What type of screw ?

[mowhoong]

What is the diffrence between a Thread forming screw use on plastic
and metal ?
I can't tell them apart . Can anyone , please enlighten me ?

Thanks in advance

 

[Rich Webb]

On Fri, 3 Jun 2011 01:21:28 -0700 (PDT), mowhoong <mowhoong@hotmail.com>
wrote:

What is the diffrence between a Thread forming screw use on plastic
and metal ?
I can't tell them apart . Can anyone , please enlighten me ?

Some thread-forming screws are appropriate for use on either plastic or
metal, depending on the specifics of the application.

*Generally* sheet metal screws are "pointy" and fasteners intended for
plastic are blunt-nosed with a cutting notch on the end but there are
many variations.

<http://www.mcmaster.com/#tapping-screws/=cl3how>

--
Rich Webb Norfolk, VA

 

[Phil Allison]

"Rich Webb"

*Generally* sheet metal screws are "pointy" and fasteners intended for
plastic are blunt-nosed with a cutting notch on the end but there are
many variations.

** Often thread forming screws for plastic are " twin tread " too.

A real time & motion expert's favourite.....



..... Phil

 

[Jasen Betts]

On 2011-06-03, mowhoong <mowhoong@hotmail.com> wrote:

What is the diffrence between a Thread forming screw use on plastic
and metal ?
I can't tell them apart . Can anyone , please enlighten me ?

screws for plastic have a notch at the tip and a blunt tip.
screws for sheetmetal have a point or a triangular cross-section
screws for thicker steel (over 1mm) have the notch too but are made
of hard steel.

there's a bunch of other thread-forming screws too (like for brick,
and self-drilling for steel sheet )

--
⚂⚃ 100% natural