Harold Hall

With the outer diameter parallel, now very lightly face the outer ring of the end. This is essential as only by turning the outer diameter and the end in succession can the accuracy of the base relative to the sides be assured. Finish by parting off as close to the chuck as is possible. Now make a second square making it the same diameter and length as the first. Neither is critical but getting the diameter within say 0.01mm may be of help subsequently. If you do not achieve this do not be overly concerned as it is of little importance.


The next task is to face the parted off end. Place the square in the three of four jaw protecting the machined surface using a strip of thin copper wound round it, check that the end is running reasonably true, visually should be a sufficient check. Now, using a small centre drill, centre drill to a diameter of no more than 4mm and support with tailstock centre. Face the end as close to the centre as is possible and make substantial chamfer on the end, say 3mm wide. The chamfer indicating which is the non working end.


Next, drill though to make contact with the hole drilled from the other end. However, as the drill may have wandered  over that length use a drill one or two sizes larger than originally used. Repeat for the second square. Drilling the hole should remove the small portion that did not get faced.


You will not want this precision item going rusty so wipe them an oily rag but then wiping with a dry rag to remove the surplus.


Why then have you made these items. Probably the most likely use is an alternative to an angle plate, especially useful if an angle plate is being machined from a raw casting for use in the workshop and another is not available to support it, Photograph 2. Mounting the angle plate diagonally , as shown in Photograph 3, will result in the end being perfectly square to both faces.


Photograph 4 shows one being used to set a piece of angle upright, for machining its end, whilst being held on the workshops angle plate. Such a set up is particularly useful if a number of identical  parts are to be made as it is much quicker than using an engineers square to set each one upright. Where heavy machining is involved then a square can give added support.


Finally, Photograph. 5 shows a shorter one being used to set up a piece of steel in the vice. This can be easier than using a small square which may slip between the vice jaws.


See the page on making an Angle Plate using cylindrical squares.

Angle Plate, machining, using a cylindrical square
Angle Plate, machining, using a cylindrical square
Cylindrical Square, workshop grade, using
Cylindrical Square, workshop grade, using











Workshop Projects