What kind of screws should I use to connect a metal bracket to 3/4"-thick particle board?

(The original screws are blunt -- they are not pointed (like a wood-screw) -- and the threads look more parallel than angled).

How do I drill pilot holes for the new screws?

http://www.spax.us/


"gary" a écrit dans le message de
...
What kind of screws should I use to connect a metal bracket to 3/4"-thick
particle board?

(The original screws are blunt -- they are not pointed (like a
wood-screw) -- and the threads look more parallel than angled).

How do I drill pilot holes for the new screws?

On 7/11/2015 12:21 AM, gary wrote:
What kind of screws should I use to connect a metal bracket to 3/4"-thick particle board?

(The original screws are blunt -- they are not pointed (like a wood-screw) -- and the threads look more parallel than angled).

How do I drill pilot holes for the new screws?


Not a normal wood screw,

Melamine, particle board, and MDF (medium density fiberboard)



http://www.woodcraft.com/product/149....QyVH1adx.dpuf

The SPAX® MDF SCREWS are too long. They're 1 1/2" and 1 3/4" inches long but my particle board is only 3/4" thick.

The screw I need will go through one "leg" of a "C"-bracket and into a 3/4" thick particle board (without going through the board,

The 5mm x 40mm screws your recommend have nominal length of 1 1/2" for use with 1/2" thick materials.

In article ,
says...

The screw I need will go through one "leg" of a "C"-bracket and into a 3/4" thick particle board (without going through the board,

The 5mm x 40mm screws your recommend have nominal length of 1 1/2" for use with 1/2" thick materials.

Personally I'd through-bolt it--if the other side has to be flat I'd use
flat-head machine screws.

But if it absolutely has to be a blind hole, your best bet is probably
to use something like these:

http://www.mcmaster.com/#92105a016/=y08q4e

Note that they come in different lengths and diameters and in several
styles.

One leg of the "C"-bracket is screwed into the bottom of a pull-out keyboard shelf. The other leg of the bracket is screwed into the bottom of the desk top. The shelf and the desk top are each 3/4"-inch thick.

The screws cannot go all the way through the shelf or the desktop.

gary wrote in
:

One leg of the "C"-bracket is screwed into the bottom of a pull-out
keyboard shelf. The other leg of the bracket is screwed into the
bottom of the desk top. The shelf and the desk top are each 3/4"-inch
thick.

The screws cannot go all the way through the shelf or the desktop.

The shelf isn't a problem, since gravity will hold it on the
bracket and the screws just need to stop it sliding around,
you could use most any screws there.

The top is a problem since gravity is going to pull the screws
out of the top. There are no screws which will work for that
application, particle board is simply too weak to hold a screw
in that orientation. Your solution is to replace the top with
a material more suitable for the purpose.

John

On Fri, 10 Jul 2015 22:21:49 -0700 (PDT), gary
wrote:

What kind of screws should I use to connect a metal bracket to 3/4"-thick particle board?

(The original screws are blunt -- they are not pointed (like a wood-screw) -- and the threads look more parallel than angled).

How do I drill pilot holes for the new screws?


In this application screws will definitely not work. You will need to
use an adhesive. Another alternative would be to add additional
structure.

On 7/11/2015 9:25 AM, gary wrote:
The screw I need will go through one "leg" of a "C"-bracket and into a 3/4" thick particle board (without going through the board,

The 5mm x 40mm screws your recommend have nominal length of 1 1/2" for use with 1/2" thick materials.


What I was recommending was confirmat screws and drill bits for these
screws. They come in all sizes.

I figured you would be able to determine the correct length, I was not
suggesting any particular length, just answering the questions that you
asked.

John McCoy wrote:
gary wrote in
:

One leg of the "C"-bracket is screwed into the bottom of a pull-out
keyboard shelf. The other leg of the bracket is screwed into the
bottom of the desk top. The shelf and the desk top are each
3/4"-inch thick.

The screws cannot go all the way through the shelf or the desktop.

The shelf isn't a problem, since gravity will hold it on the
bracket and the screws just need to stop it sliding around,
you could use most any screws there.

The top is a problem since gravity is going to pull the screws
out of the top. There are no screws which will work for that
application, particle board is simply too weak to hold a screw
in that orientation. Your solution is to replace the top with
a material more suitable for the purpose.

