 

[ukworkshipper]

SDS drilling isn't about "Precision" for one the bit isn't fixed into the chuck just a push in/click held bits.
If you want precision your better off starting with Multi construction drill bits to start hole then SDS the rest.

Thanks for the tip, could you please elaborate what's so particular about multi construction bits, why are they more prices? Is it because they are not SDS?

Any specific brand you recommend? I see that term used in those blue Bosch bits, I think other brands call them multi-material?
I have found these two sets which are the best rated with a reasonable price, but I don't know the Saxton brand.

Bosch

Saxton

 

[Distinterior]

I need to make precise holes in ceramic tiles........

Ceramic tiles vary in their hardness from really quite easy to drill, to a porcelain type tile, which can be a real b u g g e r to drill without a specialist type drill bit.

Also, the choice of drill bit to use can be affected by the make up of the wall the tiles are mounted on......You certainly dont want to be using an SDS type drill on tiles fixed to a plasterboard wall.

Personally, I would try a Multi Construction/ Material drill bit first in a battery drill, no hammer action!.....and see how easy/ difficult the tiles are to actually drill.
They will give you the cleanest, most accurate hole without undue stress on the tile.

 

[Spectric]

In any case, to get more precise holes I am wondering about the quality of these bits.

Depends what you mean by precise, holes in concrete etc only need to be in the right place rather than precise. Do you mean perpendicular or location ?

If you buy SDS bits from the likes of Bosch or Dewalt then you have good bits, also look at

https://www.ukdrills.com/drill-bits/sds-drillshttps://www.ukdrills.com/drill-bits/sds-drills

It would help if we knew what you are doing and the hole sizes / fixings being used because you have chemi fixings, frame fixings and plugs that are in common use.

 

[Sideways]

For an "ordinary" indoor tile, those drills that have a single flat piece of tungsten carbide shaped like a spear point actually make a nice clean hole. They tend to be cheap and I can't comment to their durability, but for a few holes might be worth trying.

 

[Phil Pascoe]

The chuck can make a difference. I have a 230v DeWalt SDS and I recently bought a 110v DeWalt SDS (£20, virtually unused). The chucks are of a slightly different design and the 110v drill is noticably more accurate (using the same bits). The 230v hasn't had a huge amount of work so I doubt the chuck's badly worn. Our blocks have chips of elvan in them which is hard enough to take a drill bit off course, but recently I drilled 36 holes for shelf brackets that needed to alingn and not one hole was out. (Hilti bits.)

 

[Distinterior]

I have a few Multi Material drill bits and the majority of them are the " Alpen" brand......Made in Austria and good quality! They will drill through the majority of ceramics, except the real hard porcelain.

Back in the day when I used to fit a lot of bathrooms, I invested in a diamond drilling system that comprised of a specialist arbour and different dia diamond bits to fit on the business end......It incorporated a pressurized water feed that kept the actual drill bits cool......It works an absolute treat but cost me a fortune at the time......Japanese if I remember correctly....?

 

[Phil Pascoe]

Didn't you mean it cost your customers a fortune?

 

[Distinterior]

Didn't you mean it cost your customers a fortune?

Oh, I wish!!
The customer supplied all the wall & floor tiles on that job at the time(25 years ago.....) and I didnt know what they would end up buying until I started actually fitting the bathroom.
It turned out, they had purchased the hardest tiles I had ever come across to date.
I had a lot of accurate, clean holes to drill in the wall tiles ( shower cubicle, wall mounted basin & pedestal, wall hung w/c, + all the chrome wall mounted accessories. )

Had I known beforehand, I would have built the cost of this specialist drill & drill bits into the price for the job.

These type of tiles are now readily available, so I have used it a fair few times since then, but it was a bit eyewatering at the time.....

 

[ukworkshipper]

The chuck can make a difference. I have a 230v DeWalt SDS and I recently bought a 110v DeWalt SDS (£20, virtually unused). The chucks are of a slightly different design and the 110v drill is noticably more accurate (using the same bits). The 230v hasn't had a huge amount of work so I doubt the chuck's badly worn. Our blocks have chips of elvan in them which is hard enough to take a drill bit off course, but recently I drilled 36 holes for shelf brackets that needed to alingn and not one hole was out. (Hilti bits.)

I wonder if my chuck is a bit out of axis.

Depends what you mean by precise, holes in concrete etc only need to be in the right place rather than precise. Do you mean perpendicular or location ?

