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How to chuck a bolt head

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Philip Hardy22/09/2022 22:19:41
21 forum posts
2 photos

Whilst it may sound a straightforward question, I need to turn down 40cm off the end of a high tensile bolt for a project in y Myford ML7. Does anyone have a ny tips on how to set up the hex bolt in the jaws so that I can machine the end of the bolt

Grindstone Cowboy22/09/2022 22:23:55
1160 forum posts
73 photos

I always put a couple of nuts on the bolt - same size as the head, obviously, so there's no tendency for it to tip. They don't have to be tightened up, just get the flats aligned. Of course, this depend whether the finished length you are aiming for will allow for this.

Rob

Clive Foster22/09/2022 22:37:46
3630 forum posts
128 photos

Normal good practice is to use a sleeve on the bolt large enough to give clearance to the head and, hopefully, long enough for the chuck jaws to get a decently parallel grip.

Easier with fully threaded machine screws where an internally threaded sleeve can go right up to the head but a partially threaded, partial clearance drilled one works as well on a proper bolt with a pain portion of shank below the head.

Long joining nuts work well enough at this too should you have some. (I keep a small stock of the sizes Screwfix supply 'cos they are handy for oddball stuff and fixtures.). Or just lock a few nuts tigether. May take a bit of a heave to get the flats lined up after tightening but most are surprisingly good.

If the bolt is long enough or your chuck jaws shallow enough just grab the shank and be done with it.

I've been known to just grab the thread and be done with it when "get-er-done" trumps Inspector Meticulous.

Clive

Edited By Clive Foster on 22/09/2022 23:03:03

Nigel Graham 222/09/2022 22:43:16
3293 forum posts
112 photos

I've often used stacked nuts as Clive suggests, but sometimes you can align them without undue force by judicious waggling around.

If the bolts is long and you need turn an appreciable length of it, it's worth holding it as close in possible to centre the end, then supporting that from the tailstock when its withdrawn to the working distance. (Assuming a centre-drill hole won't affect the bolt's intended purpose.)

John Hinkley22/09/2022 23:03:05
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1545 forum posts
484 photos

40cm! That's a lot to take off a high tensile bolt. If I had one, I think I would remove the majority of it with an angle grinder and then clean up the end in the normal way.

John

peak422/09/2022 23:38:58
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2207 forum posts
210 photos

It would help if you gave us the before and after sizes, both length and diameter.
Also, do you really mean a bolt, a screw or an Allen headed cap-screw etc.

Bill

Peter Cook 623/09/2022 00:03:22
462 forum posts
113 photos

If you are simply shortening the bolt by 40mm, I would saw off most of it, and clean up the end to length on the belt sander.

The proper way of course is to use a lantern chuck.

Edited By Peter Cook 6 on 23/09/2022 00:05:55

Michael Gilligan23/09/2022 00:29:20
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23121 forum posts
1360 photos
Posted by Peter Cook 6 on 23/09/2022 00:03:22:

If you are simply shortening the bolt by 40mm, I would saw off most of it, and clean up the end to length on the belt sander.

.

I am just wondering where exactly the ‘typo’ is …

Philip actually wrote: I need to turn down 40cm off the end of a high tensile bolt …

so did he mean: I need to turn down 40cm of the end of a high tensile bolt …

Dunno !

MichaelG.

JasonB23/09/2022 07:42:03
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25215 forum posts
3105 photos
1 articles

If it's a big bolt then just hold by the hex head in the 3-jaw and use a fixed steady at the other end set far enough in to allow you to work on the hopefully 40mm .

Roderick Jenkins23/09/2022 09:00:51
avatar
2376 forum posts
800 photos

Hold the threaded end in the drill chuck in the tailstock, introduce the head into the 3 jaw chuck, tighten this, loosen the drill chuck and slide the tail stock out of the way.

Eric Tomlinson23/09/2022 09:27:47
5 forum posts

Hold the threaded end in the 3 Jaw and part off the desired length.

Philip Hardy23/09/2022 09:28:10
21 forum posts
2 photos

Thanks guys, great ideas. Just to confirm Im looking to turn down a 40cm length of the bolt's thread as I'm making a puller that the end needs to fit into a shaft hole.

Circlip23/09/2022 09:33:44
1723 forum posts

Good ole dressmakers sizes again, 40cm =400mm= 15 3/4"

Regards Ian.

