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What Material for DIY parallels

Bshady

Plastic
Joined
Mar 31, 2019
Hey Everybody!

I'm new to machining! just got my first CNC mill and I already love it!

I am looking to make some parallels and I am not sure whether to go with aluminum or Steel.

Aluminum from Grainger:
GRAINGER APPROVED Aluminum Flat Bar Stock, 0.125" Thickness, 2" x 72" W x L, Alloy 6061 - 2EYV8'|'2EYV8 - Grainger

It is cheap, easy to machine, super soft so I won't damage endmills or anything else.

Steel from Home Depot:
https://www.homedepot.com/p/Everbilt-2-in-x-36-in-Plain-Steel-Flat-Bar-with-1-8-in-Thick-801807/204225718

I read on this forum that using a harder material means it won't lose its parallelism so fast.

I don't want to get the precision ground stock as I don't have the money for that yet.

What do you guys think? I'm kinda feeling like I want to go with the aluminum but What do I know!
 
Making parallels for your CNC mill will take some skills you don't have yet. On top of it, you'll need tool steel, grinding, hardening, metrology equipment and some other stuff like... parallels. :)

Just buy a set. A new Chinese set of 1/8"-thick parallels or a used set of a good brand can be bought for $30-$60 and will be more than sufficient for your needs. Any of them will be a way better and less expensive than anything you can make at this point. This is one of the basic precision tools you must have for milling.

And forget about Grainger, Home Depot, Walmart or Menards as your metal suppliers. You didn't buy your CNC mill from one of those, did you? :)

One of the best home shop machining Web sites I can recommend is HSM. I can guarantee you'll like it.
 
See if you can get hold of some old linear bearing slides and cut them to length with a grinder, they're ready hardened, ready ground and providing both parallels are cut from the same length they're the same size, here's mine:

P4010413.jpg
 
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I made a set of aluminum parallels one time, but they weren't made from "Grainger Approved" material so they didn't last longer than the one time,one part low tolerance job!!:cryin:
 
precision ground steel wrapped in paper in 18,24" length is common at tool steel distributors locally or order online from many places.
.
cut to any length you want. myself i prefer not hardened steel. for many jobs even cold rolled steel will do, cut from same bar its often within .001" that is even if it measured 1.499 as long as both pieces measure the same its usually ok
 
precision ground steel wrapped in paper in 18,24" length is common at tool steel distributors locally or order online from many places.
.
cut to any length you want. myself i prefer not hardened steel. for many jobs even cold rolled steel will do, cut from same bar its often within .001" that is even if it measured 1.499 as long as both pieces measure the same its usually ok

You can use just about anything.. but aluminum may nick up so not as good as steel. You might even use the wood paint mixing sticks that come in 1/8 and 1/4" thick and can be quickly milled to any size or angle you wish. And they are fairly straight and true, often .001 or so..

Wood is handy because you can set a part on it and drill/mill right through the part with no worry about your cutters .. then throw it away (the wood not the part). It can be shaped quickly to size or shape. Hard wood is better than soft.

Not a bad idea to have wood or fiber board table top you can set on your mill to do some fixturing. A back rail can help square perts or hep to set parts in place. Screw in place fixtures (Block-ins, clamp-ons, rail boards and vises) can be placed and removed to fixture another part/job.

Good to have a .001 indicator you can Quick-set on a mill to square and set a part or fixture. I say .001 because it is easy to see a half thou on that an most often that is close enough for mill work. Quick to set to a top or a side of a part or fixture. I think a dial is better than a test for a small mill.
 
Guys... First post on April 1st, with the name BShady (Be Shady)...

You guys need to drink some coffee before you reply...
 
I like to have my Teenager hold the workpiece while I Drill holes. The thinner the material the better.

Or I use toothpicks that are glued together for Parallels. OR just don't use them at all, overrated shop crap IMO. It's just a ploy to get you to buy them, they really aren't that convenient anyway.
 
55% Ni, 20% Cr, the rest is Mo/Co/Ti/etc....yuck.

Yup, should be real pleasure to work with.
I have it only in wire form but based on numbers it must be a real treat to machine.
3 times harder than HSS at cherry red temperatures for starters..
 








 
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