[NLRS] 4-40 tap

[Mike King - KM0T]

I did a bunch of 4-40 tapping as well as a bit bigger stuff for heats sinks, 
using oil.  Boy did that suck, broke off tap bits and all....it was kinda a 
struggle.

Saw a thread a year or so ago about the raves of using soap as the tapping 
lube, man that changed everything...works awesome, never broke a tap after 
that.  (all this tapping al for heatsinks)

73 and GL

Mike- KM0T

----- Original Message ----- 
From: "Charlie Betz" <cbetz at clearwire.net>
To: <W0ZQ at aol.com>; <nlrs at mailman.qth.net>
Sent: Sunday, February 11, 2007 8:14 PM
Subject: Re: *****SPAM***** Re: [NLRS] 4-40 tap


>
>
> John,
>
> Menards sells drill and tap sets, I'm pretty sure down to #4-40.  These 
> are individual cards with tap and appropriate drill for the particular 
> tap. That run $3 - $4.
>
> Jerry mentioned McMaster-Carr.  If you are tapping aluminum, take a look 
> at the spiral fluted taps that they sell.  They are a little more 
> expensive than the standard taps, but made for tapping aluminum.  They do 
> seem to work better than standard taps, but you still need to excerise 
> care as they will break.
>
> Mark, N9LTJ told me about another trick for tapping aluminum that I have 
> not tried, but he says works well.  He says you can rub some bar sap into 
> the hole you are tapping and it will help float the debris out.  You still 
> should lube the tap as well.  As I said, I have never tried this method, 
> but Mark has done lots of metal work in his lifetime, so I trust what he 
> says.
>
> Charlie, N0AKC
>
>
> ----- Original Message ----- 
> From: "Donn Baker" <wa2voi at mail.mninter.net>
> To: <W0ZQ at aol.com>; <nlrs at mailman.qth.net>
> Sent: Sunday, February 11, 2007 7:12 PM
> Subject: *****SPAM***** Re: [NLRS] 4-40 tap
>
>
>>
>>
>> Hi Jon,
>> Any good hardware store should have the common size taps, down to 4-40. 
>> If
>> you don't find a set, you'll need a #43 drill for tapping steel or brass.
>> Like Jerry suggested, a larger drill works better for aluminum, say a #41
>> or #40.
>>
>> Never cut a thread without lubricating the tap, especially in Al.  "Tap
>> Magic" is the best I've seen, but, again as Jerry said, kerosene works
>> well.  Oil does NOT (for Al).  Light oil is for steel or brass.
>>
>> 4-40 taps are quite breakable.  Quite frankly, I'd advise you to buy two
>> while you're at it.  Hub Hobby may have them, but Lowe's, or a hardware
>> store, is a better bet.  You really want "tool steel" for the tap.  A lot
>> of the ones you'll find (especially at Lowe's or hardware stores) will 
>> tend
>> to be "carbon steel."  May be marked that way, or a darker color.  Carbon
>> steel cuts well, but its a lot more brittle than tool steel, and will 
>> break
>> easier.
>>
>> Oh.  If you're going to tap copper, work VERY slowly, use LOTS of fluid;
>> cut maybe 1/4-turn, back off, repeat.  Copper is sticky, and will break
>> taps very, VERY easily. (Experience speaking.  AND its a )*&(&() getting
>> the broken tap out of the hole !  Mostly, you don't.)
>>
>> Lastly, make sure you don't flex the tap.  It needs to be perpendicular 
>> at
>> all times.  You can get away with being sloppy with 10-xx and 8-xx taps;
>> maybe w/6-xx, but not so much 4-xx.  Smaller than 4-40, I do tapping in 
>> the
>> drill press or mill (with out power, of course... just to keep alignment 
>> of
>> the parts).
>>
>> 73 Donn
>> WA2VOI/0
>>
>> At 16:26 11-02-07 EST, W0ZQ at aol.com wrote:
>>>
>>>
>>>Anyone know of a good source for a 4-40 drill  and tap ?   I suppose Hub
>>>Hobby ?   I looked at DigiKey and  did not see a listing for taps.
>>>
>>>73, Jon
>>>W0ZQ
>>>
>>>
>>>Thanks for  your participation in the 2007 MnQP !
>>>
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>>>NLRS at mailman.qth.net
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>>>
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