CNC Lathe Single Point ID Threading Help For First Timer

[Guest]

I often program a slight taper to I.D. threads to counteract any flexing of the thread tool.

6" long 4140 Hex parts, I bet material is pricey. Seems like the price of 4140 hex has quadrupled over the last 10 years and then some.

Hex? Oh yeah, that is not a cheap bit of material.
It seems most materials have gone up in price; though, the price of scrap [anything] is lower than I have seen in the last 10 years.

I have made some 4" long bolts out of 4140 for the same customer for the last 12 years. Back on the first batch I had a local source I got the hex from for a little over $1 a pound. When it hit $4 a pound 6 years ago I just started making them out of round and milling the hex head.

 

[doug925]

... I just started making them out of round and milling the hex head.

Most of our orders are 50-500 pcs, so milling a hex on a bar (in the lathe) is usually the way to go, cost wise.
(unless the parts are long, or need a hex where I cannot get to in the opp)

 

[Guest]

Most of our orders are 50-500 pcs, so milling a hex on a bar (in the lathe) is usually the way to go, cost wise.
(unless the parts are long, or need a hex where I cannot get to in the opp)

I have some 2.250" long parts with the hex running the whole length. Fortunately they are out of 12L14 and hex in that type still isn't much more than round. I wonder why with 4140 the hex is so much more than the round price per pound?

 

[doug925]

I have some 2.250" long parts with the hex running the whole length. Fortunately they are out of 12L14 and hex in that type still isn't much more than round. I wonder why with 4140 the hex is so much more than the round price per pound?

I do love to machine me some 12L14 or some 11L17.
Maybe the 4140 hex is more expensive to make, given the mechanical properties, or, it could be (and probably is) because they can make more $$$$.
Look at the Pharma industry on Epi pens.... $100 in '09, and $600 today.