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Looking for 1/2x13 Geometric Die Head inserts


Apr 9, 2009
I have bud that is looking for a set of 1/2 x 13 inserts for a 3/4" Geometric Die Head . Says the brand is Geometric DIe Head co .
He should look for 1/2-13 chasers for a 3/4D die head. Unless he has a different model, but chasers for the 3/4D are very easy to find. The trick is to search for chasers, not inserts. Companies other than Geometric make chasers to fit the 3/4D. The usual large supply houses have new sets.

Here is a set he can bid on.

Thanks , MY knowledge on these die heads started today when I had on win my hands . WHats teh difference between inserts & chasers , or are there no such things as inserts ?
Inserts exist. Chasers are a different item.

Long ago, threads were cut in lathes with hand-held tools called chasers. Think chisel with thread-shaped end and a wood handle. They came in inside and outside shapes. It takes a little practice to use them, but they can produce a good thread.

Hand chasers cropped small.jpg

Later, when die heads were invented, it was natural to call the cutting tools chasers.

Here is a Geometric 3/4DD die head that takes 3/4D chasers.

3-4DDGeo 1 1.JPG

Wow , thanks very much Larry ! I learn so much from you folks here . I will pass the info on to my bud . We didn't even cover that stuff in shop in the early 70's
thanks again
@animal12, you will find that there are different styles and pitch angles (see ebay ad link posted above) for different types of materials i.e. stainless steel, mild steel, etc. Having the correct chaser for the material you are using does make a difference, especially when working with stainless steel.
Will look to see if I have a spare set.
Best of luck!
The first Geometric die head I bought (used for $100) had a patent date, as I recall, of 1900. It was one of their first 9/16D models, but still worked fine. So yes, before CNC. I made a thousand or more parts (small one man shop) with my die heads on hand turret lathes back in the 1980's.

I could tell by checking the die head out that it was a very nicely made tool . I bet it made a lot of folks's jobs faster & easier .