Parallels

On older gear, it is sometimes easier to make something, and identify which end that it was in when cut. Then it will always be Parallel. Making a set of jaws that can attach or replace the jaws and then cut into them, the recess depth required. It is one advantage of the vices with the bolts going from the outside of the vice to retain the jaws, compared to the ones where the retainer is inside the vice holding area. I make temporary jaws often out of extruded ali, or just black bar m/s and use a thin 1/8 or 3mm ali jaw protector. all made from 1/4X1-1/2 or what ever is available. I don't use the extruded drawn bright bar, as that will curl if cut on one side etc.

Model engineering is often making just one of something, and sometimes having expendable jaws makes that part just the bit more easy.

Me too. I don't have a mill but for milling in the lathe on the vertical slide and for drilling on my drill press I often use HSS blanks as parallels.The little 1/8" ones are ideal for the tiny Myford milling vice, and can be stacked if needed.

I also often use pieces of key steel as parallels. It comes precision machined to size, square and parallel so ideal. And in a pinch you can drill or mill right through into it as a sacrificial parallel. Available from bearing suppliers. And it comes zinc plated too so never rusts.

I use sections of Ground Flat Stock, or Gauge Plate which I have either surface ground myself or had a local engineering firm grind for me. GFS is seldom dead on size, usually plus and on the thinner sections the edges tend not to be square with the width of the section. Hence why I have them ground.

Parallels to suit my particular needs are thus quite easy to make. The latest requirement with the Proxxon mill was for 50 mm long parallels. Not many firms are making this size. The parallels I made for my Emco FB2 were made 30+ years ago and show no signs of wear.

Regards

Gray,

I suppose it's heresy but I just use plain old bright mild steel. I doubt if the rest of my mill, vice etc is good enough to warrant super precision. If you always use two bits cut from the same length they are pretty good.

I feel a project is brewing

I have a nice set of parallels, somewhere. And quite a lot of bright mild steel strip.

I have never had any problems with the latter. The money saved on not buying parallels can be put to better use like bottles of wine,

JA

A selection of my parallels.

I have some round sets of 4 all of the same height about 8mm tall and 20mm tall usefull when holding castings etc. A pair of 1"x1/2" x 9" long a pair of 12mm x 25mm x 150mm long which do most of my heavy work. I have a set of adjustable Starrett parrallel which are useful to measure steps and slots as well as adjusting to support a job. I also have two pair of thin parallels so i can drill a job without hitting the parallels, these are 1mm x 20mm x 75mm long and 1.5mm x 25mm x 75mm long. I also hsve a few other general purpose pairs of parallels of various thicknesses that I have collected over the years. These are all hardened and ground whilst at work for various jobs. The thin pairs of parallels have a tendency to tip so I put a light 12mm diamiter spring between them when in use. You can't have to many parallels.

David

Just a quick update:

I bought the set from Warco for £85 inc next day free delivery.

Very impressed with the quality and accuracy

We have lots at the museum, many donated, and I find that however many sizes you have, it's always the size you don't have that you want to use.