All-metal lead holders
Having heard that the lead holders occasionally break in use, I’ve replaced the part-metal and part-plastic lead holders with all-metal lead holders. These have proven to be durable.
New replacement sandpaper discs
The stack-of-five sandpaper discs used with the H-501 dressing disk (part number H-501-20) is now replaced by a higher quality “single disk at a time” version using a better adhesive. The disc kit fits into the H-501 carry case, so you will always have spares on hand when you need them.
You can now purchase replacement disc kits (five sandpaper discs, without the plastic disk they mount on) instead of having to replace the entire dressing disk. Disc kits (part number H-501-20R) sell for just $11.
The plastic disks (H-501-20) are, of course, still available; and they come with the five sandpaper discs.
At long last, I have found a direct source for the #222 LED bulbs, so Micro-Metrics is able to lower the price of the LED bulb to $1.80.
Upgraded H-501 Pencil Hardness Gauge
The H-501 Pencil Hardness Gauge has been upgraded. In place of the previous gray plastic body, the H-501 (and the dressing disk base) are now made using a higher-quality white plastic. The lead holders now come with all-metal barrels, instead of the older version that was part metal and part plastic.
Technical Data Sheets
There is a new webpage on the Micro-Metrics website with links to the Technical data sheets that come with Micro-Metrics products as PDFs in printable form. (I have reformatted them so they can be printed on 8-1/2″ by 11″ paper.) There is also a white paper entitled: “Measuring: the Geometry of the Tooke Gauge.” (A customer requested a TDS on how to replace the lightbulb, which is also there now.)