All Charts and Screens Feature the Sealed Image Process
The Sealed-image process was developed to give maximum life to our precision charts and screens. A thin sheet vinyl plastic is laminated over the artwork, thereby protecting the image from wearing off due to use or cleaning.
The lines on charts are made accurate to their center unless otherwise stated on the chart. Our basic line width is .004" to .005" (.1-.12mm).
Glass screens are used for new or replacement screens for optical comparators. The image is centered to the OD of the glass to .005". Glass screens are available only for 14", 16", 24" and 30" S-T Industries, Inc./SCHERR-TUMICO optical comparators. Glass screens are recommended when the artwork pattern will be used for all application.
Plastic overlay charts are recommended when patterns will be changed frequently. Plastic charts are available in any diameter up to 30" (760mm). The plastic material is dimensionally stable, non-flammable and resistant to oil. To avoid distortion, plastic overlay charts should not be stored above 140°F (60°C).
Cleaning - Clean Sealed-image charts and screens with glass cleaner, soap and water or isopropanol using a soft cotton cloth. Avoid harsh rubbing. Do not use paper towels or coarse cloths and do not use acetone, benzene, lacquer thinner or other strong chemicals, as they will damage the surface.
To order glass and plastic charts, use this part number format:
(Machine size, Inches)
|Example: 20X Radius/Grid Glass Screen for 14" Optical Comparator=74-0031-1425|
Important - When ordering glass replacement screens, please include the model number and serial number of your optical comparator.
Special Artwork - Custom artwork is available on request. We can combine standard patterns or produce custom artwork scaled from your drawings.
NIST Certifications - Accuracy certifications can be provided at an additional charge. Please request this at the time your order is placed.
|Catalog No.||Thread Type|
|74-*488||American National, 4 to 80 pitch threads|
|74-*489||Unified basic, 4 to 80 pitch threads|
|74-*490||ISO Metric, .25 to 6.0mm pitch threads|
|74-*491||UNJ Basic, MIL., Spec 8879A 4 to 80 pitch threads|
|74-*493||American National Taper pipe threads|
*NOTE: You must specify magnification lens being used on your comparator. To designate the magnification, insert the appropriate following number in this blank area: