"Dave Plowman (News)" wrote:
In article ,
wrote:
Well it's really to find out how much torque is needed to screw them
in successfully and how much will break them. I'm looking for a new
cordless driver and want to know what sort of torque figure is useful
and how much is simply too much. The cordless driver specifications
give their maximum torquer but nowhere can I find any figures for how
much torque is actually needed to screw screws in.

Well, all these sort of things have adjustable maximum torque. And on mine
the minimum setting is so low I've never used it.

But I think you're worrying far too much. As I've said, I frequently use a
mains drill as a screwdriver, and it has much more torque than any normal
cordless. This would often be for screwing down floorboards - lots and
lots of 2" 10 pozidriv. And breaking a screw is a rarity. The bit 'cams
out' before this happens.

I'm screwing in 8mm hex head coach screws, nothing 'comes out' in this
case, you have several alternative options:-

The driver runs out of oomph, the usual case until I got my new
Metabo SBT12. I then had to use a spanner to get the screw in the
rest of the way.

The cordless clutch/torque setting starts to slip, this is what
happens on the stiffest setting on the Metabo. It does get the
screw in most of the way before it starts clicking though.

I stop screwing when the screw reaches the right point, generally
possible and this is what I'm doing.

The screw shears if/when I don't stop in time. It hasn't happened
yet with the new Metabo but it would be nice to know if 53Nm is
capable of shearing an 8mm screw.

--
Chris Green