Faceplate screw strenghts ?

[Wood spinner]

Hi people

Queston the the knowlagable amongst us

Do wood screws come in different strenghts as bolts do ?

I have some rather big lumps of wood and a 8" faceplate , I would like to use the highest strenght screws for obvious reasons 

[fuzzyturns]

Yes, there are some points to notice.
Firstly, do not use your average self-cutting screws. Most of them are made by pressing the material into a shape, and neither that nor the material itself will provide any protection against shearing forces (which is mostly what you get when mounting on a faceplate).
I'd advise you seriously to go and buy some proper steel screws, they will hold against these forces.
Secondly, use the biggest heads you can fit into your face plate. There will be forces at work when the screws get tightened, and smaller heads will either give way or you'll wear out the slots/pozi drives. Again, steel screws will hold out a lot longer.
I think the best solution would be steel hex bolts, i.e. with a hexagonal flat head and washers underneath.

[Wood spinner]

Steel hex bolts ? How do I screw them in ?

[duncanh]

I use hex head stainless steel coach screws as large as will fit through the holes in my faceplate - M8 I think.

Drill a pilot hole and screw in as far as they'll go using a hex socket head in a battery drill, then tighten with a ratchet socket set. Depending on the size and weight of the wood I'll use 4 or 8 screws. Never had anything come loose yet...

[Wood spinner]

OK thanks They look more the part , will measure the face plate holes tomorrow and order a pack of 10 

[Derek]

Whichever screw you use make sure they fit the holes correctly as if they are too small and you get a catch they are more likely to shear as there is movement in the hole

[Sandy]

Hey Wood spinner,  if you're still unsure on your screwing problem, you could always check out Nick Zammeti's youtube to see what he uses

[Wood spinner]

Hey Wood spinner,  if you're still unsure on your screwing problem, you could always check out Nick Zammeti's youtube to see what he uses

Yes good idea , Whoever sponsors him I supose 

[Redtails4]

Hi
Commerical made screws start life has wire and are forged with the grain structure flowing in the same way. The problem is in the Hardening process, the finished screw is left brittle
A classic example of this is the plaster board screw you only have to use it couple of times and and the head drops off.the best screw to use is the stainless it's tough but not hard.
The weakness in most screws is directly under the head.
If you ask for a m8 screw you may get a bolt or a set screw, just ask for coach screws or bolts.

[Paul Hannaby]

I remember in the past many turners recommended the square socket head type screws. I guess the heads are less likely to get chewed up than the cross drive types.

[willstewart]

This is interesting but I wonder if the screw itself failing is very likely (compared to the wood). And I would be careful to use screws with conical (ie countersunk) heads so that these lock in to the conical-topped holes in my faceplate. This may give a firmer fix against transverse forces than the screw in the hole, which is unlikely to be a close fit.

[fuzzyturns]

If you use the wrong type of screw, you are pretty much guaranteed either a breakage or worn-out heads in a very short time. The latter is a nuisance, whereas the former is outright dangerous. Hence the recommendation to use the biggest screws that will fit through the holes.
Use coach screws, and a suitable nut to wind them in and out.

[Lazurus]

If you use the wrong type of screw, you are pretty much guaranteed either a breakage or worn-out heads in a very short time. The latter is a nuisance, whereas the former is outright dangerous. Hence the recommendation to use the biggest screws that will fit through the holes.
Use coach screws, and a suitable nut to wind them in and out.

Don't be afraid to enlarge or add holes to your face plate (s) they are easy to drill just be sensible toward the edges. I have added multiple larger holes to cope with the capacity of the VB - just don't overdue it and risk the integral strength of the face plate. 

[Les Symonds]

This is interesting but I wonder if the screw itself failing is very likely (compared to the wood). And I would be careful to use screws with conical (ie countersunk) heads so that these lock in to the conical-topped holes in my faceplate. This may give a firmer fix against transverse forces than the screw in the hole, which is unlikely to be a close fit.

There is an issue with relying on the conical shape of a countersink to provide a "lock" as you refer to. It is often the case that our wooden blanks are slightly out of true, especially when cut out by chainsaw, in which case there may be a very slight gap between the faceplate and the timber, at certain points. If you get a dig-in, there may be sufficient forces against the face of the blank to press the blank tighter against the faceplate and therefore ease off the pressure on the screw, in which case its countersink will no longer be preventing sideways (rotational) slip. This is not a common occurrence, but one to be aware of.

Les

[Redtails4]

Hi
Concerning screw dimensions and the enlargement of face plate screw holes , colchester lathes used to limit the speed (rpm) because the chucks were made of cast iron and worse case scenario the chucks could break up
Under load.
So i would check what your face plates are made of. If they are of far Eastern manufacture  i would not use them.