McMaster-Carr logo
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    12 Products

    Threaded Ring Gauges

    Image of Product. Front orientation. Threaded Ring Gauges.
    Check a part’s external threads to make sure they fall within tolerance. You can use these for bolts, threaded rods, bits, and more. All gauges come with a manufacturer’s certificate of accuracy, also known as a certificate of compliance or a short form certification, that verifies the thread sizes are within tolerance.
    The part is within tolerance if it’s easy to thread a go gauge onto, but difficult to thread a no-go gauge more than two turns. Use a threaded ring gauge holder to keep two gauges on hand at once for faster inspection.
    Go Gauge—Go gauges check the maximum external thread size.
    No-Go Gauge—No-go gauges check the minimum external thread size.
    For Thread Fit—Threads have different classes of fit. Thread fit designates the tightness or looseness of the mating threads. For example, inch threads with a 3A fit have tighter tolerances than threads with a 2A fit.
    Go Gauge
    No-Go Gauge
    Thread Size
    Thread
    Type
    Hardness
    Material
    Thread
    Direction
    For Thread Fit
    Pitch Dia. Tolerance,
    mm
    Each
    Pitch Dia.
    Tolerance, mm
    Each
    Class X Gauges
    M30 × 1.5 mmMetric
    		Rockwell C60Tool Steel
    		Right Hand
    		Metric Class 6g
    		-0.008 to 023575A26300000000 to 0.00823575A2640000000
    M30 × 2 mmMetric
    		Rockwell C60Tool Steel
    		Right Hand
    		Metric Class 6g
    		-0.008 to 023575A2650000000 to 0.00823575A266000000
    M30 × 3.5 mmMetric
    		Rockwell C60Tool Steel
    		Right Hand
    		Metric Class 6g
    		-0.008 to 023575A2670000000 to 0.00823575A268000000
     

    Threaded Ring Gauges with Calibration Certificate

    Not only were these gauges calibrated in a lab, but they also come with a certificate that's traceable to NIST. The certificate, sometimes called a test report and long form certificate, details the tested measurements. They’re for checking a part’s external threads to ensure they fall within tolerance.
    A part is within tolerance if it’s easy to thread a go gauge onto the part but difficult to thread a no-go gauge more than two turns. Inspect faster by holding more than one ring gauge with a threaded ring gauge holder.
    Class X Gauges
    Image of Product. Front orientation. Ring Gauges. Threaded Ring Gauges with Calibration Certificate.
    Image of Attribute. Front orientation. Threaded Ring Gauges with Calibration Certificate.
    Go Gauge—Go gauges check the maximum external thread size.
    No-Go Gauge—No-go gauges check the minimum external thread size.
    For Thread Fit—Threads have different classes of fit. Thread fit designates the tightness or looseness of the mating threads. For example, inch threads with a 3A fit have tighter tolerances than threads with a 2A fit.
    Go Gauge
    No-Go Gauge
    Thread Size
    Thread
    Direction
    Hardness
    Material
    Certificate Type
    Pitch Dia. Tolerance,
    mm
    Each
    Pitch Dia.
    Tolerance, mm
    Each
    For Class 6g Metric Thread Fit
     
    Metric Thread
    M30 × 1.5 mmRight Hand
    		Rockwell C60Tool Steel
    		Calibration Certificate Traceable to NIST-0.008 to 03227A25600000000 to 0.0083227A2570000000
    M30 × 2 mmRight Hand
    		Rockwell C60Tool Steel
    		Calibration Certificate Traceable to NIST-0.008 to 03227A2580000000 to 0.0083227A259000000
    M30 × 3.5 mmRight Hand
    		Rockwell C60Tool Steel
    		Calibration Certificate Traceable to NIST-0.008 to 03227A2760000000 to 0.0083227A277000000
     
    back to top