This Barcor chamfer checking dial gage will give you a direct reading of the outer diameter of a chamfered hole. The larger gages such as the one shown above, have 3-winged plungers. Smaller gages are also available with full conic plungers.
- The Chamfer Gage only measures the top major large diameter of the chamfered or tapered hole. Hence, when you put the three blade Gaging Plunger into a sharp cornered (0º) Master or part, the gage reads the top diameter, which in this case is a straight hole. As you use it on a chamfered part having an angle less than the angle of the Gaging Plunger, the gage still picks up only the top major diameter, and so any angle up to the 90º included is correctly measured. Mind you, we are NOT measuring the angle or the depth of the chamfer, just the top diameter. Likewise on the 90º-127º Models, any angle from a straight hole to the 127º will be read correctly. So WHY have two Models? This is because the 90º has a 2:1 ratio and the shallower (harder to centralize and read) 127º has a 4:1 ratio and correspondingly an indicator twice as sensitive. Since most chamfers are 45º (90º included) the 90º gage is better and easier to use.Two forms are available: for chamfers with an angle of less than 90° and for chamfers with angles from 90° to 127° — usage desciption as provided by the manufacturer
The standard dial indicator is graduated in .001" but also available with .0001" digital or .0001" mechanical graduations. The accuracy for reading chamfers is ±.001" on 0-90° models and ±.002" on 90-127° models, regardless of which indicator you use.
The base of the Chamfer Gage is manufactured by Barcor (USA) but the dial indicator varies from supplier to supplier. You'll most often find this tool with a Starrett indicator or a CDI indicator, usually with a vanity dial. AccuPro Gold Chamfer Gage, SPI Chamfer Gage, Starrett Chamfer Gage, Dialsink (Brunswick Instrument) and the Dyer Chamfer Gage are examples.
It's a sturdy gage with a cleverly simple design. It does require "mastering" and this is done as follows: on the back cover of the gage you'll find the words "Set To" followed by a value, such as .020. Now it's a matter of setting the gage to this value while it's being held flat on a surface plate (the plunger pushed all the way in). We suggest you inscribe this value into the metal or plastic back cover because the label will eventually wear off. Unless you've lost this value, no other setting masters are needed.
* The 0-1/2" model is rarely in stock and may require up to 6 weeks for delivery. May we suggest you get the 0-1" version instead? It will give you a wider measuring range and it costs less. Model 1090 is usually in stock.
**While larger chamfer gages have 3-point contact with a 3-winged plunger, model 0090 FC and 5090 FC has full conic contact giving greater reliability. This is often the gage preferred by the aeronautics industry and is usually in stock.