Precision NOGO Thread Plug Gauge (Tol. 2B) - UNC 3" x 4

• Use for functional GO and NO GO inspection of threads in quality control and production checks.
• Use to verify internal threads after tapping, thread forming, or rework operations.
• Use in incoming inspection to verify supplier parts against drawing requirements.
• Process: manual driving or assisted driving depending on your holder and machine setup
• Use: thread cutting, re tapping, and thread cleaning depending on condition

Note Apply the gauge without force and keep the gauging surfaces clean to avoid false results.

• Reduces interpretation variability compared with free hand measurements.
• Supports process capable inspection routines in production and incoming goods checks.
• Provides a fast pass fail decision without calculations or measuring equipment.
• GO and NO GO ends help detect oversize and form errors that affect assembly.

• Does not deliver a measured value, only an acceptance decision based on limits.
• Requires clean threads and careful handling, so it is not ideal in heavily contaminated environments.

1. Clean the thread on the workpiece and remove chips, oil, and burrs.
2. Check that the gauge type and thread system match the workpiece specification.
3. Apply the GO side first and turn or screw it in by hand without force.
4. Apply the NO GO side and confirm it does not enter beyond the allowed engagement.
5. Record the result according to your inspection plan and isolate nonconforming parts.
6. Clean the gauge surfaces and apply light protection against corrosion before storage.

Scope of supply is defined by your order confirmation and delivery note.

• Product type: Plug gauge
• Thread system: UNC
• Tolerance class: 2B
• Gauging side: NO GO

What does GO and NO GO verify in thread inspection

GO verifies functional assembly at the maximum material condition, while NO GO verifies that the critical diameter does not exceed the limit. Together they provide a fast acceptance decision for production control.

Do thread gauges measure the thread size numerically

Thread gauges provide a pass fail result based on limits. Use measuring equipment when you need numeric values for process capability studies or tool offset decisions.

How do you choose between plug gauge and ring gauge

Use a plug gauge for internal threads and a ring gauge for external threads. Select the thread system and tolerance class to match the part specification and the mating component.

What can cause a false fail during gauging

Contamination, burrs, plating build up, or thread damage can block engagement and create a false fail. Clean the thread and inspect for damage before declaring a part nonconforming.

How do you protect gauge accuracy over time

Protect the gauge from impact, store it in a protective case, and keep it free of corrosion. Follow your quality system for inspection and recalibration practice.

Where can you find additional gauge information and standards context

Use the gauge catalog for product overview and selection. VG 23 catalog as PDF