Metric done wrong.

[whitmore]

I just got a bargain die, for a 1/4-32tpi application (oil fitting) that has been on my to-do list.

So, instead of a two-digit price after shipping, I paid small. Unfortunately, it's not a 1" circular die, it's 13/16" circular.
That's OK, I've got (one) die wrench that should work... Nope, doesn't fit. It's a metric thing.

Alas, measured outer diameter of the die is 0.775". Nominal diameter for this (13/16" :== 0.8125" ) is
ok for the clearance on my holder (0.818") and far exceeds the through diameter of the holder throat (0.774").
But a 0.775" die just will NOT clamp, or center, or even stay straight, in this holder.

So, maybe if I wrap some tape around it it'll fit the holder? Maybe? Well, no. It always cocks
sideways with any attempt on steel. With some care, I got a plastic rod to take a thread,
and it does fit my oil port (so I CAN plastic-plug against dirt intrusion).
After a close-fitting washer is fitted in the holder, the die at least is straight
(but not clamped securely).

Twenty millimeters is 0.7874", and apparently that's the intended die holder size.
Not available from most good industrial suppliers, but some clever soul has put the
right description on eBay, so... it'll be here in a month, two at most, from the Far East.
Checking the feedback, I find the following high praise: "ok quality".

The die seller didn't describe the OD. A photo is NOT enough data.
The holder was made with an open throat excessively over the through diameters to be expected.
The die wrench sellers in this country don't allow for metric sizes, only stock 13/16", 1", etc.
The buyer (me) didn't know what he was buying.

I'm sensing a non-abundance of common sense.

 

[kd4gij]

If you have a lathe and ,or mill make a holder.

 

[CluelessNewB]

Maybe some shim stock rather than tape?

 

[whitmore]

Maybe some shim stock rather than tape?

I used some stiff plastic tape, basically similar to shim stock. It was good enough for a test, but clumsy.

The die just falls through this holder unless a tight washer is used to close the throat, and the washer
is too thick to allow the clamp to bite... there's just too many things wrong, no combination of
fixes is completely workable. Fabricate a holder or buy-online (6-10 weeks shipping) are my best options.

When the other projects (motor , belt, and toolholder) are done, and the lathe is spinning, it'll be easy to
make a die holder or three. The mission for this die was building the (missing) oil cup for the lathe spindle.

 

[chips&more]

Just make a metal spacer ring with some holes so the set screws can go through it…Dave

 

[Norseman C.B.]

If you have a lathe and ,or mill make a holder.

Plus one on that, then if you need it down the road you have it.....