1944 Ford Jo block set no. 1-B grade/tolerance???

[Mill Lee farm]

Hello everyone,
I've got an oppertunity to buy an 81 piece Ford C.E. Johanasson Gauge block set but I'm trying to determine the grade/tolerance to compare to more recent equipment. This will help me decide the value to me and what to offer.

I have faith that this old set (that is is very nice condition!) is of higher quality that a more recent workshop grade B (alt: 3 or AS2 depending on the standard) set, but I want to make sure.

The only apparent information is on the tag: Standard Set No. 1-B, purchased 1944


Is the 1-B a grading? Or is it a product code/set number?

What would the be the lowest grade we could expect for Ford Jo blocks?

Thanks for your quick answers in advance! Wish me luck!

 

[Deleted member 69715]

Gauge Block Grading

Read here. Good set for what a lot of us might use.

 

[Mill Lee farm]

Thanks for the link! Being a Wiki page I’m surprised I hadn’t seen before. I did see a lot of the same tolerance info in many other places. The concise history was very welcome!

So I really have the feeling that the 1-B is a part number. But maybe the B in part number references the grade B of the set? IDK.

I also came across some info suggesting that all grade A and AA were plainly marked as such on every block. Grade B was left blank. So the theory is thst if you find a set of Ford Jo blocks that are NOT marked A or AA then they are grade B

Some other similar gauge block labels I found on the web:





Not sure I’m getting the set. They’re in really nice shape and the non-machinist seller is convinced they’re worth $ to a collector. Probably not wrong but I’m not in the market for ‘collector’ prices lol

 

[Deleted member 69715]

That "collector" stuff is right up there with people who claim "vintage" on everything they sell. Local nutcase is tying to sell his 2012 Harley for ridiculous money...claims it's "vintage". Yeah, right.

 

[mmcmdl]

That "collector" stuff is right up there with people who claim "vintage" on everything they sell. Local nutcase is tying to sell his 2012 Harley for ridiculous money...claims it's "vintage". Yeah, right.

I consider myself as vintage and also a collector . I'm old and have plenty of useless junk .

 

[projectnut]

I'm pretty sure the letter B is the grade of the blocks. They were originally categorized by letter as to their accuracy. At one time (early 1920’s to the late 1940's) Ford owned the rights to the Johansson gauge blocks and made them in Dearborn Michigan. They produced gauge blocks in accuracy levels AAA, AA, A+, and B. In this case the blocks may appeal to collectors as well as machinists since they produced by the Ford Motor company

Older tolerance designations
• reference (AAA): small tolerance (±0.05 um) used to establish standards
• calibration (AA): (tolerance +0.10 um to −0.05 um) used to calibrate inspection blocks and very high precision gauging
• inspection (A): (tolerance +0.15 um to −0.05 um) used as toolroom standards for setting other gauging tools
• workshop (B): large tolerance (tolerance +0.25 um to −0.15 um) used as shop standards for precision measurement

Newer tolerance designations
• 0.5 — generally equivalent to grade AAA
• 1 — generally equivalent to grade AA
• 2 — generally equivalent to grade A+
• 3 — compromise grade between A and B

 

[Mill Lee farm]

Yeah… I mean there are ‘collectors’ for everything but I didn’t think machine tools drew that big of a crowd. When I look at ebay stuff it usually seems reasonable anyway.

Of course if it has Ford on it then that might change things…

Anyway, I much prefer this set over a newer off shore B grade, but I’m not ready to pay a bunch more.

Which brings up another question for the group on ‘used’ vs new.

For realistic shop use, I assume that basically ANY type of corrosion or scratching etc on the ringing surfaces is unacceptable? It’s almost impossible to determine true condition through photos.

Can rusty gauge blocks still be trusted after some evaporust treatment? I would guess they may not ring properly anymore due to pitting, but the calibrated surface may still be intact for stacking or checking micrometer calibration etc?

 

[Mill Lee farm]

Figured I’d pop the facebook photos up here for all to see.
Interestingly, the case is apparently bakelite?!?

Also…. I JUST realized that some of them are marked ‘0’??? Or is that part of the serial #?

 

[Deleted member 69715]

Rust, gouges, dents; actually any maring of the surfaces render blocks little more than precision shim stock. Incredibly tough to "wring" them together that way. Which wrung together blocks are something I consider necessary for a proper calibration of a gauge or fixture.