[GreenKeys] Re: Hold down screws for the M28 or M35 typing unit

Mon, 24 Jun 2002 18:28:41 -0500

fine thread on 1/4 is usually 1/4-28 tom
----- Original Message -----
From: "Don Robert House" <[email protected]>
To: "Ben Stephens" <[email protected]>
Cc: <[email protected]>; "Bob Liddy" <[email protected]>; "Bob
Cnota" <[email protected]>; "Ed Hickey" <[email protected]>; "Ken Clinkman"
<[email protected]>; "Phil Schelinski" <[email protected]>; "Steve
Kissinger" <[email protected]>; "David Weil" <[email protected]>
Sent: Monday, June 24, 2002 6:24 PM
Subject: [GreenKeys] Re: Hold down screws for the M28 or M35 typing unit


> Thanks Ben,  You are absolutely correct.
> Don
>
>
>
> >Comment:  Teletype tended to use National Fine series threads.
> >These have more threads per inch than you would expect in a screw
> >from the hardware store.  For example, we all have tons of  National
> >Coarse (NC) #6-32 screws around.   But Teletype used a #6-40 NF
> >series.  If the mounting screws are 1/4-32, that also is NF.  The
> >usual screw at the hardware store is, I belive a 1/4-20 thread.  I
> >never heard why they used NF screws; I suspect it may have been to
> >keep the screws from loosening under the constant vibration.
> >
> >So be careful to start any unknown screw gently with your fingers,
> >and if it binds up, you may have a NC screw trying to go into a NF
> >tapped hole.=
> >
> >Ben Stephens K9KOM=
> >
>
>
> --
> --------------------------------------------------------
> Don Robert House
> URL: http://www.nadcomm.org
> email: [email protected]
> email: [email protected]
> email: [email protected]
> email: [email protected]
> email: [email protected]
>
>
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