Undersize Rod for Die Stock Threading

Correct, although I question the use of 1/4" material for 6MM threads. It's woefully oversized.

Harold

Harold sez:

"Correct, although I question the use of 1/4" material for 6MM threads. It's woefully oversized."

Harold,

Why'nt you just tell him the quick and dirty way to size taps drills for metric is: Drill diameter = Metric size - pitch in mm.

Bob Swinney

Oooppps ! To size rods for external metric threading: Nominal Diameter - (pitch X .866)

Bob Swinney

Oooopps! Wrong again - just wanted to see if you were awake. The rod size for metric threading is: Nominal diameter - (.125 X Cos 30 degrees) X pitch in mm.

Bob (shamefully bowing head) Swinney

Chuckle!

message

Of course you question it. I didn't make it clear. I didn't mention I filed the 1/4 inch rod to 0.234 inches minus a few mils. It threaded OK then, but I was looked for a rod that could be threaded with nearly no preparation.

The point I was trying to make was that M6 is *smaller* than 1/4 inch so turing or filing is mandatory. M8 is *bigger* than 5/16, so I tried it and the threads were beautiful. Most of them were sharp-V on the eyball inspector gage. :)

Let's see, the next size up is 3/8 inch, and M10 is 0.390. It's bigger than the inch size. Might work.

So, 1/4 inch rod is too big to thread M6. 5/16 in aluminum rod threds to M8 OK. and 3/8 inch rod might thread M10.

That summary is what I wanted to establish. Now to stock up on 5/16 inch aluminum rod through Amazon while my Prime subscription is still active. Small parts, $2.56 per 6 foot length, no shipping because of the Prime trial. Whee!

Doug

See what your local welding supplier stocks or will order for TIG rod. The largest I've found is 1/4" but they had a good variety of smaller sizes like 3/16" and 5/32" which can be threaded #10 and #8, or 5mm and 4mm.

jsw