(In the spirit of "It's better to ask a stupid question than to make a
stupid mistake...)
These two screws are both sold as 4mm:
https://plus.google.com/photos/112724770564213352605/albums/5896168001404313601?authkey=CLGTvbqC-5LWMQ
(links to four pictures, showing measurements on digital caliper of
shaft & thread for each of the two screws. Hosted by google, no adverts
other than what google stick in, if any)
Am I right in my understanding that 4mm is the maximum size of the thread
diameter, i.e. they are likely to be smaller than this measurement, but
they will not be bigger?
Secondly, for a pilot hole, I understand that the drill bit used should be
the diameter of the shat of the screw, so it is basically the threads that
are biting into the wood fibres and the screw shaft is not having to be forced
in. But as the photo's show, the shafts are not of an available drill size so
it is better to go for the next drill size up or down? Or round up or down
either side of the half measurement?
Sorry if these questions seem trivial to you all, but this sort of thing
gnaws away at the back of my mind, so it's nice to get some professional
input!
Thanks in advance,
David Paste.
On Wednesday, July 3, 2013 3:40:29 AM UTC-7, SBH wrote:
> On 7/2/2013 8:00 PM, [email protected] wrote:
>
> > (In the spirit of "It's better to ask a stupid question than to make a
>
> > stupid mistake...)
>
> >
>
> > These two screws are both sold as 4mm:
>
> >
>
> > https://plus.google.com/photos/112724770564213352605/albums/5896168001404313601?authkey=CLGTvbqC-5LWMQ
>
> >
>
> > (links to four pictures, showing measurements on digital caliper of
>
> > shaft & thread for each of the two screws. Hosted by google, no adverts
>
> > other than what google stick in, if any)
>
> >
>
> > Am I right in my understanding that 4mm is the maximum size of the thread
>
> > diameter, i.e. they are likely to be smaller than this measurement, but
>
> > they will not be bigger?
>
> >
>
> > Secondly, for a pilot hole, I understand that the drill bit used should be
>
> > the diameter of the shat of the screw, so it is basically the threads that
>
> > are biting into the wood fibres and the screw shaft is not having to be forced
>
> > in. But as the photo's show, the shafts are not of an available drill size so
>
> > it is better to go for the next drill size up or down? Or round up or down
>
> > either side of the half measurement?
>
> >
>
> > Sorry if these questions seem trivial to you all, but this sort of thing
>
> > gnaws away at the back of my mind, so it's nice to get some professional
>
> > input!
>
> >
>
> > Thanks in advance,
>
> >
>
> > David Paste.
>
> >
>
> The size of a screw is determined by it's complete diameter, including
>
> thread. If they are smaller, then it's not really what it's supposed to
>
> be, is it.
>
>
>
> Drill size is always smaller unless you have no intentions of biting
>
> into the material. For example, if fastening a mount to an engine block,
>
> the holes for the mount would be larger than the screw, but bite into
>
> the block to draw the mount into the block. Of course, this is using a
>
> machine screw, but the same concept applies even with wood screws.
>
>
>
> I can assure you, there is a proper drill size for your need, you simply
>
> may not have it. If not, go one smaller. The main objective is to
>
> eliminate splitting/tearing of the wood. Even a smaller pilot hole will
>
> eliminate splitting. If you go larger, you risk less biting and thus,
>
> the screw would be more prone to loosen.
1+ What he said.
Although when I read the headline question I assumed the answer would be "lay her on her back, climb on and get to it."
Read
http://en.wikipedia.org/wiki/Screw
all (or almost all) your questions will be answered.
ck
<[email protected]> a écrit dans le message de
news:[email protected]...
> (In the spirit of "It's better to ask a stupid question than to make a
> stupid mistake...)
>
> These two screws are both sold as 4mm:
>
> https://plus.google.com/photos/112724770564213352605/albums/5896168001404313601?authkey=CLGTvbqC-5LWMQ
>
> (links to four pictures, showing measurements on digital caliper of
> shaft & thread for each of the two screws. Hosted by google, no adverts
> other than what google stick in, if any)
>
> Am I right in my understanding that 4mm is the maximum size of the thread
> diameter, i.e. they are likely to be smaller than this measurement, but
> they will not be bigger?
