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This article was first published in 2008.
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A bench vice is probably the single most valuable
tool you can permanently mount in place. If you can hold whatever you’re working
on firmly and steadily in place, you’ll find the outcome vastly better – in
terms of results, ease of use, and safety.
So what is there to know about a bench vice – all
self-explanatory isn’t it? Not really – let’s take a look.
Types
Bench vices come in a variety of shapes and sizes.
There are two primary aspects that determine a
bench vice’s size – width and opening depth. The vice is normally specified by
width alone – eg a “100mm engineer’s vice”. The ‘engineer’ bit means that the
vice is designed for metalworking rather than woodworking, while the ‘100mm’
refers to the width of its jaws.
Many people like the idea of starting off with a
small vice that screw-clamps to the bench. In short: don’t. In operation you’ll
find it unhappily sloppy – typically, moving around when you try to file or cut
an object held in its jaws. These vices are generally only low in strength, so
you will also not be able to apply sufficient clamping pressure to the
work-piece.
Instead, a 100mm vice of the sort pictured is an
excellent beginners’ vice. Its cost will be low but it is still large enough to
perform many useful functions. Even a relatively small vice like this should
have a base that allows it to be bolted to a bench and should have removable
jaws. Note that this design of vice does not allow long, wide items to be
clamped vertically.
This vice has two additional features – a swivel
base (red arrow) and an anvil surface (green arrow). Both sound really useful
but are not particularly helpful in real-world use. Unless tightened hugely, the
swivel base will tend to allow the vice to turn when high forces are being
applied (eg a steel strip is being bent to form a bracket), and the ‘anvil’ part
of the vice is hard to access – much better to get an old lump of railway line
or steel beam and use that when hammering items flat.
The next size up of vice is a 150mm design, and
after that you can get a 200mm vice – the latter getting very large indeed!
The best advice is to start with the 100mm vice
and then if you find you often need a larger vice, to buy a second vice with
wider jaws. Keep the first vice mounted – you’ll find it useful to have two
vices. An example of where having two vices is useful is when you have a job
carefully set up in one vice and then have a short-term need for another vice. This
occurs more often than you’d first think!
When upgrading to a large vice, you might also
want to look for one with offset jaws. This design allows you to clamp long
items vertically in the vice.
Cast
versus Fabricated?
Over
the years I have used both cast iron vices and those fabricated (ie manufactured
by being welded together from steel parts). Both types work well – I wouldn’t
worry too much about the construction, so long as the vice is from a recognised
manufacturer.
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Mounting a Vice
Strange as it sounds, mounting the vice is perhaps
the most important aspect of vice-use to get right. If the vice is mounted
incorrectly, it will be hard to use and may even be dangerous.
A vice must be mounted so that when you are
standing next to it, the top surface of its jaws is level with your bent elbow.
If the bench top is too low, the vice can be raised with a hardwood block.
If the vice is too high, you can stand on a rubber
or timber board. Having the vice at the correct height will allow much more
accurate filing and hacksaw cutting – your fore-arm will be able to move back
and forth horizontally.
A vice must be very securely mounted. This has
implications both for the way in which it is attached to the bench, and how
secure the bench itself is.
Some books recommend the use of coach screws to
attach a vice to a bench – but don’t! Instead, use heavy-duty bolts, nuts and
washers to securely bolt the vice to the bench. Large vices use four bolts,
while smaller vices may use only two.
It’s no use attaching the vice securely to a bench
if the bench can then ‘walk’! The heavier the bench, the better. If you’re
working with a bench that is not bolted down and is lighter than desirable, at
least make sure that it has a lower shelf on which weighty objects can be
placed. A bench that is not bolted to the floor needs to have a mass of at least
150kg if it isn’t to be easily moved around by objects being manipulated in a
150mm vice. If used to mount a vice, this bench should be bolted to the concrete floor. Note the 'feet' that can be used for this purpose.
As we’ve indicated above, vices are normally
mounted on heavy benches. But where on the bench? This is a deceptively tricky
question. As shown in this diagram, the parting line of the vice is best
positioned so that it very slightly overhangs the edge of the bench. In that
way, long items can be vertically mounted in the jaws of the vice – and that’s
even more important when mounting a vice with offset jaws.
Using a Vice
Vices use hardened and serrated steel jaws to grip
the work-piece. These jaws are removable and can be replaced if worn. In normal
use, make sure the jaws are kept tight.
The serrated jaws keep a tight grip on the
work-piece but they also inevitably mark it. So in most situations, the jaws are
covered with soft metal jaws. The easiest way of making these is to cut some
short sections of aluminium angle a little longer than the width of the jaws.
The work-piece is positioned within the jaws of
the vice and the vice just nipped-up.
The work is then rechecked for location, keeping
in mind that you don’t want your hand tool (eg a file) to touch the hardened
jaws of the vice. The vice is then firmly tightened by hand.
Normally the full width of the jaws is employed to
hold the work-piece (or the work-piece is centred, as here) but sometimes the
item must be positioned at one end of the jaws. Note, however, that doing this
frequently over a longer period will distort the jaws – as a result, the clamping
force will no longer be even across the jaws’ full width.
Use and Mis-Use
Normally in a section on use and abuse of a vice
you’ll find a bunch of points like: never put an extension lever on the vice
handle to tighten it up, never apply heat to an object clamped in the vice,
never use a big hammer to bend bar held in the vice. And so on.
But realistically, over a long period of using a vice,
it’s very likely that you’ll end up doing all of these things – not on a regular
basis, but when it’s required. Along with inadvertent touching of angle grinder
discs against the jaws, and normal wear and tear, over time the vice will lose
its effectiveness. The thread will get sloppy, the jaws will no longer be
parallel (or possibly even at the same height) and as the vice is tightened, the
jaws will change in angle.
When a vice gets like this, buy another. It’s
simply not worth working with a vice that is worn – too many stuff-ups then
occur. And, for the same reason, be wary of buying secondhand vices.
Conclusion
A well set-up vice is more than just another pair
of hands – it’s a pair of hands of immense strength and rigidity! Every workshop
– no matter how big or small – should have a good vice. It’s as simple as
that.
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