General > General Technical Chat
How much time to file down bolts ?
MathWizard:
I need to lower a CPU mounting bracket by about 0.7mm, and it sits on special bolts, that I would just have to file down. They are just some cheap steel, and only about 8-10mm in diameter.
I have hand files, and a belt-sander here (w/ sandpaper for wood tho),
So just off the top of someones head, how long would it take by hand file, to file down 0.7mm off a 1cm dia. bolt, an hour, many hours ? And there's 4 of them. Wish I knew someone with a lathe. And I'm not paying $80/hour tho.
I have a rough sharpening stones too, if the bolts are just mild steel, it shouldn't be too bad.
Someone:
With a belt sander? minutes each, the skill is not taking off too much!
... having done various mods on cooling systems in PCs to fit "odd" CPUs where they were never intended. Shimming is often easier.
nctnico:
Taking 0.7mm off is a matter of minutes with a suitable file. Typing your post likely has taken longer.
jpanhalt:
Are you asking about filing the head or threaded portion?
Let's assume you mean threaded portion. If so, be sure to put a nut on the thread above or at where you want to end filing. Then, when done filing, remove the nut. It will help dress the thread at the end so it can be reinserted more easily. I also do a little hand dressing for a really smooth reattachment.
Ian.M:
Assuming a sharp full sized fine cut file, with a good handle, (and not made of Chinesium), and the work rigidly clamped in a bench vice, you should be able to take off most of that 0.7mm in a few minutes each. Note this assumes ordinary mild steel or medium carbon steel bolts, not above bolt grade 5, and not specially hardened. Any alloy steel of high hardness or with a tendency to work harden would be *MUCH* slower.
A bigger problem is getting the filed down ends uniform and square. Measure often, and change your tactics when you've taken off 0.6mm on the low side. Mark the low spots with a marker pen then file the rest down to match, again checking the measurements frequently to avoid going too far. Ideally you should have around 0.05mm left to remove over the whole end of the bolt. Then you need to mount the bolts to a convenient sized flat plate in a square, and lap their ends all together to get them square and down to final length. Wet lapping with ascending number grits of Wet & Dry paper face up on a hard very flat surface (e.g. float glass on some sort of backing board) is probably the best way to go here. Again measure often and once it stops rocking, concentrate pressure on the highest corner or side, to take those bolts down faster to get them level. Finally, remove them from the plate and 'break' the edges or chamfer the last turn of the thread.
Navigation
[0] Message Index
[#] Next page
Go to full version