chrisg
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| posted on 29/11/07 at 09:56 PM |
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Bar size?
This is one of those where I think the answer is obvious, but I'm not certain.
If you need to cut an M12 thread onto a steel bar with a die, do you need bar that is EXACTLY 12mm or slightly bigger or smaller?
Thanks in Advance
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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oadamo
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| posted on 29/11/07 at 10:04 PM |
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measure a m12 bolt and add 1mm to the outer dia.
adam
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nick205
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| posted on 29/11/07 at 10:04 PM |
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Ø12mm bar would be the correct start point I believe. I can check me Zeus book if need be
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oadamo
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| posted on 29/11/07 at 10:05 PM |
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http://www.sealey-tools.co.uk/instructions/AK3002.PDF
adam
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oadamo
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| posted on 29/11/07 at 10:06 PM |
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quote:
Originally posted by nick205
Ø12mm bar would be the correct start point I believe. I can check me Zeus book if need be
just looked cant find it lol
adam
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Andy W
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| posted on 29/11/07 at 10:15 PM |
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you need 12mm o/d
Andy
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chrisg
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| posted on 29/11/07 at 10:18 PM |
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Thanks for the replies chaps, it says on that link that the bar should be 0.005" to 0.0010 undersize. What's that in metric? (and the
21st century)
Cheers
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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Mansfield
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| posted on 29/11/07 at 10:18 PM |
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12.0 to 11.9 would be perfect
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Mansfield
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| posted on 29/11/07 at 10:19 PM |
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That is 11.975-11.875 I think. 0.001" = 0.0254mm
[Edited on 29/11/07 by Mansfield]
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chrisg
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| posted on 29/11/07 at 10:24 PM |
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I've got 12mm exactly, so I should be ok?
Cheers
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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Mansfield
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| posted on 29/11/07 at 10:29 PM |
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You will be fine, use plenty oil and keep it square.
If it it a split die you could open it right up for a first pass and close it to finish size for a second pass if you fancied.
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dhutch
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| posted on 29/11/07 at 10:51 PM |
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The nominal dimention is indeed the OD of the male thread before its cut.
- With the nomial dimention minus the pitch being a good aproxamation of the ID of the female.
However, there are tables with all of this in. Zeus, etc.
Daniel
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MikeRJ
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| posted on 1/12/07 at 01:33 AM |
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quote:
Originally posted by Mansfield
If it it a split die you could open it right up for a first pass and close it to finish size for a second pass if you fancied.
Unless it's make from Chinese "high carbon steel" in which case you end up with a special two piece die
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iank
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| posted on 1/12/07 at 11:35 AM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by Mansfield
If it it a split die you could open it right up for a first pass and close it to finish size for a second pass if you fancied.
Unless it's make from Chinese "high carbon steel" in which case you end up with a special two piece die
Coffee on screen moment
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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blueshift
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| posted on 1/12/07 at 12:06 PM |
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I bought a couple of cheap tap and die bits, utter utter crap. You know when you have to file off the burrs on your tap, that something is not right.
Plus the thread it cuts could be described as a slightly rippled slip fit for the bolt.
I have a bookmark for this place: http://www.tapdie.com/ which may have come from another post on here, never used them, but intend to when
I need taps + dies again. Looks like the real deal at reasonable prices.
I know this wasn't a "where do I get tools" thread but I came over all helpful 
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wicket
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| posted on 1/12/07 at 10:07 PM |
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Lots of useful info on here, including metric threads.
http://www.engineersedge.com/Design_Data.shtml
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