Philip Hardy23/09/2022 09:35:59
21 forum posts
2 photos

Should read 15cm

DMB23/09/2022 09:42:00
1585 forum posts
1 photos

I would go with MichaelG s suggestion, take off bulk with the angle grinder then clean up on coarse bench grinder wheel and finish, if needed on belt sander. I would add that start off measuring, black marker pen, hold with pliers or molegrips, if large diameter and introduce it to the angle grinder. Anything over say 1/4" / 6mm diameter.

As Peter Cook6 said, anything special, use a lantern chuck.

I have just one slotted cheesehead 5/16" BSF X 3/8" long screw to make. This is how I plan to do it. Chuck round bar and turn down to overall thread diameter less 2 thou and use t/s dieholder. Part off. Drill remaining bar 1/2" deep and tap it. Screw in embryo screw fairly tight, part off bar about 5/8" from the end. Set up on a thin parallel in mill vice with head projecting from the side. Slitting saw in drill chuck, set up on Centreline of screw and to slot depth. Can probably do it in less time than it's taken me to type this. Others will probably say why not go out to nut and bolt store but I want to do this myself. If I had a lot to do, I would use a slightly different method, if specials but a common size, I would buy in. I also need 2 X 2BA slotted cheeseheads for another project, make same way.

Nigel Graham 223/09/2022 09:46:49
3293 forum posts
112 photos

Ah - thank you Philip. That extra information helps!

Merely holding it by the head alone is NOT a good idea especially when as seems, you need a lot of bolt protruding from the head.. Apart from being unlikely to hold the bolt parallel to the axis, it provides insufficient length of grip and the pressure of the tool will push it out of line, possibly damaging it and the tool.

(How do I know? Guess!)

That length though. Surely not 40 cm but 40mm? For we of inch-age that's roughly 16 inches to 1-5/8 inch!

i would not use Jason's suggestion of supporting any threaded material by a fixed steady. It will provide support but unless a roller-steady, it won't do the steady's bearing surfaces any good.

Parting-off threaded material is of course feasible but I would advise using minimum projection of blade from holder and a very careful feed (without rubbing). The thread will try to bend the parting-tool, risking it digging in or even breaking..

I would simply saw the bolt to length then face the end - or if an accurate end is not necessary, file it to remove the sharp edge.

.

However I read your post from the start as turning a length of the bolt down to a smaller diameter, with a properly-faced end.

So for that I would use the holding method described earlier (a simple collet or a pair of lock-nuts for maximum holding length), and tailstock centre for support.

not done it yet23/09/2022 11:11:01
7517 forum posts
20 photos

Non comprendez. What exactly are you trying to pull? I think you are trying hard to make things difficult for replies and actually doing the job.

The sensible way would be to cut a centre and support with a tailstock centre?

Edited By not done it yet on 23/09/2022 11:19:07

MadMike23/09/2022 11:20:38
265 forum posts
4 photos

I am with NDIY here. just what are you trying to make? A sketch with dimensions would be of great help to the gathered throng.

However with the limited/inaccurate information available I think you are all approaching this from the wrong direction. Chucking a bolt head, use of an angle grinder etc etc? Really? I would simply get a length of hexagon bar, turn down the end to size, the reduce the diameter along itds length and simply cut the desired thread. Then reverse the bar and part off to length.

So, Philip Hardy, a sketch please in case I missed something.

Philip Hardy23/09/2022 11:23:09
21 forum posts
2 photos

The bolt is part of a puller to remove a clutch assembly on a lawn mower, I'll post a photo of it later

Philip Hardy23/09/2022 11:28:32
21 forum posts
2 photos

here's the link showing the tool I am looking to replace the bolt

https://www.ebay.co.uk/itm/275427388958?hash=item4020c06e1e:g:nFcAAOSw2~ZbxkVq&amdata=enc%3AAQAHAAAAoPnmauL7EoHKszkqyYnGk%2FV1a3DpU2KwDS8xPRHD4cJSnXKvwdvkb1cqDEDvax3GHgxS%2FEk7ao3zrhxhTe6xgwAuyElOVA%2FsaSUktZxy6E9vgiYuX1mpYZQznFCJJw60cmw8PcoPxOs4HaetihVeGXFaN%2BTrF25dHY6%2FQ98nVIcfZM9Yym9q5HTkzkr%2FpcZw7ckv14sL%2FW1SLIvqxREtaGc%3D%7Ctkp%3ABk9SR4L3jJ7tYA

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