How-To
Ten Questions to Ask When Buying Ring Gages
While the quality of cylindrical ring gages can vary depending on the manufacturer, customers often treat these gages as commodity items. As a result, the primary question that customers ask is, "What is your price and delivery?" In reality, that should be the last question asked. Here are several questions you should pose first, to ensure that the gages you purchase truly meet your company's requirements and industry standards.
- What material is used to manufacture the ring gages? (Good-quality tool steels such as 8620 or O6, heat treated to minimum 62 Rc)
- Do you inspect incoming material for adherence to hardening specifications?
- After heat treating, do you stabilize the material? (Cycling from -130°F to 300°F)
- Are your gages precision lapped by hand?
- Do you inspect your gages in a temperature-controlled metrology laboratory?
- What is the sampling of the gages you inspect? (Every ring should be inspected before shipment)
- Will you certify my ring gages? (ISO and quality programs require documentation)
- Do you certify both class and size? (Class = within tolerance band; Size = actual deviations at 6 calibration points)
- Does the certification contain a Statement of Uncertainty?
- What is your price and delivery? (Ask this last)