MTFCA Forum

Ford Motor Company acquired a Swedish company that produced reference blocks in steel to be used for calibrating measurement equipment.
What was the name of that Swedish company?

Blocks made by Carl E. Johansson


Ford Industries info:

Johansson gauges?
1896 Swedish machinist Carl Edvard Johansson.
gage blocks, Johansson gauges, slip gauges, or Jo blocks.
Oops, Dan got there first.

Thanks both!

In 1884, Carl Edvard Johansson attended my alma mater, Gustavus Adolphus College in St. Peter, MN before returning to Sweden.

In 1932, the college gave him an Honorary Doctor of Science degree.

A year or so ago I was helping out with an estate sale. Amongst the items there was a completely mint set of Jo blocks, still in their original , again mint case. There was a typewritten note saying that they were made for inspection purposes and NOT to be used for calibration of line machinery. The note added, Made by Johannson for the Ford Motor Company. A machinist relative of the deceased collared them with delight.
Regards David Powell

David Powell wrote: ↑

Sun May 28, 2023 4:05 pm

A year or so ago I was helping out with an estate sale. Amongst the items there was a completely mint set of Jo blocks, still in their original , again mint case. There was a typewritten note saying that they wereMade for inspection purposes and NOT to be used for calibration of line machinery. The note added, Made by Johannson for the Ford Motor Company. A machinist relative of the deceased collared them with delight. Rgards David Powell

Even today, they're made in different grades of accuracy and of different materials. The most accurate sets are inspection grade, or "master sets" and are never to leave the inspection room. "Working sets" are for use on the shop floor. All sets should have their calibration report along with them at all times. Since nothing is perfect, each block may be "off" several millionths of an inch. Big deal, right? Yup, it's a big deal when you have many such blocks stacked up and the additive effect of the error begins to impact the accuracy of your measurements. That's why the calibration record is so important. It allows you to know and to compnesate for the stack-up error so that your block stack has a known dimension, within millionths. I guess that's more than anyone asked for so I'll stop here...