Subject: Re: Worping Steel

From: [email-masked] (Gary Rosenkranz)
Date: Mon, 19 Jul 93 23:44:00 -0500

Tony,
The molds that are made by my company are mostly prototype molds that
are used for small production. They are made out of alum. and I have
been experimenting with steel. The company I purchased the steel from is
exchanging the steel for a better grade that is not cold formed but (
hot formed ) they say that it will not have the same problem. Off hand I
don't know what the grade is but they did tell me and i have it written
at work.
   My prior machinest did make some molds out of steel and did
experience some problems. He did not make a big deel about it and made
corrections by milling and surface grinding. I was not aware what the
exact problem was until the job was finished. My new Machinest has 25
years experience. When I got the 1018 steel delivered he started using
it and he let me know right away that there was problems with the stock.
I am getting more involved in the machining jobs and the machinest is
teaching me much.

                   Gary

---

From: [email-masked] (Joe Landau)
Date: Wed, 21 Jul 1993 05:26:20 GMT

Gary writes:
 
>I just purchased about 500 pounds of steel ( 1018 ) in various sizes
>from 3/8 square to 1 inch X 4 inch. When we mill the surface of the the
>steel, it machines fine but. When we take the stock out of the vise it
>immediatly bows ( worps)  this happens even when we only take 30
>thousands off the surface. The same situation happens when we use a fly
>cutter and a milling cutter. The larger the cut the more worpage.
>My question is: Is this normal with 1018 steel? Is there a better steel
>that will not worp when machining? I paid about $ 1.00 per pound for
>the 1018 steel. what is the cost per pound for other grades of steel
>that will suit my purpose.( worp free or slight worpage) The steel is
>used for making bases for injection molds and machining cavities for
>molds etc..
>Is there a good supplier of steel in the east? NY area? NJ?
>

I have read (but do not know firsthand) that crs is stressed by the forming
process, and when you machine it the stresses are unevenly relieved, so the
steel warps.  The cure is said to be annealing before machining.  

If you try this, let us know if it works.