Favorite steel for milling? - Page 3
Close
Login to Your Account
Page 3 of 3 FirstFirst 123
Results 41 to 53 of 53
  1. #41
    Join Date
    Feb 2013
    Country
    UNITED STATES
    State/Province
    Idaho
    Posts
    653
    Post Thanks / Like
    Likes (Given)
    132
    Likes (Received)
    708

    Default

    No question 12L14 is one of the easiest steels to machine... one of my vendors calls it butter steel Then again he refers to his wife as Butter Face... everything about her is hot but her face.

    For some reason I have been machining more and more 1144(Stressproof) when I need a more strength. I get very good surface finish and reasonable feeds and speeds. On the stainless front, I have been using lots of 416, I like that as well.

  2. Likes eaglemike liked this post
  3. #42
    Join Date
    Nov 2013
    Country
    UNITED STATES
    State/Province
    Utah
    Posts
    4,372
    Post Thanks / Like
    Likes (Given)
    1170
    Likes (Received)
    2397

    Default

    Quote Originally Posted by TheTalman1 View Post
    Rob I am well aware of the math on the subject. I am also aware that the math doesn't always follow real world finish. Just as your surface finish can come out far worse than the numbers would suggest it can go better as well

    I checked with 3 different profilometers, shop is AS9100 Cert. everything calibrated on the regular. I checked it against our reference cards anyway and so did QC. At .0015ipr finish was actually worse .0035-.004ipr was the sweet spot as long as the surface footage was up high enough. It was very counter intuitive.

    Are you really suggesting that I was stating "Shiny" as a measure of surface finish? After I gave you the measured numbers? Your response is our equipment is off about 70 points? I guess every Aerospace part with a surface finish callout that left the building was wrong then. Might as well close up shop because rob can't believe that I got a decent finish out of 12L14.

    Sometimes shit just works out. Believe what you will, Not My Problem.
    Damn, I wish everyone had that much respect for me.

    It was probably magic or luck maybe, that you beat the mechanical physics and know machining truths, to get good parts.

    Don't be so sensitive.

    R

  4. #43
    Join Date
    Nov 2004
    Location
    WI
    Posts
    4,679
    Post Thanks / Like
    Likes (Given)
    440
    Likes (Received)
    1067

    Default

    Quote Originally Posted by mhajicek View Post
    Depends on the shape and orientation of the insert too, not just the radius. Could be one of the insert's flats was cutting off the crests.
    Isn't that referred to as a Wiper geometry?

  5. #44
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Wyoming
    Posts
    3,208
    Post Thanks / Like
    Likes (Given)
    7725
    Likes (Received)
    5149

    Default

    I'll vote for 12L14. You can get a pretty nice shine on it, almost equaling the appearance of a harder material like 4140, using large-nose-radius cermet inserts running as fast as your spindle will turn. It will rust easily but zinc plates just fine, especially with gold chromate afterward. Likes green cad too.

    My vote for second place would be Stressproof. Yeah, it only comes in rounds and hex but if you keep lots of it around and occasionally need to make a small high-strength T-nut, mill clamp or something similar it can be well worth face-milling a hunk of drop into a square for some ready stock. Face-mill Stressproof with wiper inserts and you can get as close to a machined mirror as it's possible to get.

  6. Likes eaglemike liked this post
  7. #45
    Join Date
    Nov 2004
    Location
    WI
    Posts
    4,679
    Post Thanks / Like
    Likes (Given)
    440
    Likes (Received)
    1067

    Default

    None of these parts are turned. All milled.
    Probably with a 2mm end mill, due to feature sizes, and features inside of pockets.
    Most likely on the fourth axis to reduce number of operations.

    Around 60,000 parts per year.

    C12L14 is on order... So, the adventure begins.

    Thanks again to everyone.

  8. Likes eaglemike, Oldwrench liked this post
  9. #46
    Join Date
    Jan 2007
    Location
    Flushing/Flint, Michigan
    Posts
    7,593
    Post Thanks / Like
    Likes (Given)
    378
    Likes (Received)
    6342

    Default

    Quote Originally Posted by TheTalman1 View Post
    Rob I am well aware of the math on the subject. I am also aware that the math doesn't always follow real world finish. ....
    Sometimes shit just works out.
    Actually it should follow the math, if not perhaps you have the math wrong and need to question why or what is going on.
    If you just accept it you are not understanding and going with shit ass luck. At this point Murphy is waiting in the wings to make your life miserable.

    There is more to surface finish than corner radius and you maybe don't need a "wiper".
    I can do do 4-8 with a .006 radius and much higher feeds per tooth.
    This on a milling cutter and many millions of parts shipped.
    Logic and math would say no.
    Want lathe, how about crankshaft thrust walls and the same millions in the field?
    The trick is to cut off the back end of the cusp. Think almost zero laydown out back. Sort of like a wiper which is normally crowned.
    All tools cut behind the high tip point. Something often missed. Too much and you get chatter as the heel geometry goes to shit fast in most cases.
    You would have to be way the puck turned to do so with a "V".
    Big rad wipers do this but sometimes the tool pressure gets in the way and/or you can't finish to a lathe bottom corner.
    Bob

  10. Likes Oldwrench liked this post
  11. #47
    Join Date
    Oct 2010
    Location
    Dewees Texas
    Posts
    2,307
    Post Thanks / Like
    Likes (Given)
    26
    Likes (Received)
    621

    Default

    Quote Originally Posted by 3t3d View Post
    None of these parts are turned. All milled.
    Probably with a 2mm end mill, due to feature sizes, and features inside of pockets.
    Most likely on the fourth axis to reduce number of operations.

    Around 60,000 parts per year.

    C12L14 is on order... So, the adventure begins.

