Using Toolmakers Buttons

The use of buttons goes back well before my time and its about 40yrs since I last used mine in industry. Mine were made in the toolroom amd were hardened and ground.

There were commercially available ones and which had one button longer than the others. I think the practise at the time was more or less to copy commercial ones.

The longer button was occasionally used when a particular hole was needed to form a datum position and identify it accordingly.

I do strongly suspect however, that this may well not be their intended purpose, as I said they go back in history some time. Perhaps others may know.

Edited By MalcB on 06/02/2017 16:24:35

So it can be set, or indicated, when other button(s) are close by.

Andrew

👍👍👍

'So it can be set, or indicated, when other button(s) are close by.'

Obvious, when you know! Thanks.

Dave

One early purpose, but possibly not the only one for toolmaker's buttons, was to establish datums for accurate boring of dowel and punch holes in dies for sheetmetal work. Before DRO's and jig borers came into use for diemaking, buttons were the only accurate way to establish the datums. The toolmaker would align the die set on a surface plate vertically with the guide pins resting on accurate parallels. Rough centres marking for tapdrill and tapping for the buttons was done using height gauge and scriber, followed by centrepunching, drill and tap off the surface plate. The buttons would be fitted and the die reset on the parallels on the surface plate. The buttons would be set to correct dimensions using gauge blocks/height gauge/test indicator off the surface plate vertically and the datum guide pin horizontally. Buttons were tapped into correct position and rechecked with the test indicator. When the buttons were set in the correct final locations and snugged down, the die set would be placed on the lathe on a faceplate with a die shank chucked in the four jaw chuck and the first hole zeroed up on the location of the first button using the test indicator. The first hole was then bored to size at the same centre as the button. Other holes used same method. Work accurate to less than .0002" was regularly produced by these simple methods. I was taught this by an old toolmaker who still did it the old way for very small dies or if newer machines were tied up. I later read about it in a reprint book about toolmaking in the early 1900's. JD