John

I disagree John. While I do agree that particle board is a crummy material
to try to screw into. for the application, a decent sheet metal screw will
probably hold things in place for years, as long as the use of the drawer is
not rough. The thing is that you can't over torque the screws when putting
them in. It's easy to strip the hole and then the holding power is greatly
diminished. Would have been better though if the top were not made of
particle board.

--

-Mike-

John McCoy wrote:
gary wrote in
:

One leg of the "C"-bracket is screwed into the bottom of a pull-out
keyboard shelf. The other leg of the bracket is screwed into the
bottom of the desk top. The shelf and the desk top are each
3/4"-inch thick.

The screws cannot go all the way through the shelf or the desktop.

The shelf isn't a problem, since gravity will hold it on the
bracket and the screws just need to stop it sliding around,
you could use most any screws there.

The top is a problem since gravity is going to pull the screws
out of the top. There are no screws which will work for that
application, particle board is simply too weak to hold a screw
in that orientation. Your solution is to replace the top with
a material more suitable for the purpose.

Or - possibly - to glue a piece of wood to it.

"dadiOH" wrote in :

The top is a problem since gravity is going to pull the screws
out of the top. There are no screws which will work for that
application, particle board is simply too weak to hold a screw
in that orientation. Your solution is to replace the top with
a material more suitable for the purpose.

Or - possibly - to glue a piece of wood to it.

That would probably work. Or you might be able to squirt
epoxy in the hole and strengthen the particle board some
to hold threads. Or perhaps use the kind of EZ-Lok threaded
inserts that have deep threads, and spread the load over
more volume.

But really, particle board is the wrong material if the OP
needs to fasten into the face of it. Running screws into
particle board only works if you're going into an edge - it's
not a coincidence that all the screws are 1.5 inch long or
more, they're intended to go deep into an edge.

John

A computer keyboard and a mouse sits on the shelf that gets pulled-out and pushed-in many times every use.

On Sat, 11 Jul 2015 14:21:15 -0700 (PDT), gary
wrote:

A computer keyboard and a mouse sits on the shelf that gets pulled-out and pushed-in many times every use.

It sounds like you have a very cheap piece of furniture. The best
solution may be to scrap the whole thing and start over with something
higher quality.

"Euro Screws"or "Blum System Screws" from Lee Valley. Same sharp thread like on a Confirmat.

I actually (finally) located one of the original screws.

It's a "Euro Screw":

http://media.allfasteners.com.au/ima...062-2163-1.jpg

Are these screws available at Home Depot or Lowes? (I need only 8 screws).

But really, particle board is the wrong material if the OP
needs to fasten into the face of it. Running screws into
particle board only works if you're going into an edge - it's
not a coincidence that all the screws are 1.5 inch long or
more, they're intended to go deep into an edge.


This is the complete opposite of the facts. You can buy particle board screws from 1/2 inch long. Screws for the edge of particle board are called "carcase" screws, and have a coarser thread than normal P.B. screws. This is because it is very hard to get a good fixing in the edge of P.B.
Have you ever seen P.B.?

gary wrote:
I actually (finally) located one of the original screws.

It's a "Euro Screw":

http://media.allfasteners.com.au/ima...062-2163-1.jpg

Are these screws available at Home Depot or Lowes? (I need only 8
screws).

Did you look on their web sites?

--

-Mike-

Neither Lowes' nor Home Depot's websites list "Euro Screws" but both stores are within 3 miles of my house so I went to Lowes.

The manager of Lowes' hardware department said they don't carry "Euro Screws" and he said they had no other "fasteners" that would work for my situation (i.e., the fasteners on underside of a particle-board desktop that would resist the downward force from the slide-out keyboard shelf on brackets below the desk top).

I then found EZ-Lok threaded inserts on Amazon for $5.00 and added that item to another item I ordered two days earlier so the shipping was FREE for both items.

Neither Lowes' nor Home Depot's websites list "Euro Screws" but both stores are within 3 miles of my house so I went to Lowes.

The manager of Lowes' hardware department said they don't carry "Euro Screws" and he said they had no other "fasteners" that would work for my situation (i.e., the fasteners being attached to the underside of a particle-board desktop that would resist the downward force from the slide-out keyboard shelf on brackets below the desk top).

I then found EZ-Lok threaded inserts on Amazon for $5.00 and added that item to another item I ordered two days earlier so the shipping was FREE for both items.

