Fat Parallels Useful?

[SteveHGraham]

Is it worth it to get thick parallels? I use the thin ones. They don't really hold the work up once the vise is tightened, so I'm not totally sure what the advantage of the fat ones is. Is it just one of those versatility things that becomes obvious once you use the tool? I've never found myself wishing my parallels were thicker, but I guess anything is possible.

[DeMaxx]

They're all useful, it all depends on what you are attempting to do.
I have a box full of parallels of different "fatness" and height.
For clamping odd shaped items onto your mill table it is always nice to have a fat parallel to clamp to.

[BadDog]

First off, they are convenient to use and don't fall over. But sometimes you don't have room for them in the vise. The main place I use them is for clamping. Thin parallels simply don't work well. For clamping it's all about 1-2-3 blocks, wide parallels, knees, and so on.

[SteveHGraham]

I notice Shars advertises the same specs as Brown & Sharpe, for like 1/9 the price.

[BadDog]

I wouldn't be surprised if the provide a photocopied cert to "prove" it too. Then again, B&S for the last couple of decades has likely (seemingly) been getting their product from the same region, possibly the same shop, so who knows.

[Frank Ford]

Since there's so often a tendency to lift, even with a solid Kurt vise, I'm a bit unclear on the "need" for extreme accuracy parallels.

So, maybe I favor quantity over quality - I do like having a good selection of 'em, from fat to skinny, although I've yet to find much use for the 1/32" thick ones.

[Harold_V]

Since there's so often a tendency to lift, even with a solid Kurt vise, I'm a bit unclear on the "need" for extreme accuracy parallels.

All depends on the nature of work you must do. If you're working to tenths (not all that unusual), it's virtually impossible to achieve the goal if you're dealing with tools that have greater error. If, however, you have a reasonable window for error, yeah, it doesn't make much difference.

There are ways to compensate for slight errors. For example, if you're trying to achieve squareness, the head of a mill can be nodded to correct a small amount of error, assuming it's consistent. If parallels aren't closely matched, you lose the ability unless you ensure they never get exchanged with one another in the setup. Using air, that may or may not be easy.

I own no commercially made parallels. All of mine are shop made, and old as the hills. They are matched sets, held to a tenth. I can trust them to do the job in question.

Size of parallels isn't critical. There's absolutely nothing wrong with bastard sizes, so long as you have at least two of the size in question. In fact, it is often to advantage to have parallels that are unusual in height. Very useful for holding thin parts, keeping the top edge above the vise jaws. If they're not too tall, they can be used in conjunction with a second set, to establish a weird dimension in the vise.

I've yet to find much use for the 1/32" thick ones.

One place they can be very useful is when drilling a series of holes on narrow parts. Thick parallels are often in the way.
There are times when I could use thin parallels. Who knows----I just might purchase a set.

Harold

[SteveHGraham]

One place they can be very useful is when drilling a series of holes on narrow parts. Thick parallels are often in the way.
There are times when I could use thin parallels. Who knows----I just might purchase a set.

I can testify. I have 1/8" parallels, and they've already come close to getting in the way.

[BadDog]

Some time back I had occasion to make a small "run" of parts that used 1" x 1/2" hot roll for part of it, and that resulted in a fair number of short drops. These and others (down to 1/4") were fly cut as pairs to make sacrificial parallels. For places where I don't need better, these are great for drilling near the edge, or anywhere else.

[art.h]

Just a usefull tip, steel banding mateial cut to length and shaped liike a recurve bow will hold thin paralles solidly against both vise faces, help keep chips from getting behind parallels. It acts like a spring and keeps everthing in place during part changes.

[SteveHGraham]

Guess I'll cancel my order for a Hardinge .00000001" tolerance parallel holder.

[Harold_V]

Just a usefull tip, steel banding mateial cut to length and shaped liike a recurve bow will hold thin paralles solidly against both vise faces, help keep chips from getting behind parallels. It acts like a spring and keeps everthing in place during part changes.

Yep. A heavy spring is also useful for the same purpose. I keep a variety of them for use in that capacity. Valve springs or clutch springs are a good example, although a wider range of lengths is useful.

I use an air hose routinely when machining. A heavy spring doesn't get displaced with an air blast. Nor do the parallels.

Harold