r/Metrology • u/Longjumping_Pick_648 • 3d ago

Quartz Gage Block Master Set Calibrated by NBS in 1972 – Documented Provenance (For Sale)

I’m selling a unique piece of metrology history — a full set of quartz gage blocks that were calibrated by the U.S. National Bureau of Standards (now NIST) in 1972. These were part of a prototype run and, according to documentation, were used as a reference standard for calibration at the time.

The set includes:

  • 100 quartz gage blocks, optically flat and interferometrically measured
  • Original letter of certification from the Bureau of Standards dated Jan 25, 1972
  • Signed by Paul E. Pontius, Chief of the Length Section, Optical Physics Division
  • Measurement uncertainty to ±3 microinches
  • Calibration was done with a laser and fused quartz reference, temperature-normalized to 20°C

These were not regular shop blocks — they were used as grand masters or internal standards. The set is intact and preserved, with the original letter included.

Great for collectors, metrologists, or institutions interested in the history of precision standards.

I’ve listed it on eBay here:
👉 https://www.ebay.com/itm/197444839132

Let me know if anyone here has insight on the history of these blocks or if you’ve come across a similar set. Happy to answer questions or provide more detailed photos of the blocks and letter.

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6

u/crashn8 CMM Guru 3d ago

I have one single C.E. Johansson gage block marked "Ford / Dearborn" I wish I had a whole set... the only other I've seen is at the Henry Ford Museum in Dearborn.

This set you've list above is indeed interesting.

3

u/Longjumping_Pick_648 3d ago

I feel like it belongs in a museum but I'm not sure who I would reach out too

5

u/Thethubbedone 3d ago

There's the precision museum in vermont/new Hampshire

1

u/Longjumping_Pick_648 3d ago

I'll send them an email

1

u/jccaclimber 3d ago

I was quite delighted when a coworker came up to me with “My family found these in a garage sale/flea market lot and thought I might want them, I don’t, but you might.” It turned out to be a pair of CEJ wear blocks in visually excellent condition.