Neither Lowes' nor Home Depot's websites list "Euro Screws". But since both stores are within 3 miles of my house, I went to Lowes.

The manager of Lowes' hardware department said they don't carry "Euro Screws" and he said they had no other "fasteners" that would work for my situation (i.e., the fasteners being attached to the underside of a particle-board desktop that would resist the downward force from the slide-out keyboard shelf on brackets below the desk top).

I then found EZ-Lok threaded inserts on Amazon for $5.00 and added that item to another item I ordered two days earlier so the shipping was FREE for both items.

On Sun, 12 Jul 2015 15:30:42 -0700 (PDT), gary
wrote:

Neither Lowes' nor Home Depot's websites list "Euro Screws". But since both stores are within 3 miles of my house, I went to Lowes.

The manager of Lowes' hardware department said they don't carry "Euro Screws" and he said they had no other "fasteners" that would work for my situation (i.e., the fasteners being attached to the underside of a particle-board desktop that would resist the downward force from the slide-out keyboard shelf on brackets below the desk top).

I then found EZ-Lok threaded inserts on Amazon for $5.00 and added that item to another item I ordered two days earlier so the shipping was FREE for both items.

Both Lowes and the BORG carry threaded inserts here. They may not be
optimized for particle board but they work (they probably have ones
intended for PB in their furniture hardware section).

In article , krw
wrote:

On Sun, 12 Jul 2015 15:30:42 -0700 (PDT), gary
wrote:

Neither Lowes' nor Home Depot's websites list "Euro Screws". But since both
stores are within 3 miles of my house, I went to Lowes.

The manager of Lowes' hardware department said they don't carry "Euro
Screws" and he said they had no other "fasteners" that would work for my
situation (i.e., the fasteners being attached to the underside of a
particle-board desktop that would resist the downward force from the
slide-out keyboard shelf on brackets below the desk top).

I then found EZ-Lok threaded inserts on Amazon for $5.00 and added that item
to another item I ordered two days earlier so the shipping was FREE for both
items.

Both Lowes and the BORG carry threaded inserts here. They may not be
optimized for particle board but they work (they probably have ones
intended for PB in their furniture hardware section).

This is what cross dowel nuts are for:

..http://www.amazon.com/Buildyourcnc-Cross-Dowels-8-pack/dp/B001DSXTJ2

Joe Gwinn

A cross dowel is used to join two pieces of wood. That's not what I needed to do.

In article ,
gary wrote:

A cross dowel is used to join two pieces of wood. That's not what I needed
to do.

The issue was how to get strong threads in particle board. Cross
dowels are used for this, in lots of cheap furniture.

Joe Gwinn

Cross dowels (with connector bolts) are used to make strong joints when two pieces of wood are joined at a right angle.

But I need a way to attach a bracket to the face of a particle board so the screws don't pull out of the particle board.

gary wrote:
Cross dowels (with connector bolts) are used to make strong joints
when two pieces of wood are joined at a right angle.

But I need a way to attach a bracket to the face of a particle board
so the screws don't pull out of the particle board.

I remain unconvinced that sheet metal screws will not serve the purpose.
The weight of the tray and the keyboard should present no challenge to a
properly sized set of screws. Most of the pull on those screws is going to
be perpendicular to the threads, and at that, it's going to be a very low
amount of force. I'm just not convinced that you have such a big problem
here.

--

-Mike-

I already tried sheet metal screws but they just pulled out of the particle board under normal "keyboarding".

On Monday, July 13, 2015 at 3:37:28 PM UTC-4, gary wrote:
I already tried sheet metal screws but they just pulled out of the particle board under normal "keyboarding".

New holes or the existing (and probably) larger holes from the original euro screws?

If you used the original holes without any filler, I'm not at all surprised that they pulled out.

BTW, you could use elevator bolts flush mounted through the top and call it a "design feature". ;-)

This one is silver, but they come in black and bronze colors also:

http://www.yorkfasteners.com/images/...atorBoltsL.jpg

In article ,
says...

In article ,
gary wrote:

A cross dowel is used to join two pieces of wood. That's not what I needed
to do.

The issue was how to get strong threads in particle board. Cross
dowels are used for this, in lots of cheap furniture.

Joe Gwinn

While they are how do you get them in place in an existing desktop?

gary wrote:

I already tried sheet metal screws but they just pulled out of the
particle board under normal "keyboarding".

