Turbo Coach Screws-not.

[The Medway Handyman]

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!

[robgraham]

I'm using the same coach screws from Screwfix (10x 160mm) and never considered that they could be driven with anything else but the ratchet thingy from my socket set.

When you consider that they are 10mm in diameter then it is hardly reasonable in my reckoning asking an electric screwdriver to put them in - I would actually say that I think Screwfix are being quite reasonable in offering a credit as I think you have translated the advert as you wanted to.

I'm screwing edge on into 100 x 50 softwood and again with that diameter of screw I reckoned that a 5mm pilot hole and lubrication with beeswax was good practice anyway and I've had no difficulties.

Rob

[Alex]

see somebody else thinks you are wanker,

this is a diy group take your for profit questions somewhere else and stop making money from our answers

[dom]

You really expected a 10mm coach screw to self-tap?

I pilot drill anything over 5mm (less in hardwood), and I'm using a cordless impact driver to drive them home.

[Dave Plowman (News)]

I'm not surprised at 10mm diameter. Most drills will struggle with screws half that size without a pilot.

[boltmail]

I've used these (150mm x 10mm ones) and my elu 12v impact driver put them into softwood fine without a pilot hole.

[dom]

That's good going, even for an impact driver. You're pushing the whole150mm into the timber?

I use 6x100m and similar turbogold a lot, mostly in mahogany or oak, predrill at 3-4mm (with a clearance hole in the attached timber) and my

14.4v bosch impact driver can start to slow. Pushing harder than that and it's very possible to snap a screw. Lube helps a bit. 10mm is unlikely to snap, but what about it simply locking solid (and unwilling to reverse out) before fully inserted?

How close to an edge can you go with 10mm, without pre-drilling? Did you lube them? Did you get any cracking along the grain?

[meow2222]

Thats quite a screw.

NT

[dom]

Have a look at how modern timber windows are made. They often scarfe the profiles to each other and use very large screws to secure them - no fancy wood joints. One advantage is that all the parts can be fully treated on all sides before assembly - so the end grain is protected if moisture eventually creeps in.

[The Medway Handyman]

Thank you for your considered and informative opinion.

Were you not of obviously limited intelect you would have noticed that I contribute regularly to this group, especially in areas where I have expertise - like the Pressure Washer FAQ and the soon to be finished Carpet Cleaning FAQ. I don't make a profit when I do this.

And your positive contribution would be?

Oh, I just noticed - bugger all.

Fuckwit

[meow2222]

100m screws may be a little big for that though.

NT

[dom]

The majority of Scandinavian window manufacturers no longer use tenon joints for the sub-frames. The jambs and mullions are end cut to match the sill profile, but the connection often consists of a glued joint and long screws driven through the sill from the underside into the ends of the vertical members. This simplifies manufacture and reduces the length of timber necessary for the vertical members because of the omission of the projecting tenon. These screwed connections are sufficiently strong for handling, and once the sub-frame is installed and fixed, there is little strain on the joints.

[Dave Liquorice]

That's quite a window frame that can take a 100m screw.

[dom]

Damn - has taken me a while to see my typo.

[Bolted]

Yes, of course.

This was softwood, as I deliberately mentioned. I have no doubt it would be a very different story in hardwood. Hang on ...

Right, tried it on a bit of beech - it got about two inches in and seized solid. So I tried it on some softwood to make sure I hadn't just forgotten drilling pilot holes. It worked - I had to to back up a couple of inches about three times to get a 'run-up' and presumably clear the 'drilling' edges (more than I'd remembered doing, although I do recall doing that for last inch or so).

That just happened on the beech - had to use a spanner to free it up.

What I'd previously done was attaching a 3 by 2 to a 4 by 2, through the 2 inch faces, right in the middle. No lube and no cracking. The beech I just did right at the end of a plank, about 15mm in. A crack was developing along the grain.

[Mark]

And you are surprised by this ? You need an impact driver, but not the type you whack on the end with a hammer !

never trust a .................

-

[John]

I've just built a pergola using M8x150 Turbo Coach Screws from Screwfix. They went straight in to treated softwood using a variable speed mains drill. I did final tightening (1/2 turn or so) by hand using a socket & ratchet. No problem there. My cheap 16V battery drill wouldn't look at them but I didn't expect it to. The mains drill did get hot so I had to cool it by either running off load for a minute every couple of screws or arranging my work to give it time between uses. A two speed gearbox driven drill would probably have coped better.

John

[Dan delaMare-Lyon]

Where on earth do you get your luck from Dave? On 8x1.5's from the screwfix ranges that claim no pilot hole all I seem to get is split f**king wood - so much so that I've given up and gone back to Pilot Holes and Quicksilvers....seems that lady luck ain't on my side much ;-)

Cheers Dan.

[The Medway Handyman]

My 500w Skill wouldn't have it. What size drill?

I'll try with my 700w two speed PP and see what happens. Thanks

[John]

An old B&D 500W. D143V, 3000 RPM. I was driving M8 remember so the torque required for M10 is 25% more. Add to that the extra friction due to extra surface area and you may need up to 40% more torque. A gearbox drill should give that though.

John