McMaster-Carr logo
    Filter by
    System of Measurement
    Threaded Insert Type
    Key-Locking Insert Wall Type
    Military Specification
    End Type
    Installed Length
    Attribute Image
    DFARS Specialty Metals
    Industrial Info Compare
    For Material Thickness
    Drill Bit Size
    Attribute Image
    Number of Locking Keys
    For Tap Type
    Certification
    Hole Diameter
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    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)
    27 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.
    Extra-Thick Wall—Stronger than standard- and thin-wall inserts, use them to reduce the size of tapped holes or replace threads that have been drilled out.
    High-Strength Cadmium-Plated Alloy Steel—These inserts have the strength to stand up to high-pressure applications and a plating that helps screws thread in smoothly.
    18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.
    Inserts
    Installation
    Tools
    Thread
    Size
    For Tap Thread
    Size
    Installed
    Lg.
    Drill Bit
    Size
    For Max.
    Hole Dia.
    No. of Locking
    Keys
    Specs. Met
    Each
    Each
    Standard Wall
     
    High-Strength Cadmium-Plated Alloy Steel
    1/2"-13
    		11/16"-11
    		0.688"41/64"
    		0.641"4MS51831A10695101A13100000093904A555000000
    1/2"-20
    		11/16"-11
    		0.688"41/64"
    		0.641"4MS51831A206, NAS1395-895101A13200000———0
     
    18-8 Stainless Steel
    1/2"-13
    		11/16"-11
    		0.688"41/64"
    		0.646"4MS51831-10693904A5500000093904A55500000
    1/2"-20
    		11/16"-11
    		0.688"41/64"
    		0.646"4MS51831-206, NAS1395C893904A23200000———0
     
    Extra-Thick Wall
     
    18-8 Stainless Steel
    7/16"-14
    		11/16"-11
    		0.625"41/64"
    		0.646"4MS51832-10593904A2280000093904A27100000
     

    Screw-Locking Seize-Resistant Key-Locking Threaded Inserts for Soft Metal

    Image of Product. Bottom orientation. Threaded Inserts. Screw-Locking Seize-Resistant Key-Locking Threaded Inserts for Soft Metal.
    Create the tightest hold in aluminum and other soft metal without screws sticking. The lubricant on these inserts eases installation, and the irregularly shaped threads won’t let screws back out from vibration. Inserts have keys that drive into material to prevent them from slipping or rotating in the hole.
    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.
    Dry-Film-Lubricated Cadmium-Plated Steel—The plating creates a barrier against rust.
    Dry-Film-Lubricated 18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.
    Inserts
    Installation
    Tools
    Thread
    Size
    For Tap Thread
    Size
    Installed
    Lg.
    Drill Bit
    Size
    For Max.
    Hole Dia.
    No. of Locking
    Keys
    Specs. Met
    Each
    Each
    Standard Wall
     
    Dry-Film-Lubricated Cadmium-Plated Steel
    1/2"-13
    		11/16"-11
    		0.688"41/64"
    		0.641"4MS51831A106L97255A25600000093904A555000000
    1/2"-20
    		11/16"-11
    		0.688"41/64"
    		0.641"4MS51831A206L97255A25700000———0
     
    Dry-Film-Lubricated 18-8 Stainless Steel
    1/2"-13
    		11/16"-11
    		0.688"41/64"
    		0.641"4MS51831-106L97255A1420000093904A55500000
    1/2"-20
    		11/16"-11
    		0.688"41/64"
    		0.641"4NAS1395C8L97255A14300000———0
     

    Key-Locking Threaded Insert Installation Tools

    Image of Product. Front orientation. Threaded Insert Installation Tools. Key-Locking Threaded Insert Installation Tools, Style C.

    Style C

    Thread inserts and drive down their keys with a single tool. These tools are compatible with Keensert inserts.
    Threaded Insert Installation Tools with Spring
    Image of Product. Front orientation. Threaded Insert Installation Tools. Key-Locking Threaded Insert Installation Tools, Style C.

    Style C

    The tradespersons’ choice for installing Mil. Spec. inserts. A spring holds the sleeve under tension, so wobbles and jostles don’t interfere with a clean, professional install.
    For Thread Size
    For Tap Thread
    Size
    Style
    Features
    Each
    For Thick-Wall Inserts
    7/16"-14, 7/16"-2011/16"-11
    		CSleeve, Slotted End93904A271000000
    1/2"-13, 1/2"-2011/16"-11
    		CSleeve, Slotted End93904A55500000
     

    Air-Powered Key-Locking Threaded Insert Installation Tools

    Image of Product. Front orientation. Threaded Insert Installation Tools. Air-Powered Key-Locking Threaded Insert Installation Tools.
    Install key-locking inserts in a flash. Instead of threading and hammering inserts in by hand, these air-powered tools do both steps with the pull of a trigger. Release the trigger and the tool automatically resets, ready for the next insert. They’re compatible with Keensert inserts.
    Air Inlet
    Threaded Insert Tool
    Cycle Time, sec.
    Max. Speed
    @ 90 psi, rpm
    Wt.,
    lb.
    Average Air Consumption
    @ Pressure
    Pipe
    Size
    Thread
    Type
    Gender
    Includes
    Container
    Type
    Each
    102,0004.41.4 ft³/min @ 90 psi1/4
    		NPTF
    		FemaleOne Nosepiece for 1/4-20 Thread Size
    One Nosepiece for 3/8-16 Thread Size
    One Nosepiece for 5/16-18 Thread Size
    One Nosepiece for 10-24 Thread Size    		Plastic Case91456A121000000000
    Nosepieces
    Image of Product. Front orientation. Threaded Insert Installation Tool Nosepieces. Air-Powered Key-Locking Threaded Insert Installation Tools.
    Choose a nosepiece that matches the internal thread size of your insert.
    For Thread
    Size
    For Tap Thread Size
    Each
    For Thin-Wall Inserts, Thick-Wall Inserts, and Extra-Thick Wall Inserts
    10-24
    		5/16"-18, 3/8"-16, 7/16"-1491456A2110000000
    10-32
    		5/16"-18, 3/8"-16, 7/16"-1491456A212000000
    1/4"-20
    		3/8"-16, 7/16"-14, 1/2"-1391456A213000000
    1/4"-28
    		3/8"-16, 7/16"-14, 1/2"-1391456A214000000
    5/16"-18
    		7/16"-14, 1/2"-13, 9/16"-1291456A215000000
    5/16"-24
    		7/16"-14, 1/2"-13, 9/16"-1291456A216000000
    3/8"-16
    		1/2"-13, 9/16"-12, 5/8"-1191456A217000000
    3/8"-24
    		1/2"-13, 9/16"-12, 5/8"-1191456A218000000
    1/2"-13
    		5/8"-11, 11/16"-11, 13/16"-1691456A219000000
    1/2"-20
    		5/8"-11, 11/16"-11, 13/16"-1691456A221000000
    M5 × 0.8 mmM8 × 1.25 mm, M10 × 1.25 mm91456A621000000
    M6 × 1 mmM10 × 1.25 mm, M12 × 1.25 mm91456A622000000
    M8 × 1.25 mmM12 × 1.25 mm, M14 × 1.5 mm91456A623000000
    M10 × 1.5 mmM14 × 1.5 mm, M16 × 1.5 mm91456A624000000
    M12 × 1.75 mmM16 × 1.5 mm, M18 × 1.5 mm91456A625000000
     
    back to top