That quite surprises me. Did you use large enough screws? I've used this
type of fastener in similar situations many times and have had no problems.
If you used a proper sized sheet metal screw, pulling out and pushing in a
keyboard drawer should not have been a problem at all. I'm guessing you did
something wrong.

--

-Mike-

gary wrote:

I already tried sheet metal screws but they just pulled out of the
particle board under normal "keyboarding".

Another thought - particle board is commonly used for counter tops and is
secured by screws up into the particle board, through angle brackets in the
lower cupboards. They withstand years of moisture, etc. Granted - they are
not subject to a drawer sliding, but I just honestly do not believe a well
mounted drawer slide is going to present a problem.

--

-Mike-

In article , J.
Clarke wrote:

In article ,
says...

In article ,
gary wrote:

A cross dowel is used to join two pieces of wood. That's not what I
needed
to do.

The issue was how to get strong threads in particle board. Cross
dowels are used for this, in lots of cheap furniture.

Joe Gwinn

While they are how do you get them in place in an existing desktop?

I don't have a drawing of the desktop, but assume that one can drill
holes.

Alternately, I've used a bit of sheet metal with threaded holes and a
machine screw from the other side.

Particle board just isn't that good a material for wood screws and the
like.

Joe Gwinn

On Mon, 13 Jul 2015 18:17:12 -0400, "J. Clarke"
wrote:

In article ,
says...

In article ,
gary wrote:

A cross dowel is used to join two pieces of wood. That's not what I needed
to do.

The issue was how to get strong threads in particle board. Cross
dowels are used for this, in lots of cheap furniture.

Joe Gwinn

While they are how do you get them in place in an existing desktop?

With a drill? Not sure what your question really is here.

"Mike Marlow" wrote in
:

If you used a proper sized sheet metal screw, pulling out
and pushing in a keyboard drawer should not have been a problem at
all. I'm guessing you did something wrong.

I think he's saying that working the keyboard, not pushing
the drawer in and out, is the problem. Perhaps he's an
excitable typist, and pounds the keyboard :-)

John

I drilled new holes for the sheet metal screws. The sheet metal screws were the size of the holes in the bracket.

Elevator bolts: I don't want to drill the holes all the way through the particle board.

The screws pulled out of the particle board when I was typing (not when sliding the keyboard shelf in and out).

I drilled new holes for the sheet metal screws. The sheet metal screws were 5/8" long and 3/16" in diameter O.D.

The screws pulled out of the particle board when I was typing (not when sliding the keyboard shelf in and out).

Elevator bolts: I don't want to drill the holes all the way through the particle board.





















Melamine, particle board, and MDF (medium density fiberboard)



http://www.woodcraft.com/product/149....QyVH1adx.dpuf

gary wrote in
:

I drilled new holes for the sheet metal screws. The sheet metal
screws were the size of the holes in the bracket.

Elevator bolts: I don't want to drill the holes all the way
through the particle board.

The screws pulled out of the particle board when I was typing (not
when sliding the keyboard shelf in and out).

Don't predrill, just put the screw in. Sheet metal screws usually have
pretty decent heads, so they're easy to start with the appropriate
screwdriver. (If you're using Phillips head screws, make sure you have the
right size. It will likely be a #2. To check, put the screw on the driver
and try to wiggle it around. If it moves easily, the driver is too small.)

Puckdropper
--
Make it to fit, don't make it fit.

In article ,
says...

On Mon, 13 Jul 2015 18:17:12 -0400, "J. Clarke"
wrote:

In article ,
says...

In article ,
gary wrote:

A cross dowel is used to join two pieces of wood. That's not what I needed
to do.

The issue was how to get strong threads in particle board. Cross
dowels are used for this, in lots of cheap furniture.

Joe Gwinn

While they are how do you get them in place in an existing desktop?

With a drill? Not sure what your question really is here.

He's fastening a keyboard drawer to the bottom of a desktop. That
typically means that he needs four fasteners, two near the edge and two
6-12 inches from the edge. Are you proposing that he manage somehow to
drill a straight 12-inch deep hole into an existing particle board
desktop from the edge, so as to put in the cross-dowel? If not, then
what are you proposing?

And if he objects to fasteners showing on the top of the desk, do you
really thing that holes drilled in the edge are going to be any more
acceptable?