If you buy SDS bits from the likes of Bosch or Dewalt then you have good bits, also look at

https://www.ukdrills.com/drill-bits/sds-drillshttps://www.ukdrills.com/drill-bits/sds-drills

It would help if we knew what you are doing and the hole sizes / fixings being used because you have chemi fixings, frame fixings and plugs that are in common use.

Precision as in location and size of the hole, I also don't want to crack the tile, which are glued to hollow cement bricks.

 

[Spectric]

I also don't want to crack the tile

Ok so your hole goes through a tile, initially avoid SDS and definately no hammer action. Use masking tape and put the mark onto this, then drill the tile using a drill with a tile drill to get through the glaze and tile, there is a big difference in drilling through ceramic tiles and porcellan tiles.

These are ok for ceramic tiles

https://www.ukdrills.com/glass-and-tile-drill

for porcellan then you need diamond

https://www.ctdtrade.co.uk/cutting-...-drill-bit-dry-gres-for-drills-dry-cut-6mm#ns

Once through the tile then the SDS massonary bit can be used, with hollow blocks try without hammer action initially and use something fast and light rather than something like a hilti that is slow but gives a heaver impact per stroke. Once the hole is done then for fixing to hollow blocks then these Fischer plugs are good assuming you are not fixing something really heavy to the wall.

https://www.fischer.co.uk/en-gb/products/standard-fixings/plastic-fixings/duopower

and I believe you can get them in srewfix / toolstation.

 

[Stevekane]

Ive not used them on tiles but Bosch Blue masonary drils are way better than any of my other drills, even a set of brand new Makita SDS drills struggled on some very hard brick but the Bosch drills were are delight to use. When you look at them they are the 4 point design and look more like a properly ground and sharpened drill.
Not too expensive in screwfix and the set has a pair of the most popular size.
Steve

 

[Phil Pascoe]

They are good .......... nearly as good as Hilti.

 

[ukworkshipper]

Ok so your hole goes through a tile, initially avoid SDS and definately no hammer action. Use masking tape and put the mark onto this, then drill the tile using a drill with a tile drill to get through the glaze and tile, there is a big difference in drilling through ceramic tiles and porcellan tiles.

These are ok for ceramic tiles

https://www.ukdrills.com/glass-and-tile-drill

for porcellan then you need diamond

https://www.ctdtrade.co.uk/cutting-...-drill-bit-dry-gres-for-drills-dry-cut-6mm#ns

Once through the tile then the SDS massonary bit can be used, with hollow blocks try without hammer action initially and use something fast and light rather than something like a hilti that is slow but gives a heaver impact per stroke. Once the hole is done then for fixing to hollow blocks then these Fischer plugs are good assuming you are not fixing something really heavy to the wall.

https://www.fischer.co.uk/en-gb/products/standard-fixings/plastic-fixings/duopower

and I believe you can get them in srewfix / toolstation.

Thank you for the excellent advice. I have a set of Fischer SX, I believe the duopower are better but from the load table don't seem that much better. Would a 10mm fischer SX every 25cm be good enough for kitchen cabinets?

 

[imaginarynumber]

After snapping the head on a SDS drill bit whilst drilling in to a concrete lintel and hitting a reinforcing bar, I went out and purchased a set of Makita Nemesis 4 flute drill bits. They went through the reinforcing bar with ease. Unlike regular SDS drill bits, the head is not offset and has a defined point



Never tried them on tiles though.

 

[Daniel2]

I have a few Multi Material drill bits and the majority of them are the " Alpen" brand......Made in Austria and good quality! They will drill through the majority of ceramics, except the real hard porcelain.

Back in the day when I used to fit a lot of bathrooms, I invested in a diamond drilling system that comprised of a specialist arbour and different dia diamond bits to fit on the business end......It incorporated a pressurized water feed that kept the actual drill bits cool......It works an absolute treat but cost me a fortune at the time......Japanese if I remember correctly....?

I had the Hilti version of that of which you speak.
Excellent piece of kit - gamechanger
In fact, I still have it, but I retired, so it doesn't get used much these days.

 

[martin45]

You probably are aware of this but I found out the hard way many years ago. I was using red rawlplugs. Drilled a lovely hole in the tile and wall using masking tape to mark etc. Inserted the rawlplug flush with the tile edge and promptly split the tile when I inserted the screw. From then on I trim the front edge off the rawlplug with a stanley knife and push it in until its behind the tile.