SDS drills: 2kg or 6kg?

[Stephen]

Hi,

I was looking at SDS drills. I see that there are 6kg drills and 2kg drills. At first, I thought that the 6kg drill was heavier because it has a bigger motor and that a bigger motor would be more powerful. However, looking at some of the specs. in the Screwfix catalogue, there doesn't seem to be much difference in how big a hole they can drill through various materials.

I notice the 6kg drills seem to be unknown/budget names whereas the

2kg drills are Bosch and the likes. Is it that these known manufacturers use better motors that can deliver more power per unit weight?

I imagine it's much more comfortable to hold a 2kg drill for periods than a 6kg one?

Are there any differences good/bad between them?

Thanks, Stephen.

[www.GymRatZ.co.uk]

Having started the sds route with a budget brand 6Kg drill + bits for ... about £20 or some such daft amount, as I didn't (don't) do a lot of drilling hard walls, it served(s) we admiribly.

Used more for light demolition work and chiseling out walls. Brilliant! My cordless combination did the other jobs.

However.... After we purchased an old cottage that needed a lot of battons fixing to a very hard stone wall the thought of weilding the mighty beast was to much so I bought a screwfix special on a "blue" bosch 2Kg for less than a £100

Made light work of the walls without killing me.

Still use the big bad budget boy for serious destructive abuse and keep the good one for the finer things in life.

Glad I have both, however budget biggie does consume and spit out a fair bit of grease these days. I think I have nearly killed it. :¬)

Pete

[Doctor Drivel]

Which is more powerful?

[www.GymRatZ.co.uk]

don't know to be honest. I think the budgest beastie has a larger wattage but that doesn't really mean much as it can get very hot which the 2Kg bosch has never had problem with.

More power on the label but more power dissapated is non practial energy.

I think... the budget drill is much lower geared too. I have drilled a couple of 5" cores with it but when it jammed...... definately NOT one to be hanging off a ladder using. :¬)

[The Medway Handyman]

By and large a 2kg SDS is a drill that can chisel and a 6kg is a breaker that can drill.

To an extent yes, but a cheap 6kg used as a breaker will do the job better than a 2kg drill.

Exactly.

You have to decide what your primary use is. If its 80% drilling 20% breaking then a 2kg is better. The other way around would indicate a 6kg.

I carry a couple of 2kg SDS machines in the van. One is a heavvy duty Wickes/Kress which is used for drilling/light breaking & does all the heavy/dirty work. The other is a cheap Ryobi which has no chisel function (no rotation stop) which I keep pristine for use indoors - drilling holes for curtain poles etc.

On a shelf just inside the workshop door is a cheap 6kg machine only ever used for breaking. Don't think its ever actually drilled a hole.

I reckon most DIY users start with a 6kg SDS because they can be bought cheaply (I did). Once they realise the benefits of SDS they then buy a brand name 2kg.

If you only want to drill, Screwfix have the Ryobi SDS for £40 at the moment. Very nice machine indeed, well happy with mine, but no chisel function.

Better to go for a 3 function machine. The Scrwfix 'Site' brand (made by Makita) 3 function SDS is around £115 & they have the Bluse Bosch at £110.

[John Rumm]

No they are usually heavier just because they lack any engineering finesse!

Partly that, also better gearboxes, ball raced mountings on the armature etc.

Indeed.

Yes - quite a number:

Some of the big lumps lack a safety clutch - important if turning big bits / cores.

Some have no speed control - or a poor crude one that does not deliver any torque at low revs. No speed control also means that the chisel mode is "all or nothing" which is ok if your intention is destruction, but not much cop for accurate chasing / cutting.

Many have no locking mechanism for the chisel when in roto stop mode. This means the chisel is free to rotate in use which makes them a right PITA for doing nice neat chases in walls for cable runs / socket cutouts etc. Better ones have a lock, the best have a multi position lock to let you lock off the bit at an angle of your choice.

Some big ones will spatter grease out the front (and need frequent relubrication)

Many of the more refined machines come with an alternate three jaw chuck these days that replaces the SDS one when using convention bits. Often the cheapies can only use a plug in SDS to three jaw conversion chuck which makes the drill longer and more wobbly.

[Doctor Drivel]

Are these cheap 4 to 6 kW machines good at core drilling? A TCT core bit with an SDS shaft can be used with hammer action, so I am led to believe, but as yet have never read that on any makers drill box or bumph. Diamond Core bits do NOT have hammer action.

If these cheapo 4 to 6 kg SDS machines are good at core drilling, then it may be best to use them only for that function and chiselling - B&Q sell one right now for £25. Then keep the quality machine for drilling holes.

Core drilling needs watts, usually 1,000 and above.

[dennis]

I put a 110 mm core drill through a concrete wall 9" thick using a Ryobi battery drill three weeks ago. Flattened three batteries but it did the job using hammer and light pressure. It took a while, mostly to let it rest between batteries, about 15 minutes of drilling at a guess.

I did have an SDS I could have used but I don't know if it has a chuck and I didn't intend to find out.

[Andrew Gabriel]

I can't speak for cheap machines -- I bought mine before DIY SDS drills existed.

IME, using hammer action doesn't improve cutting performance enough to compensate for the damage it does you, and possibly the wall too.

I was also somewhat disappointed how few holes one of these cuts before going blunt.

And definately needs a drill with safety clutch.

[Doctor Drivel]

That may depend on the quality of the TCT core drill bit. Diamond core drill bits are very expensive and require a dedicated core drill to use them. It all comes down to how much TCT bit costs and how many holes you can get out of them. It "may" work out cheaper using a throw-away TCT bit and SDS rather than diamond core.