The Measuring Instrument
A Fineness of Grind Gauge measures the prevalence of coarse particles in a variety of substances, so that performance of a milling or dispersing operation can be monitored to avoid costly over-grinding. A Grind Gauge is an easy to use, and relatively inexpensive production and quality control instrument that enables the manufacturer and user to check for unwanted agglomerates as well as particles that are too large.
The Process
Material to be checked is distributed uniformly by drawing a straight-edged scraper from the deep end to the shallow end of the gauge. Particles or agglomerates too large to pass between the moving scraper and the gauge path are revealed as “scratches”, “points”, or “speckles”. Readings require minimum time and technical skill, yet produce numerical results which can be recorded and reproduced for comparison.
Scale and Units of Measurement
Mils – One Mil is .001 inches.
Microns – Micron is usually rounded to .00004 inches for practical purposes. 25 Microns is equal to 1 Mil (.001 inches).
Hegman – The Hegman Scale is the most common scale used in the paint industry. At the 8 (eight) Hegman (H) calibration mark the depth of the path is .000” (0 Mils) or no depth and at the 0 (zero) Hegman (H) calibration mark the depth of the path is .004” (4 mils).
NPIRI Scale – Designed for ink gauges, The NPIRI scale begins at 0 (zero) and extends to 10 (ten). The depth at 10 NPIRI is .001” (1mil). The scale divisions are equal to one tenth of a mil or 2.5 microns.
Specifications of Fineness of Grind Gauges
* Path is length of calibrated section only
** Included scraper is an A-1 440-C
| Catalog # | Block Size (approximate) | Path Size * | # Paths | Scales | Range | Scraper Included ** | Link |
|---|---|---|---|---|---|---|---|
| 25 | 1/2 x 2-1/2 x 4-3/4″ | 1/2 x 2″ | 2 | Hegman Mils | 8-0 0-5 | Yes | Buy Online |
| 45 | 1/2 x 2-1/2 x 6-3/4″ | 1/2 x 4″ | 2 | Hegman Mils | 8-0 0-5 | Yes | Buy Online |
| 65 | 1/2 x 2-1/2 x 8″ | 1/2 x 6″ | 2 | Hegman Mils | 8-0 0-5 | Yes | Buy Online |
| 5251 | 1/2 x 2-1/2 x 6-3/4″ | 1/2 x 5″ | 2 | Microns Mils Hegman | 0-25 0-1 8-6 | Yes | Buy Online |
| 5252 | 1/2 x 2-1/2 x 6-3/4″ | 1/2 x 5″ | 2 | Microns Mils Hegman | 0-50 0-2 8-4 | Yes | Buy Online |
| 5254 | 1/2 x 2-1/2 x 6-3/4″ | 1/2 x 5″ | 2 | Microns Mils Hegman | 0-100 0-4 8-0 | Yes | Buy Online |
| 51 | 3/4 x 3-1/2 x 7-1/2″ | 2 x 5″ | 1 | Hegman Microns | 8-6 0-25 | Yes | Buy Online |
| 52 | 3/4 x 3-1/2 x 7-1/2″ | 2 x 5″ | 1 | Hegman Microns | 8-4 0-50 | Yes | Buy Online |
| 54 | 3/4 x 3-1/2 x 7-1/2″ | 2 x 5″ | 1 | Hegman Microns | 8-0 0-100 | Yes | Buy Online |
| PD-250 | 3/4 x 3-1/2 x 9-1/2″ | 1 x 6-1/4″ | 2 | Microns Microns | 0-50 0-250 | Yes | Buy Online |
| 9484 | 1/2 x 2-1/2 x 6-3/4″ | 1/2 x 5″ | 2 | Microns Microns | 0-50 0-250 | Yes | Buy Online |
