About Parallels (the holes)

[graham-xrf]

This forum search has oodles of good advice on parallels, but..
Aside from being able to hang them up on a nail, why do some have a pair of big holes in them?

 

[Jim F]

Are you referring to the thicker ones?
I suspect for weight reduction.

 

[SLK001]

They are for what's called "keepers". Below is a pic of a set. If you've ever had to struggle with a setup using parallels, you'll appreciate having a pair or two of keepers.

 

[graham-xrf]

Are you referring to the thicker ones?
I suspect for weight reduction.

No - not at all. A very common set of often used parallels has 8 pairs or 10 pairs 1/8" thick, in various sizes from about 1/2" or less. As the size gets broader than about 3/4", they have holes.

A random picture fro eBay shows some.



Oops - thanks @SLK001 . Your posting arrived while my picture was loading

 

[graham-xrf]

They are for what's called "keepers". Below is a pic of a set. If you've ever had to struggle with a setup using parallels, you'll appreciate having a pair or two of keepers.


View attachment 347717

So - to keep them in place, and stop them falling over while one is trying to get the other stuff set up?

 

[C-Bag]

So - to keep them in place, and stop them falling over while one is trying to get the other stuff set up?

Yup, if not in a vice. They are the wrong orientation for in a vise though.

 

[Janderso]

I like rubber bands too.

 

[Winegrower]

Or small disk magnets.

 

[Manual Mac]

Or chunks of rubber hose

 

[KMoffett]

I like to use strips of metal strapping tape, bent into a "V", to hold the parallels in place. Free and easy. I also occasionally use them bent in shapes as 0.500 wavy parallels to miss drill holes. Take a Mic and measure the width. They're incredibly uniform along their length. Also, all 10 of my parallels have pairs of holes of varying sizes.



Wikipedia: Parallels: " Parallels commonly have a series of holes drilled on the 'front' face - allowing them to be used to position a workpiece or secured using t-slot clamps, and a countersink on each side to remove any sharp edges. "