Hole size after heat treat? - Page 2
Close
Login to Your Account
Page 2 of 3 FirstFirst 123 LastLast
Results 21 to 40 of 60
  1. #21
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    6,115
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2930

    Default

    Quote Originally Posted by implmex View Post
    2) Make some in a range of sizes, pick the best one, make them all like that and PRAY, knowing you will likely have to pitch a few and lap a few.
    After a life of too much optimism, I am now a pessimist No matter what you do, the heat treater can blow your plan.

    Before I do anything iffy now I ask myself, "Do ya feel lucky, punk ?"

    It's a bit more trouble but your option #1 is dependable.

  2. #22
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    Quote Originally Posted by Terry Keeley View Post
    Press fitting a 0.200" pin in some S7 parts.

    Will the hole close or open during heat treat? During tempering specs says the material grows 0.1%. I've searched the forum and elsewhere and both answers are given.

    What say ye?
    what is the material and what is the heat treat required, .200 hole is small
    edit: the variance in heat treat will depend on the process used and will very with heat treaters, quenching medium used, heat treat procedure, don't let them blast the parts, it will open up the holes,

  3. #23
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    also it always better to finish precision holes after heat treat, hone it leave minimal stock

  4. #24
    Join Date
    Mar 2005
    Country
    UNITED STATES
    State/Province
    Indiana
    Posts
    5,372
    Post Thanks / Like
    Likes (Given)
    1687
    Likes (Received)
    1603

    Default

    I'm with the guys saying leave some stock if the fit is critical. I have seen the holes go both ways also.

  5. #25
    Join Date
    Jun 2002
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    2,893
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2570

    Default

    Hi again Emanuel:
    I agree 100%...if you go with option #2 and all the holes grow...Ye're Fooked!!.
    If they all shrink you have to lap or hone them all anyway, so you gained nothing from the risk you accepted.
    But if none of them move...you're a winner.

    How's this for another option:
    Heat treat all the bars then hard turn them and cross drill them AFTER hardening.
    There are circumstances where this could make the most sense, and if this were 17-4 PH at 45 RC instead of S-7 at 58 RC we wouldn't even need to have this conversation...it would be obvious and we'd all be on board.

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

  6. Likes eKretz, TeachMePlease liked this post
  7. #26
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    6,115
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2930

    Default

    Quote Originally Posted by implmex View Post
    How's this for another option:
    Heat treat all the bars then hard turn them and cross drill them AFTER hardening.
    Sounds like a weener

    But ya know what ? From the description of what he's trying to do, I'd still hone them. Honed holes are rounder, straighter, and hold size better than drilled or reamed or pretty much anything else. Honing is a really good process.

  8. #27
    Join Date
    Jun 2002
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    2,893
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2570

    Default

    Hi again Emanuel:
    You'll get no argument from me on that!!

    So Terry:
    Is it time for a Sunnen hone in a corner of your shop?
    If you get one I'll be jealous!

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

  9. #28
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    honing is only as straight as the hole all ready is, honing will true up the diameter, otherwise it will follow the hole.
    if it needs to be straight then it needs bored or jig ground, run a sample test and hone them and see if it's acceptable.

  10. #29
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    6,115
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2930

    Default

    Quote Originally Posted by 1953chevB View Post
    honing is only as straight as the hole all ready is, honing will true up the diameter, otherwise it will follow the hole.
    This is not true, unless you are talking about those phony-ass spring-loaded "brake hone" kind of things. A real hone straightens a hole out zippety-doo-dah.

  11. #30
    Join Date
    Jun 2002
    Country
    CANADA
    State/Province
    British Columbia
    Posts
    2,893
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2570

    Default

    Zippety-doo-dah???
    Is that a machining term?
    I'm unfamiliar with that one!

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

  12. #31
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,427
    Post Thanks / Like
    Likes (Given)
    394
    Likes (Received)
    528

    Default

    Quote Originally Posted by implmex View Post
    Hi again Emanuel:
    You'll get no argument from me on that!!

    So Terry:
    Is it time for a Sunnen hone in a corner of your shop?
    If you get one I'll be jealous!