>
> Secondly, for a pilot hole, I understand that the drill bit used should be
> the diameter of the shat of the screw, so it is basically the threads that
> are biting into the wood fibres and the screw shaft is not having to be
> forced
> in. But as the photo's show, the shafts are not of an available drill size
> so
> it is better to go for the next drill size up or down? Or round up or down
> either side of the half measurement?
>
> Sorry if these questions seem trivial to you all, but this sort of thing
> gnaws away at the back of my mind, so it's nice to get some professional
> input!
>
> Thanks in advance,
>
> David Paste.
On 7/3/2013 12:27 PM, SonomaProducts.com wrote:
> On Wednesday, July 3, 2013 3:40:29 AM UTC-7, SBH wrote:
>> On 7/2/2013 8:00 PM, [email protected] wrote:
>>
>>> (In the spirit of "It's better to ask a stupid question than to make a
>>
>>> stupid mistake...)
>>
>>>
>>
>>> These two screws are both sold as 4mm:
>>
>>>
>>
>>> https://plus.google.com/photos/112724770564213352605/albums/5896168001404313601?authkey=CLGTvbqC-5LWMQ
>>
>>>
>>
>>> (links to four pictures, showing measurements on digital caliper of
>>
>>> shaft & thread for each of the two screws. Hosted by google, no adverts
>>
>>> other than what google stick in, if any)
>>
>>>
>>
>>> Am I right in my understanding that 4mm is the maximum size of the thread
>>
>>> diameter, i.e. they are likely to be smaller than this measurement, but
>>
>>> they will not be bigger?
>>
>>>
>>
>>> Secondly, for a pilot hole, I understand that the drill bit used should be
>>
>>> the diameter of the shat of the screw, so it is basically the threads that
>>
>>> are biting into the wood fibres and the screw shaft is not having to be forced
>>
>>> in. But as the photo's show, the shafts are not of an available drill size so
>>
>>> it is better to go for the next drill size up or down? Or round up or down
>>
>>> either side of the half measurement?
>>
>>>
>>
>>> Sorry if these questions seem trivial to you all, but this sort of thing
>>
>>> gnaws away at the back of my mind, so it's nice to get some professional
>>
>>> input!
>>
>>>
>>
>>> Thanks in advance,
>>
>>>
>>
>>> David Paste.
>>
>>>
>>
>> The size of a screw is determined by it's complete diameter, including
>>
>> thread. If they are smaller, then it's not really what it's supposed to
>>
>> be, is it.
>>
>>
>>
>> Drill size is always smaller unless you have no intentions of biting
>>
>> into the material. For example, if fastening a mount to an engine block,
>>
>> the holes for the mount would be larger than the screw, but bite into
>>
>> the block to draw the mount into the block. Of course, this is using a
>>
>> machine screw, but the same concept applies even with wood screws.
>>
>>
>>
>> I can assure you, there is a proper drill size for your need, you simply
>>
>> may not have it. If not, go one smaller. The main objective is to
>>
>> eliminate splitting/tearing of the wood. Even a smaller pilot hole will
>>
>> eliminate splitting. If you go larger, you risk less biting and thus,
>>
>> the screw would be more prone to loosen.
>
> 1+ What he said.
>
> Although when I read the headline question I assumed the answer would be "lay her on her back, climb on and get to it."
>
The 3.91 can arguably be called 4mm, the 3.7 NOT.
I think if you used the thick part of the jaws to measure the threads
near the head you might be closer to 4mm..
That's just my opinion, not based on any formal knowledge.
--
Jeff
On Tuesday, July 2, 2013 6:00:07 PM UTC-6, [email protected] wrote:
> (In the spirit of "It's better to ask a stupid question than to make a st=
upid mistake...) These two screws are both sold as 4mm: https://plus.google=
.com/photos/112724770564213352605/albums/5896168001404313601?authkey=3DCLGT=
vbqC-5LWMQ (links to four pictures, showing measurements on digital caliper=
of shaft & thread for each of the two screws. Hosted by google, no adverts=
other than what google stick in, if any) Am I right in my understanding th=
at 4mm is the maximum size of the thread diameter, i.e. they are likely to =
be smaller than this measurement, but they will not be bigger? Secondly, fo=
r a pilot hole, I understand that the drill bit used should be the diameter=
of the shat of the screw, so it is basically the threads that are biting i=
nto the wood fibres and the screw shaft is not having to be forced in. But =
as the photo's show, the shafts are not of an available drill size so it is=
better to go for the next drill size up or down? Or round up or down eithe=
r side of the half measurement? Sorry if these questions seem trivial to yo=
u all, but this sort of thing gnaws away at the back of my mind, so it's ni=
ce to get some professional input! Thanks in advance, David Paste.
