John Gonser wrote:
> I found that several of the auger bits (Jennings pattern) that I recently
> purchased are not accurately sized. Anybody know what the size tolerance
> should be for the diameter at the spur and of the auger itself?
No, I don't know but I do know there are ANSI and ISO standards for
twist drills and I presume there would be for other varieties as well.
I'd start looking in those directions if it is really that significant.
Of course, what a Standard says is of no benefit if the manufacturer
isn't following it... :)
Just out of curiousity, what's the application that requires such
precision and what kind of measurements are you getting?
I'm getting 1/32" of error in the spur diameter on some bits and up to 1/16"
( or more) on the auger. This is fairly critical in a 1/4" hole, and it
isn't very good in 3/4" either.
The application is using doweled tenons and in general dowel joints. I've
used brad point bits up to now but need to move to use of brace and bit. I
have only one bit that is an antique, but picked up a set of bits that
disappointed me in the variations in their dimensions.
I will seek out the ANSI standard, if it exists.
"dpb" <[email protected]> wrote in message
news:[email protected]...
>
> John Gonser wrote:
>> I found that several of the auger bits (Jennings pattern) that I recently
>> purchased are not accurately sized. Anybody know what the size tolerance
>> should be for the diameter at the spur and of the auger itself?
>
> No, I don't know but I do know there are ANSI and ISO standards for
> twist drills and I presume there would be for other varieties as well.
> I'd start looking in those directions if it is really that significant.
> Of course, what a Standard says is of no benefit if the manufacturer
> isn't following it... :)
>
> Just out of curiousity, what's the application that requires such
> precision and what kind of measurements are you getting?
>