| PB-20 | 1/2 x 2-1/2 x 9-1/2″ | 1/2 x 8″ | 2 | Mils | 0-20 | Yes | Buy Online |
| PB-30 | 1/2 x 2-1/2 x 9-1/2″ | 1/2 x 8″ | 2 | Mils | 0-30 | Yes | Buy Online |
| PB-40 | 1/2 x 2-1/2 x 9-1/2″ | 1/2 x 8″ | 2 | Mils | 0-40 | Yes | Buy Online |
| PH-125 | 3/4 x 1-1/2 x 8″ | 1/2 x 6″ | 1 | Microns | 0-125 | Yes | Buy Online |
| CMA-185 | 3/4 x 2-1/2 x 12″ | 1/2 x 10-1/2″ | 2 | Microns Microns | 0-105 80-185 | Yes | Buy Online |
| G-1 | 3/4″ x 3-1/2″ x 9-1/2″ | 1″ x 6-1/4″ | 2 | NPIRI Microns | 0-10 0-25 | Yes | Buy Online |
| G-2 | 3/4″ x 3-1/2″ x 9-1/2″ | 1″ x 6-1/4″ | 2 | NPIRI Microns | 0-20 0-50 | Yes | Buy Online |
| G-3 | 3/4″ x 3-1/2″ x 9-1/2″ | 1″ x 6-1/4″ | 2 | NPIRI Microns | 0-30 0-75 | Yes | Buy Online |
| SI-1 | 1/2″ x 2-1/2″ x 8″ | 1/2 x 6-1/4″ | 2 | NPIRI Microns | 0-10 0-25 | Yes | Buy Online |
| SI-2 | 1/2″ x 2-1/2″ x 8″ | 1/2 x 6-1/4″ | 2 | NPIRI Microns | 0-20 0-50 | Yes | Buy Online |
| SI-3 | 1/2″ x 2-1/2″ x 8″ | 1/2 x 6-1/4″ | 2 | NPIRI Microns | 0-30 0-75 | Yes | Buy Online |
| 6251 | 3/4″ x 3-1/2″ x 9-1/2″ | 1″ x 6-1/4″ | 2 | Hegman Microns | 8-6 0-25 | Yes | Buy Online |
| 6252 | 3/4″ x 3-1/2″ x 9-1/2″ | 1″ x 6-1/4″ | 2 | Hegman Microns | 8-4 0-50 | Yes | Buy Online |
| 6254 | 3/4″ x 3-1/2″ x 9-1/2″ | 1″ x 6-1/4″ | 2 | Hegman Microns | 8-0 0-100 | Yes | Buy Online |
| 625 1/2 | 3/4″ x 3 1/2″ x 9 1/2″ | 1″ x 6-1/4″ | 2 | Microns | 0-12 1/2 | Yes | Buy Online |
| 9318 Texture | .600″ x 2” x 6 1/2″ | 1″ x 3 1/4″ | 2 | Microns | 25-75 | Yes | Buy Online |
| SW-8 | 1/2″ x 2 1/2″ x 12″ | 1/2″ x 6″ | 2 | Microns | 0-125 | No | Buy Online |
* Path is length of calibrated section only
** Included scraper is an A-1 440-C
Specifications of Scrapers for Fineness of Grind Gauges
| Catalog # | Thickness, Width, Length | Description | Link |
|---|---|---|---|
| A-1 | 1/4 x 1-1/2 x 3-3/4″ | Two edges with .015″ radius making line contact. For 1-1/2″ through 3-1/2″ gauges. | Buy Online |
| A-3 | 3/8 x 1-1/2 x 4-5/8″ | Two edges with .015″ radius making line contact. For 4″ and 4-1/2″ gauges. | Buy Online |
| A-4 | 3/8 x 1-1/2 x 6-3/4″ | Two edges with .015″ radius making line contact. For FPBAA-C and some special gauges. | Buy Online |
| IA-1 | 1/4″ x 3-5/8″ | Wide with insulated handle for use with heated gauges | |
| B-1 | Footed or block-type scraper for 2-1/2″ wide gauges, one flat edge. | ||
| B-2 | Footed or block-type scraper for 3-1/2″ wide gauges, one flat edge. | ||
| B-3 | Footed or block-type scraper for 4-1/2″ wide printing plates, one flat edge. | ||
| Warren Block Scraper | Footed or block-type scraper for Warren wedge printing plates, one flat edge. |
Custom Gauges
Precision Gage & Tool Co has created thousands of custom gages since 1932 for customers in various industries. Please contact PG&T and we will be glad to assist you in determining which type of gage is best for you.