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

    I looked at them a while back when I was re-chroming and finishing the tapered brass sleeves on my model engines but the little NSK Falcon grinder did a better job:





    I guess I could grind them but for only a couple it's hardly worth it, that's why I was hoping to hit the size close and just finish lap them.

    Should know later today how they come out...

  13. #32
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    Quote Originally Posted by EmanuelGoldstein View Post
    This is not true, unless you are talking about those phony-ass spring-loaded "brake hone" kind of things. A real hone straightens a hole out zippety-doo-dah.
    bull, have you honed

  14. #33
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    to true up a hole it has to be bored, jig ground or ID grind, depending on the type of part.
    edit: and I left out unconventional machining, Wire & electrode EDM, and others

  15. #34
    Join Date
    Jun 2008
    Location
    Bellingham, WA
    Posts
    4,261
    Post Thanks / Like
    Likes (Given)
    1032
    Likes (Received)
    2360

    Default

    An idea from 'left field."

    Make it differently. Based on appearance of the parts the OD of the cross piece need not be controlled to tenths.

    Might be interesting to make the cross pieces each a little over 1/2 the desired total cross-pin length separately with male and female tapers of about 1.5 degree included angle. The wall of the female taper should be about 10% of the diameter of the cross piece and undersized by a 5 tenths or so. Bored and turned tapers should be good enough so that grinding is not needed. Heat treat the parts. Then place them in the cross bore and press them together. Use Loctite as "suspenders" if desired. Pressing them together will result in swelling of the female pin diameter sufficient to make a tight fit in the cross hole and that taper will never release. I'd trust the taper (similar to a taper pin) over a simple press fit. Disclaimer: I've never made that exact part, but I am pretty sure this would work fine based on other similar experiences. A bit of experimentation to get the initial dimensions right would be needed. I think it would be an interesting way to make the part.

    Denis

  16. Likes Terry Keeley liked this post
  17. #35
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,427
    Post Thanks / Like
    Likes (Given)
    394
    Likes (Received)
    528

    Default

    Well I guess a dozen parts could end up all different but on the one I just made the hole actually opened up slightly, I'd guess a couple tenths.

    I bored the hole initially so a 0.200" - gauge pin was a "tight" fit. I mean you had to have it lined up exactly right and then it took a bit of pressure to get it in.

    Now it slides right in, not sloppy at all but an easy "slip" fit.

    Go figure.

  18. #36
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    6,115
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2930

    Default

    Quote Originally Posted by 1953chevB View Post
    bull, have you honed
    Enough to get it right, I guess. Maybe you should practice more.

  19. #37
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    Quote Originally Posted by EmanuelGoldstein View Post
    Enough to get it right, I guess. Maybe you should practice more.
    I can tell by your comments your full of it

  20. #38
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    6,115
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2930

    Default

    Quote Originally Posted by 1953chevB View Post
    I can tell by your comments your full of it
    Then maybe when you get a moment you can explain to the general public how a stone that is 2" long with a metal backing is going to follow a hole that is 1" long. I'll be interested to learn how that works myself.

    Quote Originally Posted by implmex
    Zippety-doo-dah???
    Is that a machining term?
    I'm unfamiliar with that one!
    Kids these days ! I'm not sure the world is ready for this tho ...


  21. #39
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    California
    Posts
    488
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    93

    Default

    I guess we are discussing apples and oranges. I discussing about long deep holes with 5x depth of the diameter. Most are bored then honed to true up.
    The diameters with large diameters have to be w/I true position before honing.
    If you look at the amount of stock removal
    It is very little. If the bores are out of position, with very little stock it will not correct true position.
    That's why it has to be bore w/I true position. Otherwise more stock has to be left ground.

  22. #40
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    6,115
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2930

    Default

    Quote Originally Posted by 1953chevB View Post
    I guess we are discussing apples and oranges.
    I'm discussing the topic of the thread, no idea what you are doing.

    But Terry, in your place, I'd make them slightly under, get a valve guide hone from Sunnen, and take a half thou or a little more out of all of them for finish size. You can run that with a hand drill. It's fast and your holes will be rounder and straighter and the pins will fit better. Grab a Venolia piston with a sliding fit pin and see what I'm talking about.

  23. Likes Terry Keeley 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
  •