McMaster-Carr logo
    Filter by
    System of Measurement
    Thread Size
    Industrial Info Compare
    Threaded Insert Type
    For Tap Thread Size
    Industrial Info Snippet
    Attribute Image
    For Tap Type
    Thread Type
    Military Specification
    Certification
    External Locking Type
    For Material Thickness
    Hole Diameter
    Passivation
    Profile
    Sold As
    Tensile Strength
    Industrial Info Snippet
    Threaded Insert Securing Type
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    Drill Bit Size
    Attribute Image
    End Type
    DFARS Specialty Metals
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    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)
    2 Products
    About Threaded Inserts
    industrial info icon

    Choose the right threaded insert for your application and learn how to install it securely.

    Mil.-Spec. Key-Locking Threaded Inserts For Soft Metal

    Image of Product. Bottom orientation. Threaded Inserts. Mil.-Spec. Key-Locking Threaded Inserts For Soft Metal.
    These inserts are manufactured and tested to meet or compare to strict standards adopted by the U.S. military. The keys drive into aluminum and other soft metal for a secure hold that won't slip or rotate, even in vibrating vehicle or aerospace parts. These inserts are comparable to Keensert inserts.
    To install, drill and tap a hole in your material. Then, thread the insert onto the installation tool and screw it into the hole. Place the tool over the keys and hit it with a hammer to drive them in.
    Standard Wall—Stronger than thin-wall inserts, these are your go-to choice for threading most holes.
    18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Thread
    Size
    For Tap Thread
    Size
    Installed
    Lg.
    Drill Bit
    Size
    For Max.
    Hole Dia.
    No. of Locking
    Keys
    Specs. Met
    Each
    Standard Wall
     
    18-8 Stainless Steel
    7/8"-14
    		1 1/4"-12
    		1.250"1 3/16"
    		1.192"4MS51831-21093904A249000000
    Key-Locking Insert, Mil. Spec., 18-8 Stainless Steel with Thick Wall, 7/8"-14 Thread Size
    EachIn stock
     
    back to top