The SCF-502 Setting Fixture, CF-540 Size Setting Adaptor, and GR-3000 Dial Bore Gauge are used together to set and calibrate the gauge for precise bore measurement in engine or machine components.
SCF-502 Setting Fixture
The SCF-502 is a heavy-duty, stress-relieved cast-iron fixture with lapped carbide micrometer anvils and a built-in magnifier for accurate setup. It provides a stable reference surface and allows the gauge to be set without removing it from its storage case. The fixture includes multiple "nest" assemblies for different Sunnen gauge series (GA-4000, GR-6000, GR-9000) and can be used inside or outside the case. It is used to position the gauge's probe so the micrometer spindle is aligned with the bore being measured.
CF-540 Size Setting Adaptor
The CF-540 is a size setting adaptor that centers the gauge's probe between parallel reference surfaces. It works with the SCF-502 to ensure the probe is perfectly aligned with the bore's centerline, which is critical for accurate readings. This adaptor is typically used when the bore is large enough to require a separate size setting ring.
GR-3000 Dial Bore Gauge
The GR-3000 is a Sunnen Dial Bore Gauge designed for measuring bores to within 0.200" of the bottom of a blind bore, with a .0001" reading. It uses wear-proof carbide balls and an adjustable centralizer to maintain consistent contact with the bore wall. The GR-3000 is set up using the SCF-502 fixture, and the CF-540 adaptor ensures the probe is centered.
Typical Workflow
- Prepare the fixture: Clean the micrometer spindle tip and select the correct gauge and gauge point for the bore size.
- Set the probe: Place the GR-3000 on the SCF-502 base, aligning it with the bore.
- Center the probe: Use the CF-540 adaptor to center the probe between parallel reference surfaces.
- Adjust and lock: Use the quick-setting wrench to lock the micrometer spindle in place, ensuring the reading is stable.
- Measure: Insert the probe into the bore and read the dial bore gauge for precise bore size.
Why They Work Together
- The SCF-502 provides a stable, repeatable setup platform.
- The CF-540 ensures the probe is centered, reducing measurement error.
- The GR-3000 delivers the actual bore measurement with high precision.
This combination is common in engine rebuilding, machining, and quality control operations where accurate bore measurement is critical.