[time-nuts] Machining some aluminum help!

[jimlux]

On 5/18/17 11:53 AM, jimlux wrote:
> On 5/18/17 11:16 AM, Tim Shoppa wrote:
>> I'm very dubious that you need a tapped 4-40 hole to be threaded any
>> deeper
>> than 0.25". If you work with the machinist I'm sure you can come up with
>> some reasonable spec that does not require a bottoming tap and will save
>> you a lot of money.

Fixing the table formatting
>
>                 Threads            Fastener
> Engaged Length    0.125 in
> TPI                  40
> Diameter          0.112 in
> mean Diam        0.0995 in     Root Diam    0.087 in
> Engaged area     0.0391 sq in  Area       0.00594 sq in
> Load                200 lb
> Shear stress      5,119 psi    Stress      33,644 psi
> Ultimate strength    42 ksi    ultimate        74 ksi
> Shear Strength   24,249 psi    proof       55,000 psi
> Safety factor      4.74        Safety factor     1.63
>
>                     Aluminum            Steel
>
>