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Re: [TowerTalk] Drill bits

To: "Tower and HF antenna construction topics." <>
Subject: Re: [TowerTalk] Drill bits
From: Charlie Gallo <>
Reply-to: Charlie Gallo <>, "Tower and HF antenna construction topics." <>
Date: Wed, 24 Mar 2010 13:35:38 -0400
List-post: <">>
On 3/24/2010 Jack Brindle wrote:

> . I prefer titanium bits - they don't  
> cost much more, but last quite a bit longer than HSS.

"Titanium" bits

1st - they are not "titanium" - they are bits that have been coated with 
Titanium Nitride  coating  - generally called TiN coating in the industry.  
It's one of many types of coatings used on bits, and perhaps the 

There is one problem. 

As you probably know, drill bits come in a range of quality - ranging from 
cheap junk, typically imported from China/India/Pakistan, up through some 
really really well made US/European made bits (BTW, there are some VERY good 
imported bits out there - not to tar all with the same brush)

The problem is, most that are sold as "Titanium" drill bits are generally VERY 
cheap bits coated with TiN and then sold as "Titanium" bits to folks who don't 
know better - to quote a friend "A golden turn is still a turd"

Now, if you go out, find a place that sells the bits honestly as "TiN coated" - 
generally they are a GOOD bit,  (its that they are selling it as it really is, 
without the hook) 

Now, the Original poster did NOT say how deep a hole he was drilling, or 
exactly what the material is (may not know), so in the following, I'm going to 
assume "jobbers length" (aka what 99% of everyone thinks of drill bits)

Let's assume you want a 135 deg spit point (hey, let's make the guy's life 
easy), and we want a HSS bit with or without a coating

Looking at the MSC web page ( - standard disclaimer applies - 
and they will do a small order  if you ask nice - usual minimum is $25 - ask 
them for a catalog while your at it - expect a VERY big book) I see 17 drill 
bits listed with those parameters, ranging from $2.10, up to $15.60 EACH

A Hertal (a good brand BTW - and right now cheaper than generic 'Made in USA') 
TiN coated bit will run you $8.81 (item number 84579770 )

Now, let's say you want to go up one coating grade - now it won't be a pretty 
gold color anymore, but you'll be up at TiAlN (Titanium aluminum nitride) - now 
you'll be up at like $13-15 a bit!

Thing is, a GOOD quality Hertal NON coated bit will run you, oh, $4.27 or so, 
or a "precision Twist drill (its a brand name)" is going to run $5.33, and they 
will probably hold up BETTER than an import "Titanium" drill

Of course, if he has the machines necessary to hold carbide so it doesn't chip, 
he can always buy a nice solid carbide Kennametal TiAlN coated bit at over $200

So, what's the best drill bit?  

The answer is "It depends" - tell me more about what you're doing, and I might 
be able to guess

73 de KG2V

"But when a long train of abuses and usurpations,
pursuing invariably the same Object evinces
 a design to reduce them under absolute Despotism,
it is their right, it is their duty, to throw off such Government,
 and to provide new Guards for their future security."

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