[Sigia-l] Screws

[Boniface Lau]

> From: Eric Scheid
> 
> Before his innovations, his screws were manufactured in accordance
> with the various standards. After his innovations, his new screws
> were still manufactured in accordance with the various standards.

>From http://www.wired.com/wired/archive/10.01/standards_pr.html:

Wired> In cross section, virtually all screw threads were triangular,
Wired> but the particulars of that triangle were matters of intense
Wired> debate. The two sides of a Whitworth thread formed an angle of
Wired> 55 degrees, and its tip was rounded off at the top. The Sellers
Wired> thread, by contrast, had a 60-degree angle, but its apex was
Wired> flattened. 
Wired>
Wired> These differences may sound minor, but in practical terms they
Wired> were revolutionary. 


>From http://www.forbes.com/forbes/2005/0919/066_print.html:

Forbes> Last year ITW introduced a plastic fastener that it calls the
Forbes> BosScrew. Its threads have tiny notches on their upper
Forbes> surfaces that grab the plastic before it can slide down the
Forbes> helix. 


Thus, I would not say the new screws are "still manufactured in
accordance with the various standards."


Boniface