[SEL] Tap & Die Set Help Needed--OT

Dave Rotigel rotigel at alltel.net
Wed Mar 15 19:51:14 PST 2006


Hi John, ALL the taps and ALL the dies in the set that I bought (except for 
the 1/2 X 12) are 1/32 OVERSIZED!
         Dave

At 07:43 PM 3/15/2006, you wrote:
>A little late chiming in but here are my thoughts.
>Are both oversize or is one over and the other under. My thought is 
>someone was trying to make patterns/castings already threaded and possibly 
>hoping to just clean the parts up with an on size tool after casting. I 
>also thought if the tap is undersize and the die is oversize then maybe 
>they were used for roughing with standard taps and dies used for finishing?
>
>For what it is worth, all taps are oversize, at least real ones not made 
>in China. They are designated with an H limit.  An H3 tap is .0015 
>oversize, an H6 is .003 oversize--for every number the H value increases, 
>the tap increases .0005 in size.
>
>Can't say I ever heard of an oversize die other than adjustable dies.
>
>Oversized taps, as was stated earlier, are used often where shrinkage from 
>heat treat, hard-coat anodize, or nickel plating comes into play. But we 
>are normally talking just a few thousandths--not 31.
>
>Someone also mentioned 12 pitch threads and yes they are still widely used 
>on hydraulic cylinders.
>
>John Hall
>
>
>
>
>----- Original Message ----- From: "Dave Rotigel" <rotigel at alltel.net>
>To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
>Sent: Sunday, March 12, 2006 1:13 PM
>Subject: [SEL] Tap & Die Set Help Needed--OT
>
>
>>Hi All,
>>While at the Zolfo Show a week or so ago I picked up a nice old tap and 
>>die set made by Wiley & Russell (Greenfield, Mass.) (It's got to be 
>>rather old because the 1/2 " die indicated 12 threads per inch!) The set 
>>goes from 1/4" to 3/4" and each die (while removable) has it's own 
>>handle! The set is in a nice old wooden box measuring  37 1/4" X 10 3/4" X 3".
>>Now my question. Each die has 1/32 stamped (or perhaps engraved) into it. 
>>What does this 1/32 stand for/mean? Any help on this will be appreciated!
>>Dave
>>
>
>
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