Pete C wrote:
On Sat, 01 Jul 2006 09:08:27 GMT, "The Medway Handyman"
wrote:

Hi All

Just received some 10 x 100mm Turbo Coach Screws from Screwfix.

The catalogue description reads:
"Make any job faster with Zinc-plated, Yellow-passivated Coach Screws,
combining the unique design of the Turbo Screw along with a self-cutting
point. (May require pilot holes in harder substrates.) Unique Rifled Shank
for Easier Driving & Reduced Splitting, Self-Drilling Point".

You simply cannot drive these into softwood without a large pilot hole!!!!
Let alone 'harder substrates'.

I tried with my 14.4v driver (loads of torque), a 350w mains driver and a
500w variable speed drill. No chance at all, they go in for about an inch
and thats it.

Screwfix have responded to the problem by offering a credit without
collection to be fair to them, but I'm still going to lose time on a large
decking job. I've ordered some 6.3 x 100 Exterior Timber Screws at double
the cost in the hope they will drive OK.

Never trust a catalogue description!

Hi,

Better to drill a pilot hole as any splitting can let in water and the
decking rots from inside.

However few people know this, so you're OK using anything.

cheers,
Pete.


Try soaping the threads first. This usually reduces friction enough for
them to drive straight in.. And use some welly on the screwdriver.

I've found nearly any screw can be whacked through almost anything given
enough torque. The limiting factor is the screw shears or the cross head
rips out. Or both..

If all else fails hammer them in and use a screwdriver on the last few
turns.

Even on hardened oak its normally possible to not use a pilot hole.