Quick tip for attaching two pieces of wood together, drill the pilot hole o=
n the board farthest from the head of the screw,with a drill bit that is sm=
aller than the diameter of the screw. I usually go with a drill bit as clo=
se to the shaft (minus teeth)as possible without going over it. Drill the =
pilot hole of the board nearest the head of the screw with a drill bit that=
is the diameter of the teeth of the screw. This way when you screwing in =
the screw, the screw will float thru the first board and grab the second bo=
ard, thus creating a tighter joint.
On 7/2/2013 8:00 PM, [email protected] wrote:
> (In the spirit of "It's better to ask a stupid question than to make a
> stupid mistake...)
>
> These two screws are both sold as 4mm:
>
> https://plus.google.com/photos/112724770564213352605/albums/5896168001404313601?authkey=CLGTvbqC-5LWMQ
>
> (links to four pictures, showing measurements on digital caliper of
> shaft & thread for each of the two screws. Hosted by google, no adverts
> other than what google stick in, if any)
>
> Am I right in my understanding that 4mm is the maximum size of the thread
> diameter, i.e. they are likely to be smaller than this measurement, but
> they will not be bigger?
>
> Secondly, for a pilot hole, I understand that the drill bit used should be
> the diameter of the shat of the screw, so it is basically the threads that
> are biting into the wood fibres and the screw shaft is not having to be forced
> in. But as the photo's show, the shafts are not of an available drill size so
> it is better to go for the next drill size up or down? Or round up or down
> either side of the half measurement?
>
> Sorry if these questions seem trivial to you all, but this sort of thing
> gnaws away at the back of my mind, so it's nice to get some professional
> input!
>
> Thanks in advance,
>
> David Paste.
>
The size of a screw is determined by it's complete diameter, including
thread. If they are smaller, then it's not really what it's supposed to
be, is it.
Drill size is always smaller unless you have no intentions of biting
into the material. For example, if fastening a mount to an engine block,
the holes for the mount would be larger than the screw, but bite into
the block to draw the mount into the block. Of course, this is using a
machine screw, but the same concept applies even with wood screws.
I can assure you, there is a proper drill size for your need, you simply
may not have it. If not, go one smaller. The main objective is to
eliminate splitting/tearing of the wood. Even a smaller pilot hole will
eliminate splitting. If you go larger, you risk less biting and thus,
the screw would be more prone to loosen.
On Tue, 2 Jul 2013 17:00:07 -0700 (PDT), [email protected] wrote:
>(In the spirit of "It's better to ask a stupid question than to make a
>stupid mistake...)
>
>These two screws are both sold as 4mm:
>
>https://plus.google.com/photos/112724770564213352605/albums/5896168001404313601?authkey=CLGTvbqC-5LWMQ
>
>(links to four pictures, showing measurements on digital caliper of
>shaft & thread for each of the two screws. Hosted by google, no adverts
>other than what google stick in, if any)
>
>Am I right in my understanding that 4mm is the maximum size of the thread
>diameter, i.e. they are likely to be smaller than this measurement, but
>they will not be bigger?
>
>Secondly, for a pilot hole, I understand that the drill bit used should be
>the diameter of the shat of the screw, so it is basically the threads that
>are biting into the wood fibres and the screw shaft is not having to be forced
>in. But as the photo's show, the shafts are not of an available drill size so
>it is better to go for the next drill size up or down? Or round up or down
>either side of the half measurement?
>
>Sorry if these questions seem trivial to you all, but this sort of thing
>gnaws away at the back of my mind, so it's nice to get some professional
>input!
>
>Thanks in advance,
>
>David Paste.
To answer your first question, yes.
For your second question, yes, but it's slightly more complicated than
that. McFeely's is an excellent fastener supplier and has a good
explanation of pilot hole sizes. I'm sure there are other sites that
will support their information as well as others that will dispute it.
YMMV.
http://www.mcfeelys.com/tech/wadb.htm