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

    Go/No-Go Threaded Plug Gauges with Handle

    Speed up thread tolerance checks—the handle on these gauges gives you a good grip to quickly thread and unthread go or no-go gauges. Use these gauges to make sure nuts, tapped holes, and other parts fall within tolerance. All are precisely manufactured to confirm thread fit. If the plug gauges wear down, you can insert new ones (not included) onto the taperlock handle.
    A part is within tolerance if it’s easy to thread the go gauge into the part but difficult to thread the no-go gauge more than two turns.
    Go/no-go gauges have both a go gauge on one end of the handle and a no-go gauge on the other to speed up tests. Go gauges check the minimum internal thread size. No-go gauges check the maximum internal thread size.
    Class X Gauge
    Image of Product. Double-Ended Taperlock Handle. Front orientation. Plug Gauges. Go/No-Go Threaded Plug Gauges with Handle.

    Double-Ended Taperlock

    Handle

    Calibration Certificate Traceable to NIST—Gauges with a calibration certificate traceable to NIST were calibrated in a lab. The certificate, sometimes called a test report or long-form certificate, details the tested measurements.
    For Class 2B Unified Standard Thread Fit—For inch threads, the higher the class number, the tighter the fit. Unified Standard Class 2B is standard and works for most applications.
    For Thread Fit—Thread fit designates the tightness or looseness of mating threads.
    Thread
    Size
    Thread
    Type
    Pitch Dia.
    Tolerance
    Hardness
    Material
    Features
    Choose a Thread Fit
    Each
    Go/No-Go Gauges
    5/16"-24
    		UNF
    		-0.0003" to 0.0003"Rockwell C70Chrome-Plated Tool SteelDouble-Ended Taperlock HandleUnified Standard Class 2B, Unified Standard Class 3B2366A525000000
     
    Go/No-Go Gauges with Calibration Certificate Traceable to NIST
    5/16"-24
    		UNF
    		-0.0003" to 0.0003"Rockwell C70Chrome-Plated Tool SteelDouble-Ended Taperlock HandleUnified Standard Class 2B, Unified Standard Class 3B3157A33000000
     

    Go/No-Go Left-Hand Threaded Plug Gauges with Handle

    A go and no-go gauge in one, these gauges check that left-hand threads fall within tolerance. Use them to confirm thread fit for nuts, tapped holes, and other parts. The taperlock handle speeds up tests, giving you a good grip to thread and unthread each gauge end. It also lets you swap out worn gauges for new ones (not included) on either end.
    The go gauge checks the minimum internal thread size, and the no-go gauge checks the maximum. A part is within tolerance if it’s easy to thread the go gauge but difficult to thread the no-go gauge more than two turns.
    Class X Gauge
    Image of Product. Front orientation. Plug Gauges. Go/No-Go Left-Hand Threaded Plug Gauges with Handle.
    Plug Gauges with Accuracy Certificate Traceable to NIST—Gauges with an accuracy certificate traceable to NIST include verification from the manufacturer that their thread sizes are within tolerance. The certificate is also known as a certificate of compliance or a short-form certification.
    Plug Gauges with Calibration Certificate Traceable to NIST—Gauges with a calibration certificate traceable to NIST were calibrated in a lab. The certificate, sometimes called a test report or long-form certificate, details the tested measurements.
    For Class 2B Unified Standard Thread Fit—For inch threads, the higher the class number, the tighter the fit. Unified Standard Class 2B is standard and works for most applications.
    For Thread Fit—Thread fit designates the tightness or looseness of mating threads.
    Thread
    Size
    Thread
    Type
    Pitch Dia.
    Tolerance
    Hardness
    Material
    Features
    Choose a Thread Fit
    Each
    Plug Gauges with Accuracy Certificate Traceable to NIST
    5/16"-24
    		UNF
    		-0.0003" to 0.0003"Rockwell C70Chrome-Plated Tool SteelDouble-Ended Taperlock HandleUnified Standard Class 2B, Unified Standard Class 3B7935N1030000000
     
    Plug Gauges with Calibration Certificate Traceable to NIST
    5/16"-24
    		UNF
    		-0.0003" to 0.0003"Rockwell C70Chrome-Plated Tool SteelDouble-Ended Taperlock HandleUnified Standard Class 2B, Unified Standard Class 3B7938N103000000
     

