# Bridgeport J Head Mill Nut/Wrench sizes...?



## EmilioG (Feb 11, 2018)

I've been away from any Bridgeport mills lately and would like to know the wrench/nut sizes for the mills worm gear adjusters and knuckle bolts.
I may need to tram the mill and want to make sure I bring the correct wrenches for these bolts/nuts. There are four in front and two worm gear nuts yes?

Also, is a 14" arc wide enough to tram the BP mill? 7" for each axis?


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## Hukshawn (Feb 11, 2018)

My clone J-head are all 3/4". I say that with a grain of salt, but every other aspect of my clone has been identical to a Bridgeport.
And I tram my head with about a 10" swing. So, 14" should be plenty. So much so, that you'll run off the ends of the Y axis unless you use some straight edges.


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## EmilioG (Feb 11, 2018)

Thanks.  When you say 3/4", is that the bolt size or the wrench size?  I.e. a 3/4" hex bolt requires a 1 1/8"- 1 1/4" wrench.


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## Hukshawn (Feb 11, 2018)

That's the wrench size.


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## Dredb (Feb 11, 2018)

3/4 sounds right to me, one wrench fits all the head clamping and adjusting nuts.


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## Hukshawn (Feb 11, 2018)

3/4" is literally the only wrench at my mill. The draw bar too.


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## EmilioG (Feb 11, 2018)

Awesome. Thanks. I have several 3/4” wrenches, open, box, 6 and 12 points, long, and short.


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## Ulma Doctor (Feb 12, 2018)

it's funny, the Kurt vise i have is 3/4" hex on the handle, and so is all the moving hardware on the BP.
i have used the vise handle to loosen the nuts and drawbar too!


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## Tony Wells (Feb 12, 2018)

3/4" hex heads are standard, pretty much. Until you address the hold down system. Those typically are 7/8". I have, hidden somewhere, a welded 3/4 X 7/8" shop made combination box wrench. Haven't seen it in years though.


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## EmilioG (Feb 12, 2018)

They make 3/4 x 7/8" wrenches.


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## Tony Wells (Feb 12, 2018)

Oh, I know but I wanted box end. They probably are out there, and I probably have at least one, but back when I made mine it was just the easiest way to get what I wanted.


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## Dabbler (Mar 1, 2018)

Sears sells a 3/4" X 7/8" box end wrench.  I had to order it recently from Sears USA and had it sent to a friend.  (they wouldn't ship to the great White North)

Everything except the Ram Lock bolts are serviced with the above wrench.  I can't remember the size of the ram lock bolts, cause I have an adjustible wrench hanging there for msc bolts...


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## Tony Wells (Mar 1, 2018)

Yes, they do. I have one (a couple, actually). It's the shop made I seemed to have lost.


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