adjustable parallels

[EmilioG]

I've been looking to buy new steel parallels for the BP mill I use at work. The adjustable ones like Starret or B&S seem expensive for they do not come in pairs. How are they used and do you need two sets? How would you make to adjustable type the same height? Should I just get a regular set in pairs? Thanks

 

[JimDawson]

A standard parallel set would be your best bet for general use. There several thicknesses available, the most common are the 1/8 inch thick type. Standard parallel sets come in pairs, normally heights range from 1/2 to 1 1/4 inch tall, in 1/8 inch increments.

You adjust the adjustable ones by setting them with a micrometer or caliper. Normally used when you need an exact height.

 

[mikey]

Adjustable parallels aren't used often for work support in pairs. As Jim points out, standard parallel sets that do come in pairs are far more commonly used for support in the machine vise. However, adjustable parallels come in handy when you need to measure the width of a slot very precisely. You lay one in a slot and open it up to width and then measure the parallel with a micrometer. Another use is as a fairly accurate space block, say for use with a sine table.

One set of standard parallels that I find really useful are the thin sets. They allow you to drill a piece very close to the edge and there are times when this is invaluable. They are usually offered in steps of 1/16" instead of the standard 1/8" increments; this comes in handy when you are milling a thin piece as you can often get that piece close to the top of the vise so you can cut it.

Personally, I think you need both standard and thin sets. The adjustable ones can come as your budget and need allows.

 

[chuckorlando]

I use thin ones most often. Thick ones are good on thin stuff where only one will fit in the vice. Adjustables are good for off setting stuff an exact amount. Could be used for a quick and dirty sine set up. Setting quill depth stops. Setting work just the right height in the zice. Like a mill jack to support a low section.

I dont own any, just thinking as I want some. Had I not just payed for a power feed I would have snatched Bills he just sold

 

[Bill Gruby]

Adjustable Parallels are used for measuring, not to hold things in the mill. They do not come in matched pairs like the others. You want Parallel Sets for your use.

"Billy G"

 

[Fabrickator]

I use a std. 1/8" Parallel Set. The other day I was wishing I had an adjustable set for setting up thin flat plate stock in my mill vice, so I shimmed under the plates to get the proper height. It doesn't happen often so it's not be worth investing in them

I keep a cookie tin full of different thickness shims I've made for mill & lathe setups from bits of beer can to 3/16" and below aluminum flat stock in varying lengths to different thickness of modeling plastics. Never throw away a shim once it's cut, you'll need it again someday.

 

[EmilioG]

Good stuff. Thank you. I'm glad I didn't buy those Starrett adjustable parallels.
I'll get the 1/8" and 1/16" pair sets instead.

Any good brands or suppliers? How much should I spend for a good 10 or 12 pair set?
Btw, I need to remember to pull out the parallels when I drill something. I damaged two
of my bosses parallels the other day. oops. ( I will replace them),

Thank you all.

 

[mikey]

Unless you are determined on buying an expensive set I would suggest import sets from any of the major suppliers - Travers, MSC, Enco, etc. Their cost is reasonable and their precision is acceptable for most shop work. Expect that a full set of thin parallels may cost more than the typical 1/8" sets - you're getting about double the number of thin parallels per set.

 

[gr8legs]

+1 on getting the relatively inexpensive imported sets - but be aware that they are definitely 'sets' that are ground together to size.

They may not be exactly the stated dimension but each two of a pair in a set are matched to each other. This becomes critical if you have more than one set and try to mix and match between them... flatness flies out the window. <- Voice of Experience

Stu