[time-nuts] Machining some aluminum help!

[Joseph Gwinn]

On Sat, 29 Jul 2017 22:49:10 -0400, time-nuts-request at febo.com wrote:
> 
> ------------------------------
> 
> Message: 2
> Date: Sat, 29 Jul 2017 20:57:56 -0400
> From: Scott McGrath <scmcgrath at gmail.com>
> To: Discussion of precise time and frequency measurement
> 	<time-nuts at febo.com>
> Subject: Re: [time-nuts] Machining some aluminum help!
> Message-ID: <F4DD2BEC-D51D-43B2-93F3-28A57CD6E8B4 at gmail.com>
> Content-Type: text/plain;	charset=us-ascii
> 
> Kerosine is a better tap lube for Aluminum as it is more persistent 
> and less flammable

NO.  Kerosene is *not* a good lubricant for _forming_ taps.

Kerosene (WD-40) and alcohol are good lubricants for _cutting_.

For _forming_, one needs something very viscous, something that 
lubricates at very high pressures, at the yield strength of the 
material being formed.

Joe Gwinn


 
> Content by Scott
> Typos by Siri
> 
>> On Jul 29, 2017, at 6:41 PM, Joseph Gwinn <joegwinn at comcast.net> wrote:
>> 
>>> On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-request at febo.com wrote:
>>> Send time-nuts mailing list submissions to
>>>    time-nuts at febo.com
>>> 
>>> Message: 7
>>> Date: Fri, 28 Jul 2017 14:11:09 -0700
>>> From: "Gary E. Miller" <gem at rellim.com>
>>> To: Discussion of precise time and frequency measurement
>>>    <time-nuts at febo.com>
>>> Subject: Re: [time-nuts] Machining some aluminum help!
>>> Message-ID: <20170728141109.71aad750 at spidey.rellim.com>
>>> Content-Type: text/plain; charset="utf-8"
>>> 
>>> Yo cdelect at juno.com!
>>> 
>>> On Fri, 28 Jul 2017 12:46:30 -0700
>>> <cdelect at juno.com> wrote:
>>> 
>>>> After mounting the tap in the drill
>>>> press and putting a dab of Crisco on the tap I was able to tap each
>>>> hole to a depth of 7/16" as fast as I could turn the handwheel!
>>> 
>>> 
>>> Cool!
>>> 
>>> I suggest you get some real cutting fluid.  The threads will be smoother.
>> 
>> I second that.  What I use is a lubricant wax made by Lenox, the saw 
>> maker.  It's intended for metal-cutting band saws, but works just 
>> splendid for form taps.  There are many equivalents.
>> 
>> By the way, when drilling aluminum, use denatured alcohol as the 
>> cutting fluid.  This will prevent aluminum gumming up the cutting edge 
>> of the drill.
>> 
>> And, as others have mentioned, one does not use the same size drill for 
>> forming taps as for cutting taps.  The diameter accuracy required can 
>> only be achieved by using the correct number (versus fractional) drill 
>> bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
>> Japan, Germany et al are OK.
>> 
>> Joe Gwinn
>> 
>> 
>>> RGDS
>>> GARY
>>> 
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> 
> End of time-nuts Digest, Vol 156, Issue 38
> ******************************************