# About Parallels (the holes)



## graham-xrf (Dec 18, 2020)

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?


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## Jim F (Dec 18, 2020)

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


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## SLK001 (Dec 18, 2020)

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.


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## graham-xrf (Dec 18, 2020)

Jim F said:


> 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


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## graham-xrf (Dec 18, 2020)

SLK001 said:


> 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?


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## C-Bag (Dec 18, 2020)

graham-xrf said:


> 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.


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## Janderso (Dec 18, 2020)

I like rubber bands too.


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## Winegrower (Dec 18, 2020)

Or small disk magnets.


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## Manual Mac (Dec 18, 2020)

Or chunks of rubber hose


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## KMoffett (Dec 18, 2020)

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. "


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## graham-xrf (Dec 18, 2020)

KMoffett said:


> 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.
> 
> View attachment 347736
> 
> ...


Yup - now that I have started looking, it seems anything and everything is used. Kitchen wash sponges which come with a side looking like ScotchBrite, squished up hose, white plastic stiff foam  from packaging boxes, inflatables, UniStrut nut springs, just about anything that can be stuffed in there to stop them falling over. I can see the utility of magnetic parallels.

Though a first purchase of the "most immediately useful" has thinner types, like 1/8" or 3mm recommended, there are some quite expensive boxed sets of 1/4", 3/8", 8mm, 10mm, 1/2", etc. For my own reasons, I had thought to get a pair, 150mm x 10mm wide that would be long enough to place right across the ways of my South Bend, and be wide enough to not just fall over. That will have to wait for a bit.

I can see the "wavey" sort as well. I have some reservations about them. I can see how adjustable parallels work. They have the property of being parallel, but lack being the same width, though can be adjusted so. I guess there are situations where they can be convenient.


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## hman (Dec 18, 2020)

It's actually pretty obvious.  The reason for holes is to allow a musically inclined machinist to make a Xylophone  


PS - the numbers along the right edge of the board indicate the amount of vise jaw remaining above the parallel.  Credit where credit is due:  the idea is from the January, 2020 (#289) issue of Model Engineers' Workshop. This magazine is published in the UK, so I'd guess that most forum members don't regularly read it. It was the "Readers' Tip of the Month," page 33, by Philip Hurst.


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## KMoffett (Dec 18, 2020)

I think I'll do that inside my plastic parallel box cover.


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## Mitch Alsup (Dec 18, 2020)

SLK001 said:


> 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



This seems to be a costly accessory that is not much more practical then 2 rubber bands.


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## Jim F (Dec 18, 2020)

Also , this.


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## 682bear (Dec 18, 2020)

Hman...

I like that... I think I will copy that idea...!

-Bear


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## talvare (Dec 19, 2020)

Mitch Alsup said:


> This seems to be a costly accessory that is not much more practical then 2 rubber bands.


I think some folks are missing the point of the "keepers". They are meant to keep parallels vertical and evenly separated when not being set up in a vise, such as just being set up on the mill table.

Ted


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## KMoffett (Dec 19, 2020)

Unless you are talking about other types of keepers, I think you may be missing the point. This is how those keepers with two rods and two plates are used:
Kurt keepers


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## talvare (Dec 19, 2020)

KMoffett said:


> Unless you are talking about other types of keepers, I think you may be missing the point. This is how those keepers with two rods and two plates are used:
> Kurt keepers


I have not actually ever seen the "Kurt" keepers before. But I have seen very similar pieces being used to keep parallels separated evenly while clamping a part onto a milling machine table. Thanks for posting the link to the Kurt keepers. Didn't know they made them.
Ted


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## KMoffett (Dec 19, 2020)

There are several companies that sell parallel keepers like Kurt's. Can you post a photo of or link to the type you have.


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## talvare (Dec 20, 2020)

KMoffett said:


> There are several companies that sell parallel keepers like Kurt's. Can you post a photo of or link to the type you have.


I don't own any parallel keepers. I have used all-thread rod with nuts to keep parallels in alignment when setting up a large part on the mill table. I got that idea from seeing it done by other machinists. The ones that I've seen were on machining videos and it appeared that the "keepers" were probably CRS rod of the appropriate size to fit the holes in the parallels and they were using lock collars to keep the parallels situated where they wanted them. I do agree with others here that those keepers like the Kurt device are kind of an expensive means of just holding parallels in a vise.
Ted


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## Mini Cooper S (Dec 20, 2020)

I made all of my parallels, none with holes.  When I have used ones with holes, I found them to be more difficult to to clean after use. Coolant and grinding dwarf can be a bugger!

Richard


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## KMoffett (Dec 20, 2020)

You have a dwarf? Does it do your grinding at night for you when you're asleep? I always wanted some to increase my production. Does it resent being cleaned out?


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## Manual Mac (Dec 20, 2020)

Heigh-Ho!


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## pontiac428 (Dec 20, 2020)

Lots of ways to build a better mousetrap... never gone wrong with a wipe with a rag and a drop of oil.  Instant keeper!


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