    Threaded Plug Gauges

    Test if internal threads fall within tolerance. These plug gauges are often used in nuts and tapped holes to confirm thread fit. For precision and accuracy, they’re manufactured to tight tolerances.
    Threads are within tolerance if it’s easy to thread a go gauge but difficult to thread a no-go gauge more than two turns.
    Class X Gauge
    Image of Product. Front orientation. Plug Gauges. Threaded Plug Gauges.
    Go Gauge—Go gauges check the minimum hole diameter.
    No-Go Gauge—No-go gauges check the maximum hole diameter.
    Accuracy Certificate Traceable to NIST—Gauges with an accuracy certificate traceable to NIST include verification from the manufacturer that their thread sizes are within tolerance. The certificate is also known as a certificate of compliance or a short-form certification.
    For Class 2B Unified Standard Thread Fit—For inch threads, the higher the class number, the tighter the fit. Unified Standard Class 2B is standard and works for most applications.
    For Thread Fit—Thread fit designates the tightness or looseness of mating threads.
    Thread
    Size
    Thread
    Type
    Pitch Dia.
    Tolerance
    Hardness
    Material
    For Thread Fit
    Each
    Go Gauges
    5/16"-24
    		UNF
    		0" to 0.0003"Rockwell C70Chrome-Plated Tool SteelUnified Standard Class 2B, Unified Standard Class 3B
    		7968N22000000
     
    Go Gauges with Accuracy Certificate Traceable to NIST
    5/16"-24
    		UNF
    		0" to 0.0003"Rockwell C70Chrome-Plated Tool SteelUnified Standard Class 2B, Unified Standard Class 3B
    		7968N11200000
     
    No-Go Gauges
    5/16"-24
    		UNF
    		-0.0003" to 0"Rockwell C70Chrome-Plated Tool SteelUnified Standard Class 2B
    		7968N5800000
    5/16"-24
    		UNF
    		-0.0003" to 0"Rockwell C70Chrome-Plated Tool SteelUnified Standard Class 3B
    		7968N5900000
     
    No-Go Gauges with Accuracy Certificate Traceable to NIST
    5/16"-24
    		UNF
    		-0.0003" to 0"Rockwell C70Chrome-Plated Tool SteelUnified Standard Class 2B
    		7968N14800000
    5/16"-24
    		UNF
    		-0.0003" to 0"Rockwell C70Chrome-Plated Tool SteelUnified Standard Class 3B
    		7968N14900000
     

    Go/No-Go Helical Insert Threaded Plug Gauges with Handle

    Image of Product. Front orientation. Plug Gauges. Go/No-Go Helical Insert Threaded Plug Gauges with Handle.
    Check that holes tapped for helical threads are within tolerance. You’ll sometimes hear these threads referred to as Screw Thread Insert (STI) threads. To speed up tests, these gauges have a go gauge on one end and a no-go gauge on the other. The double-ended taperlock handle makes them quick to thread and unthread. It also lets you swap in new plug gauges (not included) in place of worn ones.
    The go gauge checks the minimum internal thread size, and the no-go gauge checks the maximum. A part is within tolerance if it’s easy to thread the go gauge but difficult to thread the no-go gauge more than two turns.
    Plug Gauges with Accuracy Certificate Traceable to NIST—Gauges with an accuracy certificate traceable to NIST include verification from the manufacturer that their thread sizes are within tolerance. The certificate is also known as a certificate of compliance or a short-form certification.
    Plug Gauges with Calibration Certificate Traceable to NIST—Gauges with a calibration certificate traceable to NIST were calibrated in a lab. The certificate, sometimes called a test report or long-form certificate, details the tested measurements.
    Plug Gauges with Accuracy
    Certificate Traceable to NIST
    Plug Gauges with Calibration
    Certificate Traceable to NIST
    Thread
    Size
    Thread
    Type
    Pitch Dia.
    Tolerance
    Hardness
    Material
    Features
    For Thread Fit
    Each
    Each
    Class X Gauge
    5/16"-24
    		UNF
    		-0.0003" to 0.0003"Rockwell C70Chrome-Plated Tool SteelDouble-Ended Taperlock HandleUnified Standard Class 2B
    		7941N2100000007941N380000000
     
    back to top