    Thanks again to everyone.
    In the old days you could get 12L14 with different additives such as selenium or tellurium. There was one other additive in the old Jorgensen catalog. I used to get the one with selenium as selenium in stainless made it more malleable and less apt to crack in cold working, figured it would do the same in 12L14 when used on swaged cable fittings.

    With 60,000 pcs a year a variation might improve your milling or plating. You might have enough clout with that kind of production to get the best variety for your needs.

  12. #48
    Join Date
    Nov 2004
    Location
    WI
    Posts
    4,679
    Post Thanks / Like
    Likes (Given)
    440
    Likes (Received)
    1067

    Default

    These are pretty small parts, so not a Lot of leverage on volume. Well maybe. I Bet they will know my name at the steel sales yard.

    More importantly, getting approval for any variation in material is a non starter.
    This has to conform to REACH, ROHS, and Dodd-Frank Conflict minerals certification, etc....

    Switching to a common alloy, OK... Anything not already in the "approved list" and No go.

  13. #49
    Join Date
    Jun 2018
    Location
    Posts
    62
    Post Thanks / Like
    Likes (Given)
    130
    Likes (Received)
    21

    Default

    Quote Originally Posted by CarbideBob View Post
    Actually it should follow the math, if not perhaps you have the math wrong and need to question why or what is going on.
    If you just accept it you are not understanding and going with shit ass luck. At this point Murphy is waiting in the wings to make your life miserable.

    There is more to surface finish than corner radius and you maybe don't need a "wiper".
    I can do do 4-8 with a .006 radius and much higher feeds per tooth.
    This on a milling cutter and many millions of parts shipped.
    Logic and math would say no.
    Want lathe, how about crankshaft thrust walls and the same millions in the field?
    The trick is to cut off the back end of the cusp. Think almost zero laydown out back. Sort of like a wiper which is normally crowned.
    All tools cut behind the high tip point. Something often missed. Too much and you get chatter as the heel geometry goes to shit fast in most cases.
    You would have to be way the puck turned to do so with a "V".
    Big rad wipers do this but sometimes the tool pressure gets in the way and/or you can't finish to a lathe bottom corner.
    Bob
    "Should" but then things like coolant, surface footage, workholding, and insert geometries come into play with the math suggesting a theoretical best finish. And in a shop environment where I am running several machines at once with short quantities there's only so much time I can put around and try to figure out the whys and why not's per job. All I can do is make a note of what the material was and the feeds and speeds where and what the results were. These parts were a prototype run so short quantities of 8 a piece with 5 or 6 sets sharing similar dimensions, and as always not a lot of time to do them in I got lucky true but it also repeated again with a slight degradation in finish on another prototype run in the same family in 1018 with a few adjustments on the same machine with the same kind of insert.

    I lay things down like that sometimes on manual lathes but never on my CNC's, the kennametal VNGP 3305 was held in a "Standard" orientation ie ~5-6 degrees back from 90 and 50 degrees up off the diameter. It is of course possible that with a .008r insert it flattened the cutting edge slightly creating its own small "wiper".

  14. #50
    Join Date
    Jun 2018
    Location
    Posts
    62
    Post Thanks / Like
    Likes (Given)
    130
    Likes (Received)
    21

    Default

    Quote Originally Posted by litlerob1 View Post

    It was probably magic or luck maybe, that you beat the mechanical physics and know machining truths, to get good parts.

    R
    Black magic actually, step one of every set-up is to bathe the controller in lambs blood, and draw a pentagram on the turret. shit gets really weird after you cut 666 parts.

  15. Likes mhajicek liked this post
  16. #51
    Join Date
    Oct 2010
    Location
    Dewees Texas
    Posts
    2,307
    Post Thanks / Like
    Likes (Given)
    26
    Likes (Received)
    621

    Default

    Quote Originally Posted by 3t3d View Post
    These are pretty small parts, so not a Lot of leverage on volume. Well maybe. I Bet they will know my name at the steel sales yard.

    More importantly, getting approval for any variation in material is a non starter.
    This has to conform to REACH, ROHS, and Dodd-Frank Conflict minerals certification, etc....

    Switching to a common alloy, OK... Anything not already in the "approved list" and No go.
    Those were just variations of 12L14, I think substitutes for the sulfur to modify machining characteristics slightly.
    I went through the Dodd Frank stuff several years with one customer over the use of carbide inserts. Turns out there is an out for inserts used in production that you do not have to fill out the rest of the intrusive form. See post 18 in this thread:
    EU certifications

  17. #52
    Join Date
    May 2017
    Country
    UNITED STATES
    State/Province
    Minnesota
    Posts
    930
    Post Thanks / Like
    Likes (Given)
    1098
    Likes (Received)
    573

    Default

    Quote Originally Posted by TheTalman1 View Post
    Black magic actually, step one of every set-up is to bathe the controller in lambs blood, and draw a pentagram on the turret. shit gets really weird after you cut 666 parts.
    Can you cut a pentagram with polygonal turning?

  18. Likes TheTalman1 liked this post
  19. #53
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Wyoming
    Posts
    3,208
    Post Thanks / Like
    Likes (Given)
    7725
    Likes (Received)
    5149

    Default

    Quote Originally Posted by FredC View Post
    In the old days you could get 12L14 with different additives such as selenium or tellurium
    12L14Te is still available from EMJ (Jorgensen). Machinability given as 250% of 1212 as opposed to 193% for standard 12L14. I'd think it would be worth it in time and tool life for that many parts.

    The analogous comparison in aluminum is that of 6061 to 2011. Although a high-speed CNC machine doesn't care all that much, back when we made parts on manual machines that 20-30% machinability improvement was miraculous.

  20. Likes eaglemike liked this post

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •