Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Hunting
Long Range Hunting & Shooting
300 Below cryo process on my 338 lapua
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Nimrod" data-source="post: 591785" data-attributes="member: 6327"><p>I am a machinist by trade and have had to deal with stress related issues from time to time. From my observations stress is not actually caused by the machining processes but is induced in the manufacture of the material. The machining process simply brings it to the surface, for best results the material should be stress relieved before any machining process takes place. The stress relief process is usually done after the initial heat treating if there is any involved. It's hard to imagine just looking at a block of metal laying on a bench, how much stress can actually be involved but it can be significant. A particular instance I remember concerned a fair sized piece of titanium, I was doing prep work on it that consisted of facing both sides and putting bolt holes and counterbores down the sides. The material was about 7 or 8 feet long and around 24 inches wide by 2 1/2 inches thick. There was a thickness call out of 2.250 +/- .010 after machining, the material was as received from the vendor. The normal procedure was to face about .125 from the first side and and then flip the material over, face the second side to finish dimensions and drill/counterbore the holes. This particular piece of material was bowed in both directions, in the thickness plane it would have required nearly an inch of material removal to make it flat and in the long dimension the 3/4" bolt hole nearest one end would have been completely off the part. We sent it back to the mill to be stress relieved and it came back flat and straight to within a few thousandths of an inch. In this case I think the block was sawed from the end of a large plate and warped after sawing. Normally I see the most movement near the ends of a piece of material. The machining process will cause the stress to manifest itself, especially if material is not removed equally from all sides. In my opinion for cryo treatment to have any significant effect , it would need to be done prior to any metal removal. I used to work in a shop that bought a cryo tank to treat cutting tool inserts in an attempt to get more life out of them, it didn't work.</p><p></p><p>Sorry for the long post! </p><p></p><p>Hey Kevin, you guys don't need a machinist do you <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /> ?</p><p></p><p>Bob</p></blockquote><p></p>
[QUOTE="Nimrod, post: 591785, member: 6327"] I am a machinist by trade and have had to deal with stress related issues from time to time. From my observations stress is not actually caused by the machining processes but is induced in the manufacture of the material. The machining process simply brings it to the surface, for best results the material should be stress relieved before any machining process takes place. The stress relief process is usually done after the initial heat treating if there is any involved. It's hard to imagine just looking at a block of metal laying on a bench, how much stress can actually be involved but it can be significant. A particular instance I remember concerned a fair sized piece of titanium, I was doing prep work on it that consisted of facing both sides and putting bolt holes and counterbores down the sides. The material was about 7 or 8 feet long and around 24 inches wide by 2 1/2 inches thick. There was a thickness call out of 2.250 +/- .010 after machining, the material was as received from the vendor. The normal procedure was to face about .125 from the first side and and then flip the material over, face the second side to finish dimensions and drill/counterbore the holes. This particular piece of material was bowed in both directions, in the thickness plane it would have required nearly an inch of material removal to make it flat and in the long dimension the 3/4" bolt hole nearest one end would have been completely off the part. We sent it back to the mill to be stress relieved and it came back flat and straight to within a few thousandths of an inch. In this case I think the block was sawed from the end of a large plate and warped after sawing. Normally I see the most movement near the ends of a piece of material. The machining process will cause the stress to manifest itself, especially if material is not removed equally from all sides. In my opinion for cryo treatment to have any significant effect , it would need to be done prior to any metal removal. I used to work in a shop that bought a cryo tank to treat cutting tool inserts in an attempt to get more life out of them, it didn't work. Sorry for the long post! Hey Kevin, you guys don't need a machinist do you :) ? Bob [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Hunting
Long Range Hunting & Shooting
300 Below cryo process on